Charging lifepo batteries

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kanga1 asked May 14, '22

Charging lifepo batteries

Hi, we have 2x200amp hour Voltax LiFePo batteries wired in parallel for 12 volts to power our 4wd Canter camper truck habitat. We have an Enerdrive DC2DC e Power multi stage, multi source with MPPT charger, and a Victron BMV 712 Smart battery monitor.

The power sources are, the truck 24 volt alternator and 2 x 200 watt roof mounted solar panels.

Most mornings the Victron BMV app will tell me that the SOC is 88-92% I can check it again 10 minutes later and it will be showing 100% charged which i don't believe is possible. Can anyone help solving this issue?

BMV Battery Monitor SOC

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Answer 1 · 2022-05-14T04:12:16Z

Nev answered · May 14, 2022 at 04:12 AM

You may have the 100% SOC synchronisation point triggering too early by having the "Charged voltage" set a little low?

If so you could experiment a little upwards.

Our 4 cell 300Ah LiFePO4 battery is set at 14.0V. It is always full at 14.1V.

I suspect the settings on your BMV 712 are very similar to our Victron SmartShunt.

screenshot-20220514-155635.jpg (47.0 KiB)

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kanga1 commented · May 14, 2022 at 09:42 PM

Thanks for you for your reply. The volts readout on the actual batteries seems to max out at 13.4 when showing 100% but is often around 13.31V. I have set the charged volt value at 13.3, can't do 14 like you. The tail current was 4% but I have changed this to .5%, I'll have to read up on my charger.

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Nev kanga1 commented · May 15, 2022 at 05:22 AM

Are you using the VictronConnect app to adjust your BMV 712 settings?

If so you must be able to tweak the "Charged voltage" setting.

13.xV is far to low.

I just checked your BMV in VictronConnect using simulation mode.

Cog at top right > Battery > Charged voltage >

I would try 14.1V.

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Answer 2 · 2022-05-15T07:34:29Z

Paul B answered · May 15, 2022 at 07:34 AM

Have a look at these as they may help you understand the settings better

https://www.victronenergy.com/media/pg/SmartShunt/en/all-features-and-settings.html#UUID-37b15df6-8521-aa94-3dfd-7f1d92e7f6f4

https://www.youtube.com/watch?v=mEN15Z_S4kE

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