Two 12V Batteries?

[lswartz]

Originally Posted by bikendan

if everyone visited the "12 volt Side of Life" website, where a lot of Herk's pics come from, there would be a lot less questions like this.

I have, but his explanation seems clearer to me & he pointed out something that I should have done, replace both 6 volt golf cart batteries at the same time vs. only the one bad one.

[DDC]

Originally Posted by bikendan

if everyone visited the "12 volt Side of Life" website, where a lot of Herk's pics come from, there would be a lot less questions like this.

But then the forum would be boring, these subjects are interesting in that you also get to know who has the knowledge about certain information, who's advice is good and who's is not so good.

[lswartz]

Originally Posted by herk7769

In order for the internal resistance to be equal:
1) The batteries must be from the same manufacturer
2) The batteries must be the same type and size
3) The batteries must be the same AGE (the same number and depth of charge/discharge cycles)
So, buy them as a set and change them out as a set.

Hmm, I did not do this. I only replaced the one bad 6 volt battery. I have used both 6 volt batteries (old in series with the new one ) for a 8 days dry camping so maybe it isn't to late to replace the old battery.

In order for the external resistance to be equal:
2) The inter connecting wires inside the cell MUST be identical in resistance. That is the SAME length, gauge, and termination (lugs).

I have a heavier gage wire connecting the two batteries in series. I think that is OK.

[Herk7769]

Originally Posted by lswartz

I have a heavier gage wire connecting the two batteries in series. I think that is OK.

Two 6 volt batteries in ONE cell (12 volts) what connects the two together does not matter so much since there is only one cell of 12 volts.

If there are TWO (or 3 like in the photo) cells (4, or 6 6 volt batteries) then what ever size you use in one cell must be the same in the other(s).

[lswartz]

Originally Posted by herk7769

Two 6 volt batteries in ONE cell (12 volts) what connects the two together does not matter so much since there is only one cell of 12 volts.

If there are TWO (or 3 like in the photo) cells (4, or 6 6 volt batteries) then what ever size you use in one cell must be the same in the other(s).

Thanks, that makes a lot of sense.

[Herk7769]

Originally Posted by herk7769

Two 6 volt batteries in ONE cell (12 volts) what connects the two together does not matter so much since there is only one cell of 12 volts.

I was reminded (in PM) that the connecting wire between the TWO 6 volt batteries "does not matter so much" PROVIDED it is the same or larger gauge than the feeds into and out of the battery bank.

Obviously if it is smaller than the wires providing the charging/discharge current it will just add unnecessary "internal" resistance to the bank with associated increased current wasted as heat.

[Borwick]

Originally Posted by lswartz

If it is cold, I'd like one too.

I am having a heck of a time finding a container for my 2 6 volt golf cart batteries (& yes, you get 12 volts with the amp hours of the weakest battery). The Walmart battery boxes are not high enough for golf cart batteries. the same for their tool boxes. I am going to try a Rubber Maid box tomorrow & then visit Lowes and/or Home Depot. Maybe Sears as well. I may just have to find someone to weld some new angle iron on top of the hitch to give me some more space.

I found this box online. Although it's designed for marine use, it has worked fine now for several years on the tongue. I improvised some latches and locks to make it look secure.

For charging purposes (using a real charger), I put posts on the outside.

Box-Golf Cart 2-6V End to End ~ All Battery Sales and Service

[lswartz]

That looks perfect. The web site only gives outside dimensions so it looks like a tight fit. Did you bolt it to angle iron? I was thinking about bolting it & then when traveling adding a couple of straps that can be ratcheted (removed when stored).

Thanks much.

[Borwick]

Originally Posted by lswartz

That looks perfect. The web site only gives outside dimensions so it looks like a tight fit. Did you bolt it to angle iron? I was thinking about bolting it & then when traveling adding a couple of straps that can be ratcheted (removed when stored).

Thanks much.

The mounting rails (plastic coated angle brackets) were already there for dual Group 24 battery boxes. Basically, the same width. Just used 4 self-taping bolts to secure box to rails.

The batteries fit snug, but I have a strap around each one so I can pull each out.

They can fit a T-105 to T-145. I have a pair of T-125's as a happy medium.