These 12v batteries came with the trailer. Theyre mismatched and you can see the 2nd battery has more corrosion. Is that due to where the solar and ground wires are attached to the pair? The batteries only lasted 1.5 years and spent most of their life in storage with solar charging them everyday. They trigger low voltage alarm just turning on the faucet. The solar pos and neg were attached to the second battery.(top in picture)Is this an unbalanced way to wire two 12v in parallel? Or does it not matter which battery gets grounded to the frame?

Thats correct. + to + and - to - . I would have both grounded to the frame

they appear to be wired correctly, but I don't know what all those wires are for. How much solar are we talking about?

For proper balancing, any charging source or loads should connect to the + on one battery and the - on the other. If there is only one ground wire, put all of the positive wires on the other battery.There seems to be a bunch of positive wires already, making that difficult without a buss bar.If the heavy pair of wires on the lower battery are for the converter/frame ground and the heavy pair of wires on the upper battery are the solar charger, I'd switch either the ground or the power heavy wires. The smaller ones probably don't matter much.

wnjj wrote:For proper balancing, any charging source or loads should connect to the + on one battery and the - on the other. If there is only one ground wire, put all of the positive wires on the other battery.There seems to be a bunch of positive wires already, making that difficult without a buss bar.If the heavy pair of wires on the lower battery are for the converter/frame ground and the heavy pair of wires on the upper battery are the solar charger, I'd switch either the ground or the power heavy wires. The smaller ones probably don't matter much.Probably ideal, but when they're that close together, the concern about there being a drastic difference in voltage is unlikely.Are the batteries themselves dead? Is there water in them? I get the vibe that your solar isn't up to the task.

See para 3.7 herehttps://www.trojanbattery.com/pdf/TrojanBattery_UsersGuide.pdfAll loads and charging go to the same posts

Are these 12v parallel batteries wired incorrectly?

24 Replies

twodownzero
Explorer
May 15, 2019
wnjj wrote:
For proper balancing, any charging source or loads should connect to the + on one battery and the - on the other. If there is only one ground wire, put all of the positive wires on the other battery.

There seems to be a bunch of positive wires already, making that difficult without a buss bar.

If the heavy pair of wires on the lower battery are for the converter/frame ground and the heavy pair of wires on the upper battery are the solar charger, I'd switch either the ground or the power heavy wires. The smaller ones probably don't matter much.

Probably ideal, but when they're that close together, the concern about there being a drastic difference in voltage is unlikely.

Are the batteries themselves dead? Is there water in them? I get the vibe that your solar isn't up to the task.
wnjj
Explorer II
May 15, 2019
For proper balancing, any charging source or loads should connect to the + on one battery and the - on the other. If there is only one ground wire, put all of the positive wires on the other battery.

There seems to be a bunch of positive wires already, making that difficult without a buss bar.

If the heavy pair of wires on the lower battery are for the converter/frame ground and the heavy pair of wires on the upper battery are the solar charger, I'd switch either the ground or the power heavy wires. The smaller ones probably don't matter much.
2oldman
Explorer II
May 15, 2019
they appear to be wired correctly, but I don't know what all those wires are for. How much solar are we talking about?
Ranger_Smith
Explorer
May 15, 2019
Thats correct. + to + and - to - . I would have both grounded to the frame

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Are these 12v parallel batteries wired incorrectly?

24 Replies

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