Amp hours

[Mainstreet]

I have 6 6V lead acid batteries wired in series parallel to produce 12VDC. Each battery has an amphour rating of 210 amphours my question is, are the amphour capabilities for each battery in the circuit additive? In other words, is the total amphour rating for the bank 6X210 = 1200+ amp hours? Or, rather is the rating for the bank, due to the series parallel circuit, 3X210 = 600+ amp-hours. I'm considering switching from AC driven refrigeration to DC so the information is critical. I have a 8kw ones generator I just had rebuilt and is working very well. I also have a a very functional solar panel system as well as dual alternators off the Perkins 4-236 one of which is a high capacity Balmar. Thanks in advance for the input!

[noelex 77]

630 AHrs @12v.

[john61ct]

Series keeps AH constant, increases voltage.

Paralleled othe way around

[ontherocks83]

Series increases voltage and parallel increases capacity. So 6 6v's is like having 3 batteries so you have nominally 630ah of capacity. If your batteries are older then that 630 will be less.

[TreblePlink]

One other thing to remember is that you will have about 300 ampere-hours at 12 volts usable - because discharging them more than 50% will shorten their life. If you gotta, you gotta, (like starting the engine) but don't plan on using more than 50% of your listed ampacity.

[StuM]

You may like to read http://www.cruisersforum.com/forums/...ml#post1933764 as a basic primer.

The best way to think about such problems is to reduce everything to Watts and Watt hours.
The Basic Rule: Watts = Amps x Volts. (So Watt hours = Amp hours x Volts)
Conversely Amps = Watts ÷ Volts (Amp hours = Watt hours ÷Volts)

Since each of your batteries has 210 Amp hours at 6 Volts, that means that each battery has 6 x 210 = 1260 Watt hours.
You have 6 batteries, so you have a total of 6 x 1260 = 7560 Watt hours.

When combined into a 12 Volt bank, those 7560 Watt hours will provide you with 7560 ÷ 12 = 630 Amp hours.