From 6 6 volt batteries to 6 12 volt batteries

[etdiego]

I looked a bunch of places but I cant find anything on this. I am cleaning up a cart I got a great deal on. It is a 36 volt cart and I had a thought for a little longer run time. I measured the space and I can fit 6 12volt batteries. Configured with 3 in series, then the other 3 in series and then those two sets in parallel. Any Ideas on the effects on the charger or the motor? It just surprises me that it seems like no one has ideas on this. Opinions are very welcome. Hard calculations or facts are greatly taken into account. Thanks.

[sportcoupe]

I've had 36, 12v batteries under the seat in a ezgo txt. It depends on what type 12v battery you are referring to.

Oh, and welcome to the forum!

[JohnnieB]

If you are thinking about using 12V car batteries, it won't have much run-time and the batteries won't live very long. If you are thinking about 12V deep-cycle batteries, they are about 2" longer than 6V deep-cycle batteries and they won't fit in the stock battery frame.

36V is 36V, so if you can shoehorn them under the seat and connect them in series/parallel as stated, the motor and controller won't know the difference. The 36V charger will also work, but may take longer to charge the pack due to the higher storage capacity.

The standard 36V pack has 225AH and using six 12V deep-cycle batteries you can build a 36V pack anywhere from about 280AH up to around 310AH.


It will still be a 36V cart, so speed and performance will be the same, less losses from the fact it will about 120 pounds heavier. The only gain will be longer run-time.

[sportcoupe]

Here's my 6-12v Trojan T-1275's under the seat of a txt and between the frame rails. If I were to series parallel them for 36v I would have a 450AH pack

Having a pack that large would take forever to charge, I don't even want to try and calculate that. It would run a very, very, very long time though.

[sportcoupe]

For comparison, here's 36-12v batteries under the seat.

[JohnnieB]

Originally Posted by sportcoupe

Here's my 6-12v Trojan T-1275's under the seat of a txt and between the frame rails. If I were to series parallel them for 36v I would have a 450AH pack

Having a pack that large would take forever to charge, I don't even want to try and calculate that. It would run a very, very, very long time though.

Voltage add when in series, AH stays the same.
AH add when in parallel, Voltage stays the same.
A T-1275 is a 12V 150AH battery, so with six of them, you can build the following battery packs:
12V 900AH
24V 450AH
36V 300AH
72V 150AH

Each of the four pack arrangements would have a total storage capacity of 11.4588 kWh, so the range would be roughly the same for all four.

The higher the pack voltage, the more efficiently the cart operates, so the 72V pack will have the greatest range potential of the four.

[sportcoupe]

My bad, it is 300ah @ 36v. Still that's a lot of ah.

[kgsc]

Just a thought, I realize that adding batteries will help in run time but adding the extra weight will take some of that away. At some point is it worth it?

[JohnnieB]

Originally Posted by kgsc

Just a thought, I realize that adding batteries will help in run time but adding the extra weight will take some of that away. At some point is it worth it?

I suspect, for most people, the fiscal point of diminishing return occurs long before the physical point of diminishing return is reached.

[tdump]

I am no expert at this and wont try to pass my self off as 1.
But I will just explain my recent experience with this.
My 91 Marathon 3 wheel needed battery's.The Pacer 6 volts were 8 years old and my dad uses it a good bit and it was not holding up long anymore.
He had talked to a fellow that changes out battery's for computer memory banks and sells the pull outs for 30 dollars apiece.they are usually 2 years old and Adsorbed glass mat battery's.
I pulled the 6 6 volts and installed 6 12 volts of same size of these in the cart.Wired as needed.
The man says,these batterys are equal to 1000 cranking amp? Who knows really.
But When my dad backed it out of the shop and put it in forward and floored it,the front wheel barely left the ground and his eyes got big as saucers.
2 months so far and no problem.We charge it a bit more often as these batterys are not designed to run way down and be left that way.
There is no change in top speed that i notice,but you get to it much quicker and hills seem easyer to pull.
I have a set in my 77 project and will be useing these as time goes by in my other 2 carts as well.