How big is your battery bank?

[David HK]

I have three battery banks.

The first is wet lead acid with two auto batteries totalling about 130 AH.

The second is SLA of about 90~ AH.

Both sets are negative connected  and the positive line is selected via a knife switch.

All 12 volts.

The system normally works with wet lead acid and I keep the SLA's for reserve.

I also have a 6 volt battery bank of SLA's.

[thunderhead]

2000Ah@12v AGM. But they are old (£250 off eBay 7 years ago) and I doubt they are full capacity anymore.

[wpowokal]

I am going to take a second bite at this one....

My new system batteries are 1600 A/h @ 100h rate Exide Eneergystore wet cells

Waiting to be installed

Installed


Supervisors were tired after all that work


Allan of the jungle

[thirteen]

Was or is this their break time or end of shift time. As a suggestion  you might put a bar in front of the batteries up about 4 in just in case one of your loborers deside to put there front hands (paws) on the batteries at some time. There are times when they really want to help. Looks nice. Just an idea to play with.
Wishing everyone a happy Fathers Day!!

[jaysicle]

210 Ah at 12V

[Madscientist267]

wpowokal -

Very nice... and that 'Danger' sign adds a subtle touch that just seems to set it in motion.

There's something about a sign to warn you (the bigger the better) that you will kill yourself if you 'screw around in here' 

One day, I'll put one up. Till then, let the damn cats figure it out for themselves. 

They're the only living things that can really get back behind the servers (besides me) to gain access to the only batteries that really pose any threat, and they can't read anyway. I'd be wasting my time.

Doesn't matter what I do, I can't keep them out of there. They like the heat in the 'hot isle' from the 'puters. 

Maybe a 'No Smoking' sign would be a nice touch, but again, no real point. I go outside to smoke, and nobody else in the house ever joins me. 

I GOT IT! How about a 'Dont flick your Bic to check electrolyte levels' sign? 

Steve

[wallablack]

what i did was figure out how much electricity i used in a 2 week period, and i doubled it for storage..i figure we have typically 3 days of sun, and 3 days of rain.....just hypothetically...i also had 80% of power coming from wind turbine(s), and 20% from solar....and no matter what i dont let the batteries go below 60% charged...the trick is to not hurt youre batteries.i had read lots prior to deciding also..there is alot to it, and many myths also....i have a battery file somewhere on here if you can find it..makes for a good read, and worth keeping...take care..pickster

http://www.otherpower.com/images/scimages/1135/battery_chapter.pdf <---From the book: “Solar Electricity” By Robert Sharman

(Attachment Link)

Are they sitiing on a concrete slab?
I had troubles with my battery bank sitting on the conrete floor, such as losing charge quickly. Then I remembered something my Physics teacher said to me 20 years ago "It's like charging your car battery on a concrete floor, it just wouldn't work". It was reunion time so I tracked him down and gave him a call. Sit them on a rubber mat or just off the ground al together and all of your problems will go away.
They did.

[Mary B]

With modern battery cases sitting on concrete doesn't make a difference unless your batteries are filthy.

I have 464AH at 24 volts fed by 1,100 watts of solar via MPPT45 charge controller.

[Frank S]

With modern battery cases sitting on concrete doesn't make a difference unless your batteries are filthy.

I have 464AH at 24 volts fed by 1,100 watts of solar via MPPT45 charge controller.
[/quote
 this is true and not true at the same time.
 Yes modern battery cases are made out of non conductive plastics where as back in the day to 6 volt cars battery cases were made out of rubber and tar the carbon content could allow discharge even before that batteries were made out of wood & glass jars the wood could absorb moisture and crack the jars
 there is now no direct electrical discharge Now there is no direct electrical discharge through the case, and batteries will have some discharge just from sitting un used no matter what they are sitting on
 But when a battery is allowed to sit directly on concrete the possibility of cold soak from the concrete is greater than when they have a mat of some other material between them and the concrete. If you have a large bank of batteries placed very close to each other and sitting on concrete keeping the sides of the cases clean and dry if almost impossible  when watering some spillage is bond to happen sooner or later dust will accumulate once an electrical circuit is established soon the batteries will start to discharge
 I always say it is cheap insurance to have the bank up off of the floor and situated so it is easy to clean the sides of the cases as well as the tops 

[Dustoffer]

Main;  780AH @ 24VDC (2012)     8- L16S
Garage/Addition;   780AH @ 12VDC (2007)  4-L16S
Earthship outbuilding;  390AH @ 12VDC (2012)  2-L16S

[TGB]

4 banks, 12v 480ah, 12v 210ah, 12v 160ah, 12v 90ah.  Cobbled up really.

[Bruce S]

Main;  780AH @ 24VDC (2012)     8- L16S
Garage/Addition;   780AH @ 12VDC (2007)  4-L16S
Earthship outbuilding;  390AH @ 12VDC (2012)  2-L16S

OKay, I'm curious about the earthship outbuilding 
Got a pic of that?

[XeonPony]

current 460Ah @ 12v

design size 920AH @ 12V

[HiddenMountain]

I guess it's been a while since I've been on here so I'd best update my battery scenario...

Like most who play with this stuff, I have slowly improved my system. I started with an old wire spool made into a pelton wheel  hooked to a mountain bike frame that ran a 12V Delco alternator. Then into a Canadian Tire marine battery and a Canadian Tire 1750W made in China inverter. Don't laugh, it worked.

I then moved up to a ES&D Stream Engine @ 12V and on up the hill into my 8 12V SLA's and a big ol Trace modified sine inverter that gave us 1800W.

Last year was the biggie. We switched the Stream Engine's innards to put out 24V then put in 4 450AH Rolls Surrette's. And a new Magnasine MS 4024 pure sine inverter.

So, the answer to the question? 4 450AH Big Red Batteries!

[larry g]

     450 ah @12 volt

[jlsoaz]

12 kWh @ 48 Volts.  A separate website tells me this is 250 Ah so that's how I filled in the poll, but note that otherwise it would not have known my Ah.

I had the system installed a few years ago and am definitely grid-tied, with an Outback smart inverter that seems to handle the decisions and activity of my solar, battery charging and discharging, grid back-and-forth, etc.  The batteries are lead, I think AGM.

[Mary B]

Now 928AH... at 24 volts...

[frackers]

Currently 1000ahr @ 24v, about to rewire for 48v to drive an Ozinverter

When these AGMs die, which may not be long as they now won't get to full float and idle voltage is 25.6v rather than the 26.1v of 4 years ago, I'll be going LiFePo at about the same size i.e. 500ahr+ @ 48v

I've pushed about 67000ahr in and 62000ahr out (92% efficiency) in the time I've had them so that equates to about 1.5megawatt-hrs of useful power. Looking forward to getting the main grid-tie solar system connected in as that has run over 20MW-hrs in less than 3 years.

[ruddycrazy]

Got 2 separate systems on the farm, 24 volt 600AH on the house and 24 volt 735AH for my shed running the machine-shop. Both batteries are ex forklift traction packs and with a good full charge we get 3 days on the house and my shed bank is never below 25 volts as that old 2hp wind genny just keeps em topped up.

[jlsoaz]

This poll is cool and a lot of people have weighed in with votes, but I think a fair number have commented that it might make more sense in kWh.

I'd like to suggest that someone set up a new poll "How big is your battery bank in kWh?".  Leaving the question first to the original poster, madlabs, to see if they would like to do it.  I'm thinking mor divisions, maybe something like:

<3 kWh
3-6 kWh
6-10 kWh
10-20 kWh
20-30 kWh
30+ kWh

but I don't know.

[DamonHD]

Then you also ought to be clear about nominal capacity or usable capacity, I think, given that for most lead-acid users the first will be about twice the second.  (Eg my 400Ah 12V bank is nominally abut 4kWh but usable about 2kWh).

For (say) LiFePO4 users and maybe NiFe the difference is less stark.

Rgds

Damon

[Bruce S]

Let's not forget NiCds, my bank of them gets used at 80%
I know these may not be the norm, but there are still very large ones around that can be for home use.
I've not heard from TomW in a long time, but his bank was nearing the 3Kw size of NiCDs and at 80% that would be around 2.4Kw.

Bruce S

[thirteen]

Hopefully in two years I'll have two banks.  New one around 1000 ah then a portable one around 400 ah. the second one will be on wheels and be used for a small cabin I wish to build in a canyon unseen unless you walk up to it. Nice view, with a small spring, no real road. I'll charge it up at the house then tow it there.  Not much for living full time but good for a week at a time. A total get away place.13

[XeonPony]

figure I'll give this a bump. Now it is 56Kw at 48V atm 32Kw is online

So, 36,000w / 48v = 750Ah online

Each module is 24V @ 375Ah, takes two modules to make 1 * 48v @ 18kwH I have 3 48V modules