Batteries and inverter use at home

ronnie · Post by **ronnie** » Thu Feb 19, 2015 1:43 pm

Hi. I am hoping the collective wisdom on this forum can answer what may be a very simple question. I already have a 1500W continuous power modified sine wave inverter. It is identical to the one advertised here a while ago viewtopic.php?f=130&t=35799" onclick="window.open(this.href);return false;

I bought it for use with a caravan I no longer have. So my idea is to use it at home to power a fridge and freezer during a more extended power cut. Initially I can use a battery charger to trickle charge the battery or batteries until needed. Medium term I would rather get a solar panel or two to take care of this. The idea is just to be able to keep a few things running if Eskom really loses the plot.

I assume this is easy and perfectly safe but would appreciate any input as I saw on another thread some references to dangers using too strong an inverter....did not understand that at all and hence my question.

PS I see some good prices for solar panels on 4x4 Direct so I may just speed up the solar angle if this is all doable.

Post by **CasKru** » Thu Feb 19, 2015 2:28 pm

Always make sure that you do not run an inverter over it's nominal power output for extended periods of time (guestimate would be about 1200W for your unit).

Also when charging batteries, never charge batteries in parallel only one at a time.

WayneSchalk · Post by **WayneSchalk** » Thu Feb 19, 2015 2:31 pm

Hi Ronnie.

1500w might be a bit light for fridges? I have a 2000va pure sign wave, that runs off 12v. for now I have 2 x 100Ahr deep cycle batteries that its connected to, but this one has a built in charger so it works like a ups.

But I will only run my lights, TV, electric fence, gate and garage motor off it. I think even mine will be a bit light for my fridges. I am planning on doing all the wiring this weekend so I will put a clamp meter on the fridges and have a look.

Good luck.

Mr_B · Post by **Mr_B** » Thu Feb 19, 2015 2:37 pm

Hi Ronnie,

I'm busy with a similar exercise, mainly for lighting and tv+dtsv during load-shedding. 2 things to note, I heard that modified sine wave inverters can be harmful to certain electronic devices such as TV's and computers... and a fridge/freezer has a rush-in/start-up current demand typically 6-8 times higher than the devices continuous wattage rating. So a 300w fridge could require 1800-2400w just to get going... I'm not sure if a 1500w inverter will be able to handle the load... that being said ChrisF did manage to run a 700w pool pump off his 1500w pure sine wave inverter(for 10 minutes or so).

I'm sure the other solar fundi's will provider better advise!

ronnie · Post by **ronnie** » Thu Feb 19, 2015 2:39 pm

CasKru wrote:Always make sure that you do not run an inverter over it's nominal power output for extended periods of time (guestimate would be about 1200W for your unit).

Also when charging batteries, never charge batteries in parallel only one at a time.

Thanks for that Cassie....never knew about not charging in parallel. Would that apply to connecting a solar panel too? If that is the case my best bet would be to start off with just one battery for simplicity.

ronnie · Post by **ronnie** » Thu Feb 19, 2015 2:41 pm

Mr_B wrote:Hi Ronnie,

I'm busy with a similar exercise, mainly for lighting and tv+dtsv during load-shedding. 2 things to note, I heard that modified sine wave inverters can be harmful to certain electronic devices such as TV's and computers... and a fridge/freezer has a rush-in/start-up current demand typically 6-8 times higher than the devices continuous wattage rating. So a 300w fridge could require 1800-2400w just to get going... I'm not sure if a 1500w inverter will be able to handle the load... that being said ChrisF did manage to run a 700w pool pump off his 1500w pure sine wave inverter(for 10 minutes or so).

I'm sure the other solar fundi's will provider better advise!

I am not worried about needing TVs and computers to work at home; just don't want the beer to get warm and the food to spoil. I heard that about fridges but thought it can be overcome by not connecting both at once. Problem with that is that they do not run continuously so may well start up at the same time again after a while.

ronnie · Post by **ronnie** » Thu Feb 19, 2015 2:43 pm

WayneSchalk wrote:Hi Ronnie.

1500w might be a bit light for fridges? I have a 2000va pure sign wave, that runs off 12v. for now I have 2 x 100Ahr deep cycle batteries that its connected to, but this one has a built in charger so it works like a ups.

But I will only run my lights, TV, electric fence, gate and garage motor off it. I think even mine will be a bit light for my fridges. I am planning on doing all the wiring this weekend so I will put a clamp meter on the fridges and have a look.

Good luck.

I like the idea of the built in charger but in the back of my mind I am still considering doing this as a very small scale off the grid exercise using solar panels

WayneSchalk · Post by **WayneSchalk** » Thu Feb 19, 2015 3:01 pm

ronnie wrote:
WayneSchalk wrote:Hi Ronnie.

1500w might be a bit light for fridges? I have a 2000va pure sign wave, that runs off 12v. for now I have 2 x 100Ahr deep cycle batteries that its connected to, but this one has a built in charger so it works like a ups.

But I will only run my lights, TV, electric fence, gate and garage motor off it. I think even mine will be a bit light for my fridges. I am planning on doing all the wiring this weekend so I will put a clamp meter on the fridges and have a look.

Good luck.
I like the idea of the built in charger but in the back of my mind I am still considering doing this as a very small scale off the grid exercise using solar panels

Mine is purely for security, winter is coming so I dont want to come home to total darkness, at least with this it changes over automatically and my security lights will stay on.

Post by **CasKru** » Thu Feb 19, 2015 4:02 pm

ronnie wrote:
CasKru wrote:Always make sure that you do not run an inverter over it's nominal power output for extended periods of time (guestimate would be about 1200W for your unit).

Also when charging batteries, never charge batteries in parallel only one at a time.
Thanks for that Cassie....never knew about not charging in parallel. Would that apply to connecting a solar panel too? If that is the case my best bet would be to start off with just one battery for simplicity.

Your system will charge as well as your weakest battery. In other words, if you have two batteries in parallel and charge them, and the one is a bit iffy, the will both only charge as much as the iffy battery allows.

Mr_B · Post by **Mr_B** » Thu Feb 19, 2015 5:27 pm

CasKru wrote:Also when charging batteries, never charge batteries in parallel only one at a time.

Cassie, I've seen diagrams on the internet that show how to connect a single charger to batteries connected in parallel, like this:

http://www.gearseds.com/files/twobat_onechgr2.pdf" onclick="window.open(this.href);return false;

Would this be ok?

Post by **Mud Dog** » Thu Feb 19, 2015 6:35 pm

That's exactly the same as an ordinary parallel setup, Bretton, and what Cassie said would still apply. If you were to disconnect one of the bridges, then you could charge them separately (one after the other with one charger or both at the same time with two chargers).

With battery back-up, if one is going for more than just TV / computer, then you would need more battery capacity and that means multiple batteries. In that case you are forced to go either 24 or 48 volts (batteries in series) or the parallel battery system. That's why batteries should all be installed or replaced new at the same time in order to avoid having one that's much weaker than the others.

Remember also that a single battery is in itself a series of cells, and a battery is only as strong as the weakest one. Now couple that with a parallel battery setup, and you can reason that the whole battery bank will only be as strong as the weakest cell within one of those batteries.

Sometimes cannot be avoided, unfortunately, but a 48V system (with suitable charge controller and inverter) for larger draw is a better option.

ronnie · Post by **ronnie** » Thu Feb 19, 2015 6:45 pm

Would you guys suggest that a better long term solution is to ditch the inverter and buy a 48V to 220V inverter and then connect batteries in series?

Post by **Mud Dog** » Thu Feb 19, 2015 8:51 pm

Don't ditch the inverter - it can be used in a "starter" system (like I did) or in your vehicle (I have one in each vehicle, just in case and they've come in handy a few times.

If you can swing it within your budget, I would suggest to go as far as you can towards a goal of grid independence. If that means multiple batteries with sufficient PV panels to recharge them, then the higher voltage system makes sense.

As I see it, all dependant on your budget, the priorities are:

1. A basic system to be able to cope with load shedding. Fridges and freezers can manage a 2 or 2½ hour shed. A gas stove is a good option for alternative heating / cooking. A solar assisted geyser (solar heating panels) is almost a must. So for solar electricity, that leaves lighting and perhaps TV and computer / router (or modem if that's what you have).

2. An expanded or bigger system that can take over some electrical applications from the grid completely on a permanent basis. You can add to it as you go along, relieving your grid demand.

3. A totally independent system (big bucks).

ronnie · Post by **ronnie** » Fri Feb 20, 2015 4:56 pm

Sorry...another question

This inverter has a nut to which you can connect an earth wire....my smaller inverter I sometimes take along in the car does not. Do I have to attach an earth wire and if so what is the best way to do this? The inverter will be wall mounted in an outside room.

Vlak vark · Post by **Vlak vark** » Fri Feb 20, 2015 7:39 pm

buy yourself a gas freezer and fridge and use the inverter for the lights

Post by **Mud Dog** » Fri Feb 20, 2015 8:16 pm

Connecting the 'earth' on the inverter is not absolutely necessary, it's just a little added safety feature which grounds the body of the inverter. If it has the connection I would connect an earth wire.

Post by **pietpetoors** » Fri Feb 20, 2015 8:43 pm

Running the fridge is not the problem, starting it is the problem. My fridge uses 5 amps = 1150 watts to start and 0.8 amps = 184 watts to run.
If your inverter is the same as ours it should start the fridge. It is rated 1500 watt but can handle peaks (like starting the fridge) of 3000w.
Not good to stress any inverter more than 80% of capacity so make it peak of 2400 watt spike and 1200 watt continuous.
To maintain the 184watts for running the fridge you will draw about 17 amps which means you will need good batteries for running 15 amps continuously.
Not accurate but good thumb suck estimate is that you will drain 25% of a 105Ah battery within 2 hours continuous run. But the reality is that a fridge do not run all the time, it switches on and off all the time. You will find a freezer switches on and off more frequently, thus uses more energy. (or at least mine does)

So for my double door fridge/freezer combo it will work, but not much else.

As for running lights, it is not cost effective to get a huge inverter to run incandescent lights if you can invest in LED globes and then run smaller inverter to power lights that use a tenth of the poower of a traditional lamp. Investment in LED lights will save you on inverter and battery cost. So LED lights and off grid power goes hand in hand.

KOBUSL · Post by **KOBUSL** » Sat Feb 21, 2015 3:07 pm

Ronnie, wat die manne hierbo se is waar. Maar my vraag : met load shedding is die krag so 2 tot 2,5 ure af. As jy nou VINNIG jou bier uit die yskas haal , is dit mos nie nodig dat hulle loop nie ? Jy moet net die familie leer om te besluit wat hulle in die yskas soek voor hulle die deur oopmaak, en dit vinnig uit te haal.

Om afhanklik van Eskom te werk is 'n hele ander $torie. Ten eerste sal jy genoeg batterye moet he om jou huis aan die gang te hou, dan sal die grootte van die inverter nie saak maak om die yskaste aan die gang te kry nie. Terloops, moenie eers dink aan iets anders as pure sine wave nie, die "modified" is maar net 'n trooster, en maak marakkas met baie toestelle. Sonpanele is op die oomblik te koop vir ongeveer R 8 per watt, die kleiner modelle ingeveer R 10/w. Ek sien die aanbeveling vir 'n normale woonhuis is ongeveer 'n 3 tot 5 KW stelsel.

Weereens, daar is baie opsies. As jy jou inverter wil gebruik, sou ek se 'n paar batterye, so twee 235 w sonpanele en 'n controller van 30 amp /12v. Sit daarby LED ligte, geen stowe/pompe/yskaste of ander kragvreters nie, en jy behoort loadshedding , met 'n TV aan, maklik te deurstaan.

Sou jy groter gaan, is dit baie meer raadsaam om vir 'n 48v sisteem as 'n 12v siteem te gaan. Hoe hoer die DC volts is wat jy wil omskakel na 220v, hoe meer effektief ( en natuurlik duurder ) is die sisteem. ( Batterye $$$ ) Ek gebruik beide sisteme ( lees : skoolgeld ) en dit dryf my rekenaar en sekuriteitsisteem permanent, heeltemal onafhanklik van Eskom. Onthou net : koop by erkende handelaars met 'n skoon geskiedenis, op die oomblik is daar meer fly-by-nights in die mark as oliekolle op 'n Landy eienaar se oprit.

Riaan99 · Post by **Riaan99** » Fri May 01, 2015 10:57 am

Awesome topic dankie mense! Ek is hard besig om kwotasies bymekaar te maak vir 'n inverter (2500-3000W)

4x4 direct (uitverkoop)

http://www.4x4direct.co.za/solar-power- ... c-180_183/" onclick="window.open(this.href);return false;

Weet iemand van 'n plek wat ook goeie pryse het?

WayneMan · Post by **WayneMan** » Fri May 01, 2015 8:14 pm

I have access to a lot of 2nd hand batteries from a very large commercial UPS. I have no idea how to use them or how to hook them up at home to be beneficial during a power outage.
Can someone give a heads up on where to start and how to go about this. I know I will need to get an electrician, maybe some solar panels, a charger of sorts and maybe and inverter.
And advice would be appreciated. Thanks

Willem01 · Post by **Willem01** » Fri May 01, 2015 8:35 pm

Hier is baie goeie raad, iets om in gedate te hou ek het n "gas hob" laat insit en hulle het die plug afgeknip en op die elektriese stoof se draad gekoppel, nou die hob start met daai elektriese krag,,maaaaaar toe loadshedding inskop en die krag is af kon ek nie die bleddie gas hob gebruik nie want da kom nie gas uit met al die safety features nie en da is geen spark nie,,,,,ek het toe maar wee die draad afgeknip die plug terug gesit en dit by die inverter ingeplug en kon toe die gas hob gebruik....
so die modified inverter werk goed en dis maar n klien enetjie,,,soos alreeds gesê kry n pure sine wave inverter sommer n 2kwatt 1 van die begin af as jy daai yskas wil laat aanbly

Post by **Family_Dog** » Sat May 02, 2015 1:02 pm

Wayne, depending on the size UPS or Inverter that you get - and that is dependent upon your requirements - you would hook them in series (i.e. = + to -) for higher DC voltages. A 1000w Inverter is already a strain on 12v batteries so try get 24v or better still a 36v or 48v unit. You would need four batteries for a 48v system but then also ensure your proposed Inverter can charge them.

-F_D

Riaan99 · Post by **Riaan99** » Sat May 02, 2015 3:52 pm

Family_Dog wrote:Wayne, depending on the size UPS or Inverter that you get - and that is dependent upon your requirements - you would hook them in series (i.e. = + to -) for higher DC voltages. A 1000w Inverter is already a strain on 12v batteries so try get 24v or better still a 36v or 48v unit. You would need four batteries for a 48v system but then also ensure your proposed Inverter can charge them.

-F_D

Okey, so ek het nou 'n FRIS inverter, 4000W...ek kyk nou na 2x 200AH batterye maar weet nie watter charger om te gebruik nie

.

Die inverter is straight forward, slegs inverter, geen fancy goed by nie...my plan is om 'n unit te bou soos 'n UPS, waar as die krag af gaan moet hy klaar aan wees..(wil nie hê die yskaste moet daagliks af gaan en oor 'n minuut weer aangesit word nie)

Is daar nie 'n ding wat my batterye veilig kan laai, en die inverter af sit as die batterye onder 10.5V gaan om te keer dat hul nie verniel nie?

..die naaste wat ek kry ies hierdie: http://www.omnitech.co.za/chargers.htm" onclick="window.open(this.href);return false;

ChrisF · Post by **ChrisF** » Sat May 02, 2015 4:23 pm

Mr_B wrote:
CasKru wrote:Also when charging batteries, never charge batteries in parallel only one at a time.
Cassie, I've seen diagrams on the internet that show how to connect a single charger to batteries connected in parallel, like this:

http://www.gearseds.com/files/twobat_onechgr2.pdf" onclick="window.open(this.href);return false;

Would this be ok?

I have posted on various similar threads over the last few months.

These replies have been based on a background of industrial electrical installations - air conditioning artisan by trade.

Later my career moved on and I got more experience in 12V systems and basic chargers and inverters.

Having done a couple of 4x4 fitouts I thought I knew it all ....

Thus I grabbed the opportunity to attend a 2 day session presented by MicroCare - http://microcare.co.za/" onclick="window.open(this.href);return false;

Now I thought I knew a thing or two about "energy", "energy conservation" and the basics of "alternative energy" ... I even knew just a little bit about electrical safety and the various electrical regulations hampering the implementation of alternative energies ......

It took all of 5 or maybe 6 minutes to realise just how far I am out of my depth !!!!!! I take little consolation from the fact that few of the attendants knew more than me ......

In another reply I will tell more of the general concepts.

In THIS reply - I will only look at "parallel" .... and the issues of charging and maintaining your batteries.

Some pointers, in no particular order :

- add a new battery to an older battery - in little more than a week it will be the "same age" as the OLDER batteries !! So when working with battery banks, use batteries of the exact same age and condition if at all possible.

- working with TWO of batteries in PARALLEL - this is what we think of as two batteries in parallel (thinking of a 2nd AND 3rd battery) :

batterye.jpg: (23.74 KiB) Downloaded 354 times

When industry supplies a larger system it may well look like this :

batterye 4 (Large).jpg: (28.47 KiB) Downloaded 354 times

The reason for this is as follows - with both the positive and negative connected to the first battery the following happens, battery 1 charges 100%, with battery 2 charging to about 99%, and battery 3 only charging to about 98%, and only 97% for battery 4 - on the FIRST cycle. The next cycle is another 1% down per battery, and again and again ... Thus after a good many cycles the last battery hardly charges to 50% !!

By connecting the + to the first battery and the - to the last battery the this phenomena is kept to a minimum.

No do understand that industrial chargers have an equalisation mode, typically every 2 weeks. This "over charges" the batteries for a short period to try and get all batteries to a 100% state of charge.

As our 4x4 chargers dont have these extra charge modes our only option is to use this method of charging for a 2nd and 3rd battery -

batterye 2.jpg: (27.76 KiB) Downloaded 354 times

ChrisF · Post by **ChrisF** » Sat May 02, 2015 4:44 pm

Series vs Parallel ....

Okay, from this point forward I will NOT be talking of 4x4 2nd battery installations - though for most of the readers here THIS is what our understanding is based on.

FACT is that once we start on the road to use "battery power" inside our home the game CHANGES !!

For this post, let me stick to series vs parallel -

For home systems the POWER (capacity of your installation) is typically used to determine the voltage of the battery bank. The follwoing being a guideline -
- 1kW 24 to 36V
- 3kW 36 to 48 V
- 5kW 48 V

YES, you do get a 12V 1kW setup, but this is considerably more expensive than the 24V setup. This relates to the current draw .....

Now our 4x4 brains would immediately say, okay ... 2 batteries in series for 24V and then a couple of parallel banks ....

And it is no surprise that the industrial suppliers DONT follow this route !!!!!!!!!!!

Due to the issues with charging batteries in parallel they rather stay with batteries in SERIES ..... but how far are two 105Ah units going to get you ....

These industrial okes think DIFFERENTLY !!!

Working with round numbers .... a typical 2 to 3 bedroomed home would require about 880Ah at 48V to run for one full day without Eskom (yes, more than the classic load shed we are talking about). Their first offer of a solution to you may well be 24 off 2V batteries in Series. EACH battery with a capacity of 900A.h ! WOW !!!

and only R 2 500 PER battery, if you choose the cheaper units ..... the REAL stuff is over R 20 000 PER battery ... at 24 batteries ..............

ChrisF · Post by **ChrisF** » Sat May 02, 2015 6:04 pm

DISCLAIMER - We ARE talking of HOUSE WIRING here. A topic which is WELL REGULATED.

And if any person, be it your kid or your domestic worker gets killed by an electrical fault the authorities should check to see if it is as a result of a "fault" or an "illegal installation".

Now this is where the game gets TRICKY !!

220V is clearly defined and regulated.

The use of DC (battery systems) and inverters and PV panels and and is NOT clearly defined in the Wiring Code. The Wiring Code is currently being updated with this in mind. BUT updating the wiring code is proving a thorny issue as each municipality deals differently with the topic of PV installations. The presentation by Brian Jones highlights some of the issues at play - it is a 585kb file, my limit is 300kb. I did add an extract of the presentation, highlighting the issues we NEED to know -

In terms of the compliance requirements note the following (while the wiring code is being re-written) -
- COC for the 220V side of the wiring
- Professional Engineer to sign off on the rest of the installation
- also note that the inverter must conform to a specific NRS standard. (it costs close to a R 1 000 000 to get a unit through all the SABS tests to actually get this certification ...)

Okay, take a step back and look at the bigger picture. We are talking of one of two extreme options :

1) PV installation with a battery bank, wired into the house wiring, to provide backup power during eskom outages The key phrase here that it is wired into the house wiring. Now all the rules and regs kick in, to ensure your families safety.

2) The other extreme end would be to use something like the 1kW UPS from MicroCare - http://microcare.co.za/pure-sine-wave-1kw-ups/" onclick="window.open(this.href);return false;
The key here is that it is a "device", NOT part of the house wiring.

So WHAT does this actually mean to you and I ????????

For ME the main frustration is that with our politians wasting time fighting about the colour of an overall worn to parliament the real issues dont get the attention it deserves ! With so many rules up in the air it is a night mare to try and second guess what may be legal in 6 weeks, 6 months or heaven forbid in 6 years .... Whatever you install TODAY has a 99% chance to incur more costs once these new regs finally are penned.

Okay, so like me, you are fed up of planning your free time around incompetence called eksdom ..... so WHAT to do ?

Speak to the likes of MicroCare, or Victron, or Schneider, or any of the other top installers, and you will find that dependant on where you live in SA the "legal installation" is different from dorp to dorp ..... I am looking at over R 300 000 for a LEGAL system in the Cape

In some other cities I could get the same result (saving in power and backup) for 100 to 150k. NOTE - these would then be subject to additional costs once the wiring code is finally updated.

And now it begins to make sense why I am seriously considering the MicroCare 1kW UPS unit. But at about R10k this is hardly cheap - AND this is only good for the tv and PC's .... I could also run a "bedlamp" or two for emergency lighting from this.

The fridges wont be run from this.. But then again, a fridge dont need backup power, not as long as a loadshed remains at 2 hours ....

So me being me I cant help but think that 10k is a lot of money and I looked further at how else (cheaper) I could achieve the same outcome. It is a very tempting option .... afterall, WHAT is a UPS ? In essence it is a "charger", "batteries", and "inverter", and let's not forget some pretty good electronics to do the change over in record time ....

I spoke to a UPS supplier, who regularly supplies us with equipment for electronic and computer rooms. With the focus on load shedding he does NOT want to supply us with UPS units !! I am now talking top quality European products. The hard reality is that the classic UPS is made for high power output for SHORT periods - just long enough for the generators to kick in. The electronic components work way too hard when used for 2 hour loadshedding, AND the batteries are pushed way past their design specs. His exact words to me: "To actually get it to work, you have to oversize the battery bank. Causing other issues with the charging and keeping the batteries in sync."

We carried on talking about the possible affordable solutions .....

He was ADAMENT about using only TOP quality inverters, as the wave quality, the tolerance of the frequency, the voltage frequencies etc etc are VITALLY important to the power supplies of your electronic equipment at home !! A poor quality inverter may end up costing you a LOT of money !! He swears by the Victron inverters - R 2 000 for a 300W inverter.

your batteries are going to be an expensive investment. so DO invest in a DECENT charger. Was interesting to once again hear a top specialist confirm that the best charge current should be LESS than 10% of the battery capacity. The charger he recommended was R 2 200.

Add the price of two batterie and this quality set wont cost much less than the MicroCare UPS ... AND then it is still a technically illegal DIY setup, which must still be switched manually.

And with a 4 year old godson running around our home and yard I am most hesitant of a DIY installation that could potentially put him in harms way .... by the time I have built all the parts into a safe enclosure and added some relays etc to make the system safe it will cost me more than the shop bought version.

ChrisF · Post by **ChrisF** » Sat May 02, 2015 6:16 pm

For the heck of it I spoke to a friend busy with a generator quote for a client, and also to an electrician about the costs of doing a fully legal auto change over system with drop out relays for non essensial loads ...

VERY difficult to get quotes on gennies at the moment, short of going out on tender. The problem relates to the change in exchage rate, and then also the massive shortage of quality products .....

the best questimate at this stage (can hopefully update this soon when the actual tenders comes in):
- 20k for a decent, semi quiet, genny for a normal house. capable of most of the home load, excluding the stove and geyser
- another 5 to 10k to connect it to your DB board, the change over gear, drop out relays for the stove and geyser, etc etc .... this depends a LOT on your layout, where will the genny be housed, cable route from here to the DB, how easy/possible it is to fit/hide a second DB for the change over gear etc.

YES, this comes with a fuel bill and maintenance costs !! .... not as if batterie replacements are free ....

ChrisF · Post by **ChrisF** » Sat May 02, 2015 6:42 pm

Time to recap ....

eskom pays performance bonusses but switch off our power regularly ....

some of us "like" to be able watch tv, or surf the forum during a load shed ...

for some missing the last 30 minutes of the "game" is not an option .....

some WORK from home, and MUST get the invoices and quotes out, even if that means doing nothing from 8 to 10 at night, to do the admin until midnight, and then back out on the road early morning ......

some need power for respirators, like the gent that died in Bloemfontein ......

some have 20k worth of meds in the fridge that will go off if the outage exceed 3 or 4 hours ....

Thus people start to consider ways to survive eskom.

OPTION 1 - The R10k UPS from MicroCare option should really do the job for most home needs.

The recurring problem is that a solution is found for the actual "need" .... then the rest of the family jumps on the band wagon and suddenly everybody wants to add another item/device and before you have finished watching the last 30 minutes of that game everybody has run a lead to your UPS and tripped the system, and killed the batteries ....

So REALLY THINK before you start throwing money at this problem .... WHAT is the FAMILIES power requirements during a loadshed ?

OPTION 2 - Generator installation, 20 to 30k (for the proper auto change over and larger genny) ....

I would hate to hear the noise of every 2nd or 3rd house installs a genny ... There are already 2 of the 4 homes in our cul-du-sac that has gennies (and mine is currently the loudest). Okay, both of these are the smaller variety that powers small loads. These are more than a small pain to own - noisy, gotto have fuel in a jerry can, spare light be able to decant the fuel during a power failure, rolling out a lead. BUT, you can watch that game ....

But again - what about the rest of the family and their power needs ?

Thus the 25k installation may well be a much better solution than a cheapy 5 to 10k small genny, with extension lead.

OPTION 3 - PV installation

This is currently a mine field with all the regulatory uncertainty ....

Add the costs of 50 to R300k and there are some snake oil salesman making a killing at the moment ... with the home owner lined up for massive costs when he tries to sell the house ....

dont get me wrong - EXCELLENT technical options.

WayneMan · Post by **WayneMan** » Sat May 02, 2015 8:06 pm

Thanks for the very thorough explanation. I was thinking along the same lines that even though I have access to very cheap 2nd hand French imported batteries it would still be a very costly exercise to get something working that is compliant and safe.
I'm really not too phased about load shedding. Don't get me wrong that it does inconvenience me and annoy me, but compared to everyone else with their generators solar etc etc I not that worried. I will cook on gas have a solar geyser and I don't have TV so life is pretty simple for me fortunately.

WayneMan · Post by **WayneMan** » Sat May 02, 2015 8:10 pm

I think all I should be doing is hooking up one of the beeeeg batteries to a few LEDs so I can see what I'm doing.
What is a very basic or simple solution to charge one or 2 of these batteries via solar? What do I need to aquire and how do I do it?

Oupa Stig · Post by **Oupa Stig** » Sat May 02, 2015 8:47 pm

http://www.forbes.com/sites/jeffmcmahon ... ear-power/" onclick="window.open(this.href);return false;

I hope this link works - Tesla's new battery packs - might take a while to reach us and to prove itself though...

KOBUSL · Post by **KOBUSL** » Sat May 02, 2015 9:44 pm

WayneMan wrote:I think all I should be doing is hooking up one of the beeeeg batteries to a few LEDs so I can see what I'm doing.
What is a very basic or simple solution to charge one or 2 of these batteries via solar? What do I need to aquire and how do I do it?

Wayene, you get smalish inverters with chargers and PV input. Some can even start your gennie. Hook up a pair of batteries and couple it legally up to your light circuit in the DB bord. Then : when its day time , the panels will charge the batteries. At night time the inverter will charge the batteries. Make the lights run off the inverter permanently. If you use only LED's, darkness will never bother you. For lights only 1x12 v or 2x12v batteries ( for a 24v system ) and a 1 KW inverter will be more than sufficient. Presently I run a 12v 1500w system with 2x105ah batteries in parallel. Good enough for 7e Laan, news and reading. ( We are old, go to bed early )

And what Chris pointed out about charging, TAKE NOTE. True 's Bob.

Post by **Mud Dog** » Sun May 03, 2015 2:45 am

When contemplating my setup, I had grand ideas but had to change my plans after looking more closely at some facts and figures. A fully grid independent installation is not going to save you money unless you're looking at a 15 to 20 year term, so that idea flew out the window and I looked more at the minimal requirements to survive load shedding without too much inconvenience while also saving in the longer term. To this end, I did the following ...

2 x 80W PV panels charging 2 x 102 ah batteries in parallel (Connected as Chris has suggested) using a 20A controller (12V system)

2 x 80W PV panels charging 2 x 102 ah batteries in series using a 20A controller. (24V system)

The 12V unit supplies a stand alone 12V circuit (fused) for LED lighting in every room of the house. It's more than adequate and I have left almost all the lights on for 12 hours straight with no issues. This system works every day irrespective of shedding and I hardly ever use Eskom for lighting.

The 24v system feeds a 1000W pure sine wave inverter on a stand alone 220v circuit (20A circuit breaker) with plug points for TV's and computers, router & printer. This system is essentially for load shedding and is manually switched on and plugs are manually transferred. Might be a slight inconvenience doing it manually, but it cuts out a lot of red tape and extra expense. I do on occasion use this for one of the TV's irrespective of shedding.

Fridges / freezers are off during load shedding and opened as little as possible. We have a gas stove for back-up. Geyser is assisted with solar heating (a DIY solar installation that works quite well but has room for improvement.

My capital lay out has swollen a bit since I posted about this in another thread, but even so it's not a train smash. Doing it myself with total material costs of about R12½k, I should recover that lay out fully over the next 1½ to 2 years - after that it's cash in my pocket until I need to replace batteries.

Costs:
Approx R8K for panels and batteries
R900 for two controllers
Approx. R2½K for inverter / cables / plug-points / switches / fuse and breaker / frames for mounting panels on roof plus a few incidentals here and there.

Future plans:
The existing geyser solar heating to be replaced with a commercial unit with evacuated tubes. The old DIY unit will be used on a separate system for out buildings (electrical supply to this 2nd geyser is currently switched off and will remain so).

The installation of four more PV panels supplying a grid tied inverter that puts some power back into grid and reduces my monthly consumption of grid energy even further. (I already have a smart meter installed).

At this point I have abandoned the idea of working towards total grid independence but might have to revisit this issue depending on future grid energy costs and stability of supply.

ChrisF · Post by **ChrisF** » Sun May 03, 2015 10:35 am

Oupa Stig wrote:http://www.forbes.com/sites/jeffmcmahon ... ear-power/

I hope this link works - Tesla's new battery packs - might take a while to reach us and to prove itself though...

been following these posts in the technical section of News24 for a while

VERY interesting times !!!!!

sadly may well be a few years before it becomes economically viable ..... BUT, if it works have as well as presented then this certainly is the tecchnology the WORLD has been waiting for - - - which basically means the chinese will make it cheaper before long .....

ChrisF · Post by **ChrisF** » Sun May 03, 2015 10:41 am

KOBUSL wrote:
WayneMan wrote:I think all I should be doing is hooking up one of the beeeeg batteries to a few LEDs so I can see what I'm doing.
What is a very basic or simple solution to charge one or 2 of these batteries via solar? What do I need to aquire and how do I do it?
Wayene, you get smalish inverters with chargers and PV input. Some can even start your gennie. Hook up a pair of batteries and couple it legally up to your light circuit in the DB bord. Then : when its day time , the panels will charge the batteries. At night time the inverter will charge the batteries. Make the lights run off the inverter permanently. If you use only LED's, darkness will never bother you. For lights only 1x12 v or 2x12v batteries ( for a 24v system ) and a 1 KW inverter will be more than sufficient. Presently I run a 12v 1500w system with 2x105ah batteries in parallel. Good enough for 7e Laan, news and reading. ( We are old, go to bed early )

And what Chris pointed out about charging, TAKE NOTE. True 's Bob.

Kobus as I said - VERY frustrated at the pace of the new rules coming into play !!

Right now I have one of three choices in the Western Cape - based on what Brian Jones said :
- forge ahead and do my own thing and just ignore all the rules ...
- get a professional engineer to sign off on the installation, working with a number of of these I wont repeat here what they say ...(relates to risking their professional insurance for a "sign off" fee)
- wait until the new wiring code comes out and then see what can be done legally .....

YES, I do believe your thought pattern IS on the right track .... one light circuit, and maybe even one plug circuit ..... maar ek wag nou vir daai nuwe regulasie om uit te kom ....

ChrisF · Post by **ChrisF** » Sun May 03, 2015 11:01 am

WayneMan wrote:I think all I should be doing is hooking up one of the beeeeg batteries to a few LEDs so I can see what I'm doing.
What is a very basic or simple solution to charge one or 2 of these batteries via solar? What do I need to aquire and how do I do it?

My neighbour, who is a registered electrician, is currently doing the following.

50W PV panel (I prefer something closer to 2x80W panels)
regulator
1x105Ah battery
A totally new light circuit, NOT tied into the existing 220V light circuit
3-button remote control for three circuits

At the moment they USE the 2 off LED downlighters in the main bedroom. These are bad for normal light as it is to directional, which is exactly why it is BRILLIANT as reading lamps.

The second circuit provides light for the passage and general areas. Ample for moving about the house under normal conditions.

The third is a long string of LED's in the wet-kitchen. Ample light for this area.

He did this install for light during load shedding. I keep on telling him to add two more circuits, then he can effectively leave OFF all the 220V lights. THIS is when he would need to up from the 50W panel.

This system wont affect the COC under the current rules - though technically the 12V circuit is not legal, not until the new regs comes into play. The nice thing here is that as long as you use the correct wire size - FOR DC !! - and standard practice for wire type and connections etc etc then this type of installation should be 99% compatible with whatever the new regs throw our way ....

COST -
50W panel - R 600 (rather put down 2k for 2x80W panels)
regulator - anything from R300 to R 1250 .... leaning towards the R500 units.
1x105Ah battery - R 1 800, from 4x4Direct
fuse box and wiring - few hundred rand ...
The remote controlled switch unit - R 300 + the cost of a few remotes
Lights - for the emergency lighting the cost would start at R200 ... and running up fast if mommy wants some fancy looking 12V light units.

For US - the wife and I dont really need a lot of lighting during a load shed. And our camping lights does the job ... HAVE cost me a few hundred rand in AA batteries already !!!

For my neighbour - with a 4 year old in the house it HELPS to have standby lighting on the ready. In another few years the kid might NEED lighting to be able to complete home work for school .... and so the "need" for each family continually change. At least he CAN add a downlighter or two for the kid's study area

louis fourie · Post by **louis fourie** » Sun May 03, 2015 11:28 am

ChrisF wrote:
This system wont affect the COC under the current rules - though technically the 12V circuit is not legal, not until the new regs comes into play. The nice thing here is that as long as you use the correct wire size - FOR DC !! - and standard practice for wire type and connections etc etc then this type of installation should be 99% compatible with whatever the new regs throw our way ....

Chris

What is the correct wire size?

louis fourie · Post by **louis fourie** » Sun May 03, 2015 11:34 am

In dieselfde lyn wat Wayne dink

Baie binnekort (wag net nog vir oordrag) gaan die 3 fase transformer my R1200 per maand kos en dan het ek nog nie eers 1W se krag gebruik nie

. My krag verbruik by my vorige huis, 9 maande terug, was 'n R1000 per maand.

1) Ek het lig nodig

2) Ek het reeds 'n A+++ Bosch yskas en dink daaraan om 'n A+++ vrieskas ook te kry.

3) Rekenaar (laptop) en printer (3 ure per dag)

4) TV en DVD speler (2 ure per dag)

'n 5 KW/h genie moet dan

a) Die wasmasjien (3 keer per week)

b) so nou en dan 'n strykyster

c) my sweismasjien

d) boorgat pomp vir nou (sal oorskakel solar toe op 'n later stadium) trek

Stoof is op gas, en gas geysers (Sal vervang word met solar ook op 'n later stadium)

My vrae:

i) Hoeveel batterye het ek nodig vir no. 1 tot 4 hierbo, ± watse groote inverter, en hoeveel sonpanele?
ii) sal so 'n "setup" kan werk?

ChrisF · Post by **ChrisF** » Sun May 03, 2015 11:35 am

Mud Dog wrote:When contemplating my setup, I had grand ideas but had to change my plans after looking more closely at some facts and figures. A fully grid independent installation is not going to save you money unless you're looking at a 15 to 20 year term, so that idea flew out the window and I looked more at the minimal requirements to survive load shedding without too much inconvenience while also saving in the longer term. To this end, I did the following ...

2 x 80W PV panels charging 2 x 102 ah batteries in parallel (Connected as Chris has suggested) using a 20A controller (12V system)

2 x 80W PV panels charging 2 x 102 ah batteries in series using a 20A controller. (24V system)

The 12V unit supplies a stand alone 12V circuit (fused) for LED lighting in every room of the house. It's more than adequate and I have left almost all the lights on for 12 hours straight with no issues. This system works every day irrespective of shedding and I hardly ever use Eskom for lighting.

The 24v system feeds a 1000W pure sine wave inverter on a stand alone 220v circuit (20A circuit breaker) with plug points for TV's and computers, router & printer. This system is essentially for load shedding and is manually switched on and plugs are manually transferred. Might be a slight inconvenience doing it manually, but it cuts out a lot of red tape and extra expense. I do on occasion use this for one of the TV's irrespective of shedding.

Fridges / freezers are off during load shedding and opened as little as possible. We have a gas stove for back-up. Geyser is assisted with solar heating (a DIY solar installation that works quite well but has room for improvement.

My capital lay out has swollen a bit since I posted about this in another thread, but even so it's not a train smash. Doing it myself with total material costs of about R12½k, I should recover that lay out fully over the next 1½ to 2 years - after that it's cash in my pocket until I need to replace batteries.

Costs:
Approx R8K for panels and batteries
R900 for two controllers
Approx. R2½K for inverter / cables / plug-points / switches / fuse and breaker / frames for mounting panels on roof plus a few incidentals here and there.

Future plans:
The existing geyser solar heating to be replaced with a commercial unit with evacuated tubes. The old DIY unit will be used on a separate system for out buildings (electrical supply to this 2nd geyser is currently switched off and will remain so).

The installation of four more PV panels supplying a grid tied inverter that puts some power back into grid and reduces my monthly consumption of grid energy even further. (I already have a smart meter installed).

At this point I have abandoned the idea of working towards total grid independence but might have to revisit this issue depending on future grid energy costs and stability of supply.

Andy every so often we get the opportunity to learn from others ....

THIS time I was VERY fortunate

I have a friend that has done the Schneider whole house thing. Technically BRILLIANT. Price ... we need a "bleeding icon". Regs .... uhm ja ....

Another friend is busy with the Victron grid-tied solution. Technically - this will reduce his electrical account and provide backup power to some circuits .... needs lights for the kids to study, needs power for the home PC's for late night work, handy to keep the tv going for mommy. Price ... well Victron IS the market leader and NOT cheap. But the way he is doing it he is spreading his expenses over a period of time .... Still no way around that once off payment for the battery bank ! Regs .... uhm ja ..... doing it in accordance with engineering best practices. But without firm SA regs it remains technically illegal .... His system should be cheaper to "repair" and bring in line with the new regs once these are published. Did I mention that it is extremely frustrating to wait for our fearless leaders to get their act together ...

Neighbour has a dual approach -
- PV geyser retrofit. Personally I prefer this over a solar hot water installation, and we may well go this route later this year. price wise this cost the same as a proper pumped indirect solar hot water installation. Down side is that you need a larger panel size on your roof for the PV solution. The upside is that the panel CAN be 10 or 20m away from the geyser, for ME this is important as I dont have a usable roof space near my geyser. The main benefit is that with PV you dont have the over heating issues in the panel once the geyser is up to temperature ....
- his independant lighting solution as described above. (PS - in previous posts I mentioned that he powered his battery from the geyser panels once the water was up to temperature ..... the current equipment supplies too much charging current to the battery .... sure this will be solved in time, for NOW - NOT the route to go)

Having learnt so much from friends, I also put some money on the table -
- PV driven pool pump. I opted for the Grundfoss PoolFlex pump. This setup will now cost you just over R20k. It WORKS, well it works 98% ..... With the current overcast weather in the Cape, classic winter weather, the pump IS strong enough for the Creepy. It provides the correct daily circulation, BUT the flow is "just" too slow for the chlorinator ..... When the sun pops through the red led goes off and it does its thing, until the next cloud moves in front of the sun .... I need to get a testing kit to see the weekly and monthly impact of this. I may (should) well just up the chlorinating unit from low to medium or even to high.

Meinhard at Geyserwise GOODWOOD has just finished a two year in-situe testing of a number of PV powered pool pumps. I do believe his solution will be more cost effective than the Grundfoss .... but it is the new kid on the block ...... (Meinhard is 80% off the grid and USE PV at his own house. So he KNOWS what he talks about!)

What is MY future plans -
- PV geyser retrofit ..... seems like a 5 to 6 year payback period for us ..... I will keep you posted if we go down this road ....
- PV-battery-LED light installation, as a backup. BUT, if I go down this route it needs to have a payback period that makes sense .... only AFTER the new regs are in place.
- Right now the 1kW UPS unit seems the answer to keep us going in this interem phase until the new regs comes out ..... (being a pc ups unit it is the only option I can deduct from tax at the moment)

ChrisF · Post by **ChrisF** » Sun May 03, 2015 12:41 pm

louis fourie wrote:
ChrisF wrote:
This system wont affect the COC under the current rules - though technically the 12V circuit is not legal, not until the new regs comes into play. The nice thing here is that as long as you use the correct wire size - FOR DC !! - and standard practice for wire type and connections etc etc then this type of installation should be 99% compatible with whatever the new regs throw our way ....

Chris

What is the correct wire size?

Louis certainly not an easy question - and may well show why the new regs are taking some time to be completed .... with multiple options the powers that be must decide on the new stanards (not just regs but industry standards for SA)

What impacts on the "wire size" ....

The wiring regs is our guide -

: DSCN2232 (Small).JPG (36.47 KiB) Viewed 18477 times

First and foremost - at what current would a wire "melt" due to the current flowing through it ? Even this simple question is heavily loaded ! We are NOT talking about the "fuse" rating of the wire. Rather the idea at play is that if a circuit is left on for a few HOURS, and the wire is enclosed in some tubing (thus the heat cant really escape), thus the heat builds up over time and a safe starting point needs to be found ... Yes, the tables actually do account for wires that are "enclosed" vs wires run in open trays, it even has a different column for wires encased in concrete.

Thus we get tables for the "current carrying capacity" of wires. These tables are further sub divided into tables dealing with "single-core" wires and different tables for "multi-core" wires.

However, the wire size and the actual load cause a voltage drop in a wire. As such another calculation needs to made to check that the actual voltage drop does not exceed the allowable voltage drop of 5%.

: DSCN2233 (Small).JPG (44.59 KiB) Viewed 18477 times

With normal house wiring this has been made a LOT easier !

Standard light circuits have a 10A circuit breaker (CB), thus we KNOW the maximum current is limited. Thus a 1,5mm2 wire is used for lights and everybody is happy. :) This applies to 220V circuits !!!!!!!!!

A 12W LED set of lights will draw a few milli-amps when powered by 220V. Now connect this to a 12V supply - - - - OOOOPS !! Suddenly ONE light set draws 1A !!!!! You can EASILY use 10A for lights in ONE large room !!!!!!!!!!!

And most people still use fuses when doing a DC installation. So mommy wants more light over the kitchen, aag, just up the size of the fuse and everybody is happy .... except that overloaded wire supplying the light circuit !

So what is the answer to your question ?

NOT an easy question !!

Some of us live in a small 65m2 town house .... others have larger challet in their back yard ....

One NEEDS to understand the size of the site, and MOM's "needs" before even attempting to answer this question.

With REASONABLE wire lengths (normal home size) we may well end with MULTIPLE wire circuits, each having a DC CB of 10A and 1,5mm2.

But until the new regs are published I would use no less than 2mm2 per 10A circuit.

Would be most interesting to see if the new regs allow the use of fuses in a home .... to protect the typical home owner we may well see the new regs insisting on a second DC DB board with DC CB's.

spare a thought for the guys working on the new regs .... SO many options !! Yet they need to pen the way forward that is both practical AND safe .......

tyd dat hulle harde besluite maak en die nuwe reel publiseer !!!!

ChrisF · Post by **ChrisF** » Sun May 03, 2015 12:57 pm

louis fourie wrote:In dieselfde lyn wat Wayne dink

Baie binnekort (wag net nog vir oordrag) gaan die 3 fase transformer my R1200 per maand kos en dan het ek nog nie eers 1W se krag gebruik nie . My krag verbruik by my vorige huis, 9 maande terug, was 'n R1000 per maand.

1) Ek het lig nodig

2) Ek het reeds 'n A+++ Bosch yskas en dink daaraan om 'n A+++ vrieskas ook te kry.

3) Rekenaar (laptop) en printer (3 ure per dag)

4) TV en DVD speler (2 ure per dag)

'n 5 KW/h genie moet dan

a) Die wasmasjien (3 keer per week)

b) so nou en dan 'n strykyster

c) my sweismasjien

d) boorgat pomp vir nou (sal oorskakel solar toe op 'n later stadium) trek

Stoof is op gas, en gas geysers (Sal vervang word met solar ook op 'n later stadium)

My vrae:

i) Hoeveel batterye het ek nodig vir no. 1 tot 4 hierbo, ± watse groote inverter, en hoeveel sonpanele?
ii) sal so 'n "setup" kan werk?

Louise THIS is the type of installation that has created a market for PV installers in SA - those where the base charge is plain absurd ......

Speak to the guys at companies such as:
Solareff - http://www.solareff.co.za/" onclick="window.open(this.href);return false;
MicroCare - http://microcare.co.za/" onclick="window.open(this.href);return false;

MicroCare use their own equipment, actually manufactured in PE.
Solareff use Schneider products.

I am not sure who are the Victron installers ....

They will (SHOULD) then go through your usage with you. Next step is to then use something like the sites below to determine the number of panels you need to provide you with the kW.h you require ... the problem here is that during peak summer you may get near 6 sun hours per day (6 hours providing the max power per panel), winter time this could drop to 4 sun hours. If you want to go OFF grid you must then use the 4 hour figure = $$$$$. If the idea is to be grid tied and to reduce your unit costs then the city dweller works with the 6 hours figure - but this makes no sense if you want to get rid of that absurd base charge fee.

http://re.jrc.ec.europa.eu/pvgis/" onclick="window.open(this.href);return false;
http://re.jrc.ec.europa.eu/pvgis/apps4/ ... map=africa" onclick="window.open(this.href);return false;

The more cost effective real world solution is to work with a 5 or 5,5 hour figure AND to add a generator that can supplement your power as needed .....

the real costs will be your battery bank !!!!!!!!!!!!!!! 50 to 100k .....

you may well want to investigate "wind generators". The problem here is that these units overspeed in our winds .... the over voltage then damage the electronic components downstream ..... MicroCare has actually removed these from their price lists. They have suffered losses due to cheap wind generators over speeding and damaging their equipment ....

KOBUSL · Post by **KOBUSL** » Sun May 03, 2015 8:55 pm

Andy,
Onthou, om grid tied in te sit moet jy by die inverter se spesifikasies kyk wat is die minimum volts wat hy nodig het om te begin werk. Jy sal so ongeveer 150 v van die panele moet kry ( hulle verskil, maar dis in die omgewing. ) Dis een van die nadele as dit by kostes kom, jy moet genoeg panele opsit. Daarvandaan kan jy net bylas, die inveters het 'n taamlike wye volt spesifikasie. ( Se tot 500 v ).

Om meer krag terug te sit kan jy, as jou inverter kan, nog 'n string panele bylas, ens.

Chris, in my Sunny Boy se boekie gee hulle al die draad diktes en afstande aan, en ek glo die ouens wil aan die veilige kant bly. Ons het dit gebruik, geen probleme sover. Dit lyk my net dis baie nodig om genoeg isolators in die sisteem te he, 4 of 5 panele kan al klaar taamlik skade doen en jou die ritteltits gee as dit jou byt.

Op die oomblik is ek die minste gepla oor die munsipaal : hier by ons is totale onkunde. Wat ek wel gaan doen is om my versekering hier te kry, dis immers hulle wat moet betaal as daar probleme kom. Die grap gaan wees as hulle iemand stuur om die inspeksie te kom doen : watter reels gaan hy gebruik ? Net so terloops, al my bedrading is deur 'n man met papiere gedoen. Wettig ? Ons weet nie. Veilig : verseker.

KOBUSL · Post by **KOBUSL** » Sun May 03, 2015 8:56 pm

Vergeet om te noem : Current Automation en Exsolar doen Victron.

Post by **Mud Dog** » Mon May 04, 2015 12:55 am

KOBUSL wrote:Andy,
Onthou, om grid tied in te sit moet jy by die inverter se spesifikasies kyk wat is die minimum volts wat hy nodig het om te begin werk. Jy sal so ongeveer 150 v van die panele moet kry ( hulle verskil, maar dis in die omgewing. ) Dis een van die nadele as dit by kostes kom, jy moet genoeg panele opsit. Daarvandaan kan jy net bylas, die inveters het 'n taamlike wye volt spesifikasie. ( Se tot 500 v ).

Om meer krag terug te sit kan jy, as jou inverter kan, nog 'n string panele bylas, ens. ..........

Ek het reeds 4 paneele maar hulle word gebruik soos bo gesê. Die plan was om nog vier by te sit vir die grid-tied inverter storie, maar glo nie 4 paneele sal 150V kan opwek nie.

ChrisF · Post by **ChrisF** » Mon May 04, 2015 1:56 pm

Mud Dog wrote:
KOBUSL wrote:Andy,
Onthou, om grid tied in te sit moet jy by die inverter se spesifikasies kyk wat is die minimum volts wat hy nodig het om te begin werk. Jy sal so ongeveer 150 v van die panele moet kry ( hulle verskil, maar dis in die omgewing. ) Dis een van die nadele as dit by kostes kom, jy moet genoeg panele opsit. Daarvandaan kan jy net bylas, die inveters het 'n taamlike wye volt spesifikasie. ( Se tot 500 v ).

Om meer krag terug te sit kan jy, as jou inverter kan, nog 'n string panele bylas, ens. ..........
Ek het reeds 4 paneele maar hulle word gebruik soos bo gesê. Die plan was om nog vier by te sit vir die grid-tied inverter storie, maar glo nie 4 paneele sal 150V kan opwek nie.

hang af van die tipe panele ....

vir my swembad pomp gebruik ek "HV" panele van SolairDirect. Lyk net soos ons kamp panele, tot jy daai spec-sheet lees .... 44Voc, 36,6V werkend PER PANEEL ....

maar nou so stukkie raad wat ek op daai MicroCare kurses geleer het - die beste is wanneer jou paneel tot battery bank volts 4:1 is, dus 24V batterye so 100V van die panele, of dan 48V battery bank soek so 200V van die panele. Met die ratio is die MPPT op sy gelukkigste.

Post by **Mud Dog** » Mon May 04, 2015 7:02 pm

That means I'll have to connect the panels in series (I have them in parallel at the moment) ..... is this a problem?

ChrisF · Post by **ChrisF** » Tue May 05, 2015 7:50 am

My pool pump panels are all in series - because the motor requires the higher voltage, and to keep the current low.

For most larger installations we end up with some combination of series and parallel - again to ensure the optimal voltage to compliment your battery bank.

EDIT - your battery bank voltage is linked/sized in accordance with the power you want from the system. This also means that the inverter/MPPT charger is selected to suit this power requirement. It is the MPPT Regulator which then dictates the optimal PV voltage (series and parallel combinations) for the specific system.

KOBUSL · Post by **KOBUSL** » Tue May 05, 2015 11:09 am

Mud Dog wrote:That means I'll have to connect the panels in series (I have them in parallel at the moment) ..... is this a problem?

Andy, the big panels got a male and female plug fitted, me think they are meant to be in series.

Chris, vertel asb meer van die panele wat jy gebruik.

ChrisF · Post by **ChrisF** » Tue May 05, 2015 2:33 pm

KOBUSL wrote:
Mud Dog wrote:That means I'll have to connect the panels in series (I have them in parallel at the moment) ..... is this a problem?
Andy, the big panels got a male and female plug fitted, me think they are meant to be in series.

Chris, vertel asb meer van die panele wat jy gebruik.

If you look quickly it looks exactly like the panel we used for Project Ranger .... BUT, look a bit closer and you see this is an "HV" panel -

: DSCN1993 (Small).JPG (38.45 KiB) Viewed 18422 times

Note the high panel voltages !

I now have five of these in series for my Grundfoss pump -

: DSCN2103 (Small).JPG (47.84 KiB) Viewed 18422 times

I can now manually select if the pump runs from Eskom or from the PV panels. :)

: DSCN2095 (Small).JPG (38.87 KiB) Viewed 18422 times

KOBUSL · Post by **KOBUSL** » Thu May 07, 2015 11:11 am

Dankie.

ChrisF · Post by **ChrisF** » Thu May 07, 2015 1:19 pm

KOBUSL wrote:Dankie.

gesels gerus met SCOT by MicroCare. Hulle doen redelik roadshows om seker te maak potensiele kliente en installeerders kry die regte inligting.

beste twee dae wat jy ooit sal spandeer.

ons 4x4-PV ervarings is net genoeg om ons deurmekaar te maak vir die groot stelsels ....

ChrisF · Post by **ChrisF** » Sat May 09, 2015 5:30 pm

State of eskom in SA .....

two weeks back we had load shedding FOUR nights in one week.

This week we had load shedding starting halfway through the wifes cooking .... okay, we could get out the camping gear and finished cooking on two gas tops.

Today, jip Saturday morning, my neighbour sent out a team of workers to go and try to catch up on a site running late due to load shedding - at over time rates - the load shed started just after they got to site .....

Our secretary had the "benefit" of three nights of load shedding this past week - this with a daughter in varsity that should now be studying for the June exams.

sometimes a load shed is a blessing in disguise and we can actually talk to family members. but I am wondering about what is waiting for this winter ..... or will it all again magically sort itself out the day after eskom gets its extra increase .....

o-well, time to put all my research to work and to pull a plan from the hat and to DO something ..... What it OUR options ? Well it relates to the individual families "needs", be it perceived or real needs ...AND ... the budget available to through towards some mystical solution.

NEEDS (be it perceived or real) -

- cooking food .... the odd take away is nice, but certainly this is neither good for the wallet nor the figure in the long run. So gas hob is certainly on the cards .... just need to get my wife to think along these lines. Seems the going rate for a hob and installation is in the order of R 4 500 to R 6 000.

- TV / computer - I have a laptop at home and dont need much power for a PC during a load shed. Our tv setup draws about 15A from the battery, thus 15x2=30Ah for a typical load shed. This is perfectly inside the safe operating curve of a deep cycle, ie not taking it below 50% SOC.

- Light - initially I enjoyed the camp feel of a load shed and one or two camping lights on in the house .... some NEED proper light to study at. With winter setting in and our load shedding now impacting on what I can actually get done after hours I am now looking at an extra 12V light circuit for our house. The way I am thinking I want to use about 15W in each of four zones, with no more than 2 zones working for the full load shed. Thus a meager 5A.h for a load shed, or hardly 10A.h if we used two 12V light circuits for most of the night. Thus the deep cycle battery can deliver in our needs for both load shedding and to use the lights most of the time.

using a 100W PV panel, the battery should recharge fully each day. I can also use the Benton charger on a 24/7 timer to ensure the battery is fully charged on a regular basis .....

okay, back on topic ....

- Fridges / freezers - FIRSTLY, a fridge or freezer is perfectly insulated that a 2 hour load shed is non-issue. But if you truly want to run your fridges of a battery bank .... THIS takes the game into a totally different price field !! Due to the starting amps of a single fridge you are now looking at a MUCH larger inverter. However, due to the current draw you will now start looking at a bank of batteries ... it is just the start of a very expensive snow ball .....

- Washing machine - dont even go there !!!!! Now you are in the realm of the 150k + installations

The punch line is - you CAN make a load shed much more bearable for less than 10k ...... OR you will need more than R100k to take that next step.

ChrisF · Post by **ChrisF** » Sat May 09, 2015 6:05 pm

And thus the time came to make a decision .....

Well the budget helped .... with the 100k solutions not an option I considered my "cheaper" options.

1) I am partial to a fully automatic solution. This would be something like the MicroCare 1kW UPS unit for about 10k ... except they dont get back to us with a final price or availability

Current Automation has a similar setup from Victron. But is closer to a component approach, which means you would still have to buy the batteries and a few items to make up the UPS .... Very limited stock arrived and are being pre-sold and then sent to the shop nearest where the client paid for it. At least there is "some stock" .....

Try to get information from EXSolar and this is what you get -

: exsolar (Small).png (220.06 KiB) Viewed 18413 times

What I thought was going to be a buying spree turned into a serious hunting exercise ......

And the option of a UPS does not really address the issue of backup lighting.

2) So I gradually started making peace with the system proposed but a reputable UPS supplier. Basically his advise comes down to:
- size the batteries to YOUR needs, to ENSURE you wont drain in past 50% SOC. I made the call to limit this sytem to ONE battery, for the tv and lights only. THIS guided my choises on other the other components.
- get the best possible charger !! QUALITY, not high charge rate. I believe the 7A of the Benton BX 2 is perfectly suited to this task. But I took it one step further and got a 100W solar panel to use with a MPPT regulator I already had (from no less than MicroCare :) ) The Benton will be on a 24/7 timer so that it is only on for maybe one hour per day (exact time to be checked once the sytem is in operation).
- my friend recommended the 300W inverter from Victron, enough power for my tv, brilliant wave quality, and the unit is as rugged as they come ... but he did mention that he has been waiting for nearly a year for his third unit. Simply NO STOCK ! I settled on the Mean Well 400W unit. Mean Well is a French company that provides a range of quality electronic products, manufacturing in Taiwan. Even with this unit it is only Current Automation that has limited stock.
PS - IF I wanted to use more power than what one battery could deliver I would have gone for a battery bank, and then the inverter would have been such that I would have opted for the 4x4Direct inverter. At the moment our test unit is powering my neighbours garage door.

This system does mean I had to compromise on my desire for a fully automatic system .... I know it is technically possible rig up contactors to achieve an automatic system, but then my extention lead becomes a permanent fixture exceeding the Regs. Small infraction, but I am really trying to keep this as legal as possible.

Our system is now planned to be a mannual switch on, roll out the lead, and plug in the tv. The lighting circuit will be a permanent second circuit, to best practice, and I can then amend if needed once the new Regs comes into play.

All the components, except the lighting items, are in the garage and I am now playing puzzly games to figure out the layout and a few logistics ...... And my mind is racing thinking about all the various options. Got some nice ideas for the lighting .... Now waiting for my neighbour to pop over to comment on the Regs and legalities of the next few steps ..... tonight I am screwing everything together, en more trek ek draad ....

promise I will post pics and more details as the project unfolds .... thanks to our trusty 4x4Direct the system will have a space-age monitoring heads up display !!

Willem01 · Post by **Willem01** » Sat May 09, 2015 6:20 pm

I'll be watching this space

ChrisF · Post by **ChrisF** » Sun May 10, 2015 4:51 pm

the joys of projects ... and the frustrations that is so much part of it .....

14:00 the red lights goes and the F1 starts .... at the same second eskom believes our area needs a load shed.

The small UPS keeps the tv going while I watch the antics of the first 2 laps. Now to get 220V power to the small UPS before it dies.

I run a lead to link the battery to the new inverter setup - parts are in process and not yet mounted in place. The battery was FULLY charged yesterday, resting voltage of 12,8 V. Few seconds and the inverter pulls it down to 12,2V and kicks out on its safety setting ....

now to start searching for the cause ....

can hardly believe a 15A load can pull down a battery THAT quickly.

losses on my home-made connector bars at each battery pole ??

heaven forbid my brand new battery is a dud ..... ??

o-well, will borrow my neighbours 2-week old deep cycle and check the inverter to load part first .....

I would really appreciate input from those that have gone down this road before.

Am I heading for a parallel battery bank to ensure the voltage stays high enough for the two hours ?

ChrisF · Post by **ChrisF** » Sun May 10, 2015 7:37 pm

okay ..... update

made new copper extensions at the top of the battery, ie better connection.

Rigged up the parts on the desk, without the extra 2m extension to the battery.

connected the tv and busy testing the system.

Battery volts fell from 12,7 down to 12,18V, in about 25 seconds.

At this point the current draw was near 25A - way more than the running amps of the tv .... think the small ups sucks up amps at the start for its own charging circuit .....

About 60 seconds later the current started dropping to 18,5A (which is about what the tv requires), and the volts steadily climbed to 12,23V.

20 minutes later and the volts is still 12,23V, and the current remains constant.

now for the rest of the 120 minute test .... :)

PS - looking for some info on the "C" value of a battery. This unit is rated 102Ah at "C5", and 81Ah at "C20" .....

KOBUSL · Post by **KOBUSL** » Sun May 10, 2015 8:06 pm

Volg met aaaaandag.................

ChrisF · Post by **ChrisF** » Sun May 10, 2015 8:26 pm

1 hour 15 minutes and going .... :)

but this has raised some battery questions that I would like more info on ....

ChrisF · Post by **ChrisF** » Sun May 10, 2015 9:52 pm

short recap of the test, and readings taken during the test.

At 19:10 I switched the tv to the inverter and started logging the data.

The first few minutes was a bit worrying ...

The volts dropped from 12,7V down to 12,18V in a manner of seconds.

During the next 1 or 2 minutes the volts slowly recovered to 12,23V, briefly rising to 12,25V.

I logged the volts during the 2 hour test, here are the 30 minute readings:

19:40 - 12,21 V
20:10 - 12,17 V
20:40 - 12,11 V
21:10 - 11,99 V

I switched the tv back to mains power, and left the inverter on idling volts, now monitoring the recovery volts - remember it is the resting volts that are a measure of the SOC of the battery.

21:12 - 12,26 V
21:15 - 12,29 V
21:20 - 12,31 V
21:45 - 12,38 V

Now bear in mind the experts say the resting voltage should be taken between one and two hours after removing the load, as this is the most accurate measure of the SOC (net te laat om nou nog 90 minute wag vir die finale lesing)

mathematically I used about 36A.h from the battery, ie accounting for losses a SOC of 60 to 70% should be in the ball park, with the battery having been fully charged at the start of the test. The 35 minute reading seemed to be closer to a 75% SOC - ties in with the slightly positive results one would expect from a brand new and fully charged battery.

: 7.jpg (33.5 KiB) Viewed 18375 times

seems in the right ball park ...

Okay so the first run was a BUST !

Second run seems VERY positive :)

Now to wrap up a few loose bits, and then to start testing the system over a number of load sheds .....

already connected the Benton BX 2 to recharge the battery.

PS - the Benton BX 2 is seeing the battery as just under 50% SOC. It charged for about 20 minutes before switching to the third charging level, ie 50 to 75% SOC. Ideally one would need to now monitor the charge current and time to confirm the ACTUAL SOC.

Riaan99 · Post by **Riaan99** » Mon May 11, 2015 4:37 pm

Kêrels, ja ek weet dis "Made in China", maar alles kom van daar af....kyk bietjie hierdie link:

http://pocasa.en.made-in-china.com/prod ... erter.html" onclick="window.open(this.href);return false;

Dit is darem rerig nie te duur vir die masjien nie, met 'n 2 jaar waarborg is dit amper die geldjies werd om te probeer...of hoe....?

..ek wonder of die invoerbelasting ook 16% gaan wees...?