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Teamfoxy · 03-07-2019, 06:25 PM

My understanding of wiring two 6 volt batteries in series is that the negative terminal of one battery is wired to the positive terminal of the other. The positive wire from the coach goes to the positive terminal of one battery and the ground wire goes to the negative of the other. Thats what every diagram that I have found shows.

My new (to me) coach has two 6 volt batteries wired as follows: The positive terminals of each battery are conected together. The positive coach wire goes to the negative terminal of one battery and the ground wire goes to the negative terminal of the other battery. If I put a volt meter to the terminal to which the positive wire is attached, and the terminal to which the ground is attached, the reading is 12.6 volts. Reverse the leads and it is -12.6 volts. So obviously the system is working correctly even though the wiring seems weird.

Everything that operates on 12V is functioning normally. The isolator is charging the batteries correctly because there is an increase in voltage at the battery. The converter is charging the batteries correctly. So my inclination is to just leave things the way they are. Is there something that I am missing here?

powercat_ras · 03-07-2019, 06:30 PM

You must be mis-identifying positive and negative on one of the batteries. If it was really positive to positive nothing would be functional. If you still have lighting, fans, etc. when disconnected from shore power and generator off then its positive to negative. If nothing then it might really be wrong and a protective fuse in the positive coach battery lead has blown. Good luck.

cavie · 03-07-2019, 06:33 PM

Quote:

Originally Posted by Teamfoxy

My understanding of wiring two 6 volt batteries in series is that the negative terminal of one battery is wired to the positive terminal of the other. The positive wire from the coach goes to the positive terminal of one battery and the ground wire goes to the negative of the other. Thats what every diagram that I have found shows.

My new (to me) coach has two 6 volt batteries wired as follows: The positive terminals of each battery are conected together. The positive coach wire goes to the negative terminal of one battery and the ground wire goes to the negative terminal of the other battery. If I put a volt meter to the terminal to which the positive wire is attached, and the terminal to which the ground is attached, the reading is 12.6 volts. Reverse the leads and it is -12.6 volts. So obviously the system is working correctly even though the wiring seems weird.

Everything that operates on 12V is functioning normally. The isolator is charging the batteries correctly because there is an increase in voltage at the battery. The converter is charging the batteries correctly. So my inclination is to just leave things the way they are. Is there something that I am missing here?

Your gonna have to provide a picture because per your description his cannot work.

Bob_C · 03-07-2019, 06:34 PM

Your top paragraph is the correct way.....that equalizes the batteries...

HaRVey 74.5 · 03-07-2019, 06:34 PM

Since it's working correctly, my guess is either you misread the markings on the batteries or were judging by battery cable colors, which might have been installed abnormally (i.e. they used red for negative and black for positive)

twinboat · 03-07-2019, 07:29 PM

If the batteries were run down, completely dead, and hooked up that way, one would charge up backwards.

If its actually wired up the way you discribe, It will work, but not well.

Best bet is to replace them both soon.

Check each battery with your meter, + & - , and send some pictures to prove your situation if true.

vsheetz · 03-07-2019, 07:34 PM

Post some pictures.

Ray,IN · 03-07-2019, 08:16 PM

If you only have 2 6V batteries, and wire them to make a 12V system, they will be wired like this:

ANY different wiring is wrong.
Now if you have 4 or more 6V batteries in a bank, they must be wired as you see in The 12V side of Life

Dutch Master · 03-07-2019, 08:21 PM

Hello TeamFoxy,
First, you are correct about wiring 2 six volt batteries in SERIES. However, from your description your current configuration of the batteries are wirred in PARALLEL. Since you measured the voltage using the positive and negative battery terminals, resulting in a 12 volt reading, your batteries are 12 volt type and not 6 volt. Series configuration results in increased voltage. Parallel results in increasing current. This is why your 12 volt system is working correctly.
Best Regards
Dutch Master

Teamfoxy · 03-08-2019, 05:15 AM

Those of you who said that I mis-identiried the terminals are correct. But in the attached picture, I think you can see why. The previous owner placed both of the protective red caps on the side nearest to the front of the compartment and has a black protective cap on the terminal where the red taped wire attaches. The plus on the left battery is visible, but the red wire covers the negative marking.
BTW, the cells all test good with the hydrometer and they seem to hold a charge just fine.

cavie · 03-08-2019, 05:46 AM

Quote:

Originally Posted by Teamfoxy

Those of you who said that I mis-identiried the terminals are correct. But in the attached picture, I think you can see why. The previous owner placed both of the protective red caps on the side nearest to the front of the compartment and has a black protective cap on the terminal where the red taped wire attaches. The plus on the left battery is visible, but the red wire covers the negative marking.
BTW, the cells all test good with the hydrometer and they seem to hold a charge just fine.

The other confusing part of the equation is the batteries orientation to each other. One is 180 degrees from the other. Most people would lay them side by side facing the same direction.

ScoobyDoo · 03-08-2019, 07:32 AM

Quote:

Originally Posted by cavie

The other confusing part of the equation is the batteries orientation to each other. One is 180 degrees from the other. Most people would lay them side by side facing the same direction.

I would think it better to have the batteries setting so the cables that go outside the box are near the direction the need to go. And the cable that connects the batteries together is out where it is easy to get to. If cables need to be disconnected, take the link off first, and then no chance of burns while unhooking the others.