What is better or supply power longer? Two(2) six(6) volt batteries wired in series or two(2) twelve(12) volt batteries wired in series? I am debating which way to go for the longest lasting power as we will be doing alot of primitive camping and I need to run my sleep machine all night. I will have a generator to run in the day to recharge the batteries when needed. Thanks in advance for all of your comments.

Dont wire 2 12v in series.The 6s in series are best for deep cycle.Bill

The 6 volters wired in SERIES will give better service then 2 12 volters in parallel.Of course this is based on standard group 24 or 27 batteries.

Starting and most 12V batteries have six 2V cells wired in series. To fit six cells in the space of the battery housing, the plates have to be somewhat thin. This gives a lot of surface area relative to the volume of the battery. Surface area = high amps.This also gives each lead plate less volume relative to its surface area.Volume = length of discharge over time, so the 12V has shorter discharge time.The 6V has only 3 cells in the entire battery housing. It can have really thick plates (which most deep cycle/golf cart batteries have). Lower surface area = lower amps, but much, much longer discharge time.(You therefore have to put two 6V batteries in series to get 12V. You don't add amps in series, so two 225Ah batteries in series gives you 12V at the same 225Ah.)

I am assuming you meant to say two 6VDC Batteries in series and two 12VDC batteries in parallel... Consider these pictorialsTypical wiring for both battery groupsTwo 6VDC batteries in SERIES - Connecting two in series doubles the OUTPUT DC OUTPUT VOLTAGE - The RESERVE POWER will only be the same as ONE 6VDC Battery.Two 12VDC Batteries in PARALLEL - Connecting the two in PARALLEL keeps the same DC OUTPUT VOL:TAGE - The RESERVE POWER will be doubled connecting these in parallelIt really comes down to cost. 6VDC 220AH batteries can be purchased from COSTCO/SAM CLUB for around $80 each. The Reserve Power for this battery is typically 440 minutes (7.3 Hours) meaning this group setup should produce 12VDC @25AMPS for around 3.6HR before dropping to 50% charge state. The cost of 12VDC 220AH batteries is not going to be cheap. You can get a 12VDC 85AH Battery for around $80 most anywhere. The RESERVE POWER for a 12VDC 85AH battery is 140 minutes (2.3 Hours) meaning this battery group will only produce 12VDC @25 amps for around 1 hour before dropping to 50% state of charge. Having two in parallel will increase this to around 2 hours of time. Hope this helps deciding which is better for you.Roy Ken

Hi,There are lots of myths about six volt vs twelve volt. What matters most is total capacity in amp-hours.Wiring needs to be properly balanced for the battery bank.

6 volt vs 12 volt | Good Sam Community

23 Replies

mthockeydad
Explorer
May 07, 2014
Starting and most 12V batteries have six 2V cells wired in series. To fit six cells in the space of the battery housing, the plates have to be somewhat thin. This gives a lot of surface area relative to the volume of the battery. Surface area = high amps.
This also gives each lead plate less volume relative to its surface area.
Volume = length of discharge over time, so the 12V has shorter discharge time.

The 6V has only 3 cells in the entire battery housing. It can have really thick plates (which most deep cycle/golf cart batteries have). Lower surface area = lower amps, but much, much longer discharge time.

(You therefore have to put two 6V batteries in series to get 12V. You don't add amps in series, so two 225Ah batteries in series gives you 12V at the same 225Ah.)
enblethen
Nomad
May 07, 2014
The 6 volters wired in SERIES will give better service then 2 12 volters in parallel.
Of course this is based on standard group 24 or 27 batteries.
P3TC
Explorer
May 07, 2014
Dont wire 2 12v in series.

The 6s in series are best for deep cycle.

Bill

Forum Discussion

6 volt vs 12 volt

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