question

ddutton avatar image
ddutton asked

Batteries disconnect Inverter when full

Victron Multiplus II 24/3000/120. Overkill BMS

When my batteries are full, LiIPO4, the inverter kicks off. The BMS is kicking out due to over cell protection, I have one cell that I can't get balanced. I'm pretty sure the inverter is kicking off due to the BMS. Any suggestions for discharging a single cell, I tried searching for 3 volt light bulbs. I'm also stuck on firmware version 492, inverter kicks off when trying to update to version 506 by MK3 connected to computer.

Multiplus-IIbattery chargingLithium Battery
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3 Answers
seb71 avatar image
seb71 answered ·

What is the Absorption voltage?

You can use a resistor to discharge a cell.

What is the cell capacity (Ah)?

When the battery is full, what are the cell voltages?

To give the BMS more time to equalize the cell charges, reduce the Absorption voltage and also maybe reduce the charging current.

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ddutton avatar image
ddutton answered ·

I have a 30 ohm resistor I use to connect the inverter to pre-charge, would that work? 280 Ah battery.

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seb71 avatar image
seb71 answered ·
Is that a power resistor?


30ohm will give you a discharging current of 3.6V/30ohm = 0.12A.


Depending on how much you need to discharge the cell, it will take a while for such a large cell.


Monitor the cell voltage as you discharge it.


You did not answer the question about Absorption voltage. It might be too high, causing this issue.


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