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tiagojones avatar image
tiagojones asked

Trouble Charging Battery Bank

Hello as the title states I am having trouble getting my batteries to charge. I am using two 200W solar panels (wired in series) that connect to a Victron 100/50 charge controller via 10AWG wire. My battery bank is two 12V, LiFePO4, 100Ah batteries wired in parallel. My charge controller is receiving around 40V from the panels.


In absorption mode, it will only supply around 1 Amp to the battery bank so my batteries are slowly being used up even with the only thing drawing power being my 12V fridge. I've checked my wire connections and everything looks right. After a few hours of troubleshooting I've come up empty handed. Does anyone have any ideas on how to get my batteries to actually charge?



screenshot-20230604-142715.png

battery charging
screenshot-20230604-142715.png (136.6 KiB)
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2 Answers
ingo21 avatar image
ingo21 answered ·

Does anyone have any ideas on how to get my batteries to actually charge?

your battery is charged at 14.36V and the charger goes in absorption mode , which looks right to me...i would not charge my lifepo4 battery higher than 3.6V per cell , this is what you got at 14.36.

the fact you discharge more in absorption mode than you charge is another thing.

do you have the settings for the Victron 100/50 and more important do the battery(ies) have a BMS , if so what are the settings of the BMS?


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kevgermany avatar image
kevgermany answered ·

You're misreading the display. The MPPT is charging at nearly 4A according to the battery lines.

If there are other loads at the same time, the batteries may not get all of the MPPT output.

Check wiring, fuses, switches for resistance/loose connections. Might be only one panel working due to broken cable.

But may be due to poor illumination, dirty panels, BMS limiting charge.


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