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Big Difference in SOC of the Chassis Batteries
Replaced all four chassis batteries with new Interstate group 31, in Dec. ’21.
I topped off the batteries before the install. I take the bus out for an hour ride once a month. Today I hooked up my two 12 volt chargers, one to the top right battery, and one to the bottom right battery. The State of Charge on the top right battery was 78%. But only 6% on the bottom right battery. Why would there be such a huge difference?
Maybe a problem in the battery connection wiring that one set is draining so much more?
I then tried hooking up to the Vanner with one 12 volt charger, red to 24 volt, black to 12 volt, and the charger read 92% charged.
I’m wondering if the second bank of chassis batteries is somehow connected to the house batteries, (which I know are shot) and thereby giving the super low charged percentage.
Thoughts?
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11 Replies
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Converter, chassis type, and year.
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Also maybe pictures that show your batteries, cables and how they route to your Vanner.
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Based solely on the number of phone calls I have received and posts I have read over the years my guess is the batteries are not cabled correctly. If they are however y second guess is a faulty equalizer.
Read the electrical section in the Prevostcar owner’s manual.
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Another guess would be a bad/defective battery. I’ll give you 4 guesses which one it is 🙂
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’96 XL
Here are some photos. Also, I tried hooking the single 12 volt charger directly to the Vanner. Red to 24volt, Black to 12 volt. 3 hours later the SOC had not changed. I’m wondering why not hook the Red lead to the 12volt connection and the Black lead to the common ground, as that would seem a complete circuit.
The batteries do charge when I use the two 12 volt chargers method.
According to the diagram, the batteries look like they are hooked up correctly. There are a couple extra leads.
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As details emerge, and more information is provided, to me this is not a forum question or discussion.
Given the information provided and the photos showing wiring not typical of what is usually found on a conversion at the equalizer and no clue if the wiring or battery cables are even correct this is a problem best solved by someone at the coach with a tester and access to a whole lot more information.
I hate seeing what might be owner made changes because of lack of documentation, skill levels, and reasons for the modifications.
Chassis batteries should be able to sit for months and months without a charge and still retain the ability to spin and start the engine.
2000 Featherlite H3-45
2024 Jeep Grand Cherokee
Leesburg, FL -
Don-
All 4 batteries were replaced at the same time Date Coded 12/21
And they were load tested at Napa to make sure they were all good.
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Luc, that was then, this is now.
It’s not unusual for a battery to fail shortly after purchase.
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Luc, maybe it’s your equalizer? Follow the test instructions on p.12 of this pdf: https://vanner.com/manuals/EQUALIZER-60-SERIES.pdf
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Don-
I think you may be on the right track here. That there is such a difference in the SOC, seems to point to lack of battery equalization. And after I hooked up the single 12 volt charger to the Vanner, even after 3 hours, it didn’t change the SOC. I will check out the link.
Thank you!
BTW What battery load tester do you use?
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