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Tim Mead avatar image
Tim Mead asked

BMV-712 State of Charge Returning to 100%

I have a BMV-712 that is used to monitor the state of charge of a 100Ah LiFePO4 battery. I can see it measuring the load (e.g. I have a fridge pulling 65W) and the SoC begins to drop from 100%. However, when the load switches off (e.g. the fridge reaching temperature), the BMV-712 returns to 100% - it does not retain the prior value (i.e. 97%). That is, it is not accumulating at all. There is no active charging of the battery at this time.


Has anyone experienced this? Is there a way to fix it? Without this the product is useless.

BMV Battery Monitor
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3 Answers
Gregory Cavanagh avatar image
Gregory Cavanagh answered ·

What do the settings look like on the settings page?

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Tim Mead avatar image
Tim Mead answered ·

Battery capacity: 100Ah

Charged voltage: 13.2V

Tail current: 4.00%

Charged detection time: 3m

Peukert exponent: 1.25

Charge efficiency factor: 95%

Current threshold: 0.10A

Time-to-go averaging period: 3m

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Gregory Cavanagh avatar image Gregory Cavanagh commented ·

Change the charged voltage to something like 14.0 - 14.2 and see if it starts working

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nigelfxs avatar image
nigelfxs answered ·

Hi Tim, it looks like you have setup the BMV-712 with Lead-Acid battery parameters. A LiFePO4 battery typically requires a Peukert exponent of 1.05, charge efficiency factor 98% (or 99%) etc.

You will find that the BMV will work really well once it is properly configured to your battery.

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