question

nigelcharles avatar image

BMS preventing charging

I have operated a 12v 200A BMS will a pair of Victron 90Ahr batteries for 2 years now in a motorhome. It has suddenly stopped allowing charging from any of the three sources (alternator, EHU, solar). Power can be drawn from the batteries so there is no failure of the battery switch. With charging connected the voltage between the positive and either the chassis or load terminals of the BMS are at about 14.2v (as expected). The voltage between positive and the Li-Ion battery terminal is only 12.5v (battery voltage but not receiving charge). In case the remote switch had failed I tried shorting the terminals at the BMS to no avail. Connecting a temporary bypass lead from the load connection to the Li-Ion terminal allows the batteries to charge so I know that the problem is caused by the BMS. Is the BMS faulty or is there something else I can do?

BMS
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1 Answer
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

What temperature do the batteries have? The BMS stops charging at temperatures below 5°C.

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