question

woer123 avatar image
woer123 asked

Inaccuracies with BMV-712

I don't know what else to do with my BMV-712. Its about a year old. For about 8 months, it worked okay. There were issues with SOC resetting to 100% but that was fixed once I adjusted the parameters.

For the last 4 months, the unit just doesn't work. It always shows a positive amperage change even when the battery is in a discharge state. For example, I could have 1900W of energy being pulled from the battery and the unit shows a positive 200W of charge.

The shunt is wired as follows using a 4/0 cable:

chassis ground -> shunt -> negative of LiFePO4

I have calibrated the BMV 5 different times by removing the cables from the BMV and hitting the calibrate button.

when I do that, the BMV becomes accurate. I get the proper reading for discharge and charging. The problem is that after a few hours, the unit reverts back to always showing a charge even when there is a significant discharge. This happens every time; I calibrate, works for a few hours, goes back to being inaccurate.

Due to this problem, the unit is always showing me a 100% SOC since the battery is always miraculously charging.


Is this a dead unit or is there something else I can do to get this $200 unit to work

BMV Battery Monitor
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1 Answer
kevgermany avatar image
kevgermany answered ·

I think you should get it to the dealer for warranty service.

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