Author Topic: Batteries for a new system help please!  (Read 3182 times)

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tnhomestead1

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Batteries for a new system help please!
« on: March 30, 2015, 12:15:40 PM »
Ok had a 12 volt system in the old house. We tore it down, now going to a 24 volt system. Have 1360 watts(24v) flex panels for the roof, and about 800 watts(12v) from the old system. Went to a Outback charger, and a Magnum Inverter. The old system had 10 golf cart batteries, for about 1000 amp hours. So with it being 24 volt now, do I need to have 2000 amp hours? 1000? or 500? I would think I would need less batteries, not more but not sure! Been so long since I was on here last, had to create a new account! LOL Thanks for any advice and help folks!

TDC

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Re: Batteries for a new system help please!
« Reply #1 on: March 30, 2015, 01:21:09 PM »
You could use the same batteries, just connect them for a 24v bank rather than 12v. 

Flux

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Re: Batteries for a new system help please!
« Reply #2 on: March 30, 2015, 05:30:21 PM »
Depends on the batteries, If they are 6v then 10 batteries doesn't work for 24v

For the same energy storage you need half the AH rating at 24v compared with 12v but using similar batteries it will come to the same number as you need to double the voltage.

The cable size will be less for the same loss at 24v as your amps will be less.

Flux

tnhomestead1

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Re: Batteries for a new system help please!
« Reply #3 on: March 30, 2015, 11:49:18 PM »
Cant use the same batteries, they were stolen -- along with the inverter. Thats why I was wondering about the battery size, so 500 amp hours at 24 volts should be the same as 1000 amp hours at 12. Soo, thanks for the help, now to find a good source of batteries!
Tried Trojan today, one shop had no brains, 1 no phone and 1 said we dont sell them and not sure why we are listed as distributors! LOL Guess its time to head to sames club for some golf cart batteries!

madlabs

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Re: Batteries for a new system help please!
« Reply #4 on: April 01, 2015, 03:28:20 PM »
For what it's worth, I've done very well with sam's batteries. I live off grid. For the first 6 1/2 years I had a 12V system with 10 sam's batteries. The last fall I switched to 48V, so I took 6 batteries from my golf cart and married them to the old batteries to make a 16 battery 48V bank. They went through the winter fine and I imagine I still have a couple of years in them.

I do charge every day though, either sun or with the genny. I do a bulk charge only with the genny. I try to keep my SOC 75% or better, but they have taken some hots along the way. Especially in the first few years when I didn't have much solar.

IMHO, cheap batteries can work out if you don't deep cycle them too hard. Or at least they sure have for me.

JOnathan

TDC

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Re: Batteries for a new system help please!
« Reply #5 on: April 02, 2015, 07:31:12 PM »
What brand of batterys did you buy at sam's?