2 x 6V batteries

[Alerider]

upgrading from my standard 12V to 2 x 6V batteries is my next project.
Trojan T105s have 225 amp hrs each. will 2 T105s wired in series give me 450 amp hours?

[stateboy]

I would say yes. I've read multiple threads in the past couple years here on people jumping over from a 12 volt to two 6 volts to increase their amp hours. Unless someone chimes in differently, I'd say you're good to go with 450 amp hours.

[Alerider]

thanks. it seems too good to be true that a 6V battery would have so much more capacity than a similarly sized 12V.

[Bullitt6283]

Changing from one 12 volt battery to two 6 volt batteries in series increases the amp-hours because the cells in the 6 volt batteries are typically physically much larger than the cells in the 12 volt batteries.
12 volt batteries have 6 cells, while 6 volt batteries have 3 cells, in roughly the same sized case.


Two 6 volt batteries wired in series gives you 12 volts. But it does NOT double the amp-hours.


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[RVermont]

2 6 vdc 220 amp batteries will give you 220 amp hours at 12 vdc. Of which 110 is truely useable as you only want to draw down to 50%.

[Alerider]

doubling the voltage is something my peabrain can understand but why doesn't the amp hour capacity increase?

[Bullitt6283]

Originally Posted by Alerider

doubling the voltage is something my peabrain can understand but why doesn't the amp hour capacity increase?

Each cell can supply a fixed number of amps for a fixed number of hours. Stacking several cells in series does not change what each cell can do.


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[Bookemdanno]

Originally Posted by Alerider

upgrading from my standard 12V to 2 x 6V batteries is my next project.

Trojan T105s have 225 amp hrs each. will 2 T105s wired in series give me 450 amp hours?

If you want the 450 amp hours you’ll need 4 x 6V batteries. 2 sets in series to make 12V and then you’ll need to run those 2 sets in parallel. Hopefully that made sense.

[Siamese]

225 amp hours is still pretty good, and of course, a golf car battery is more robust than the typical 12v "deep cycle" battery.

[Alerider]

thanks to all of you. I'll go for the upgrade.

[RoyBraddy]

Here is a simplified diagram with two 6V 220AH GC2 Golf cart batteries wired in series...



Connecting a second group of two 6V 220AH Batteries will give you 12V at 440AHs...

Consider the 6V batteries a 12V Battery haha... If you only have two 6V batteries and one goes dead on you, you will not have the 12V you need to operate your setup...

Having two groups of 6V batteries in series would be like having two 12V batteries in parallel...

The T105s have great reviews and are somewhat high dollar... I am currently building up two groups of two 6V 215AH Duracell batteries wired in series to go on the tongue of my OFF-ROAD POPUP trailer... You can pick these up at BATTERY PLUS stores for around $90 each... This is going to give 440 AH capacity when I am done...

Mine will be mounted inside one of those TORKLIFT Battery boxes with slide off lid. I will have a small 10WATT SOLAR panel on each side one for each 6V battery groups. This will provide small trickle charge for both sides of my battery bank...

Will look something like this

Google image

This will fit perfect inside the two welded on mounting angles replacing my three 85AH 12V Interstate batteries...

Roy's image

Roy Ken

[Danno]

Originally Posted by RoyBraddy

This will fit perfect inside the two welded on mounting angles replacing my three 85AH 12V Interstate batteries...

Don't forget venting. Also, if that box is made from steel or aluminum, it's not going to last very long. Most industrial 6volt batteries are not sealed.

[Alerider]

My battery box is steel, under my middle step into the coach. The current, single battery sits on 2 steel rails welded to the box bottom and the box is vented to the wide-open bottom. Is that enough ventilation?

I've discovered the box height isn't sufficient for taller golf cart batteries and am considering modifying the rail system to be lower for 2 future batteries.