Charging Lifepo4 house and AGM Starter Batteries

Q&A and troubleshooting
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1

I just swapped my AGM house battery bank to a 12V 628hA LifePo4 battery bank. The LiFePo’s cells (4 x EVE MB56) are controlled by a JK-B2A8S30P (not inverter) BMS. The BMS communicates via BMS-CAN with a Victron Cerbo. I have turned on DVCC and let the BMS controll the Multiplus 12/3000/120 and my MPPT 150/85. I am still testing, but so far I did not identify any issues.

I am now wondering how to (re-) integrate the AGM starter battery.

Do I have to decouple the AGM’s somehow?
How can I charge the AGM’s with the correct charging profile, do I need supplemental hardware?
I have read somewhere I can use a “trickle charge” output from the Multiplus.

Thank you very much for your opinion. I am also happy to share my expierence with this setup.

2

See here for details of the Multiplus trickle charger, it is not really a proper charger. With your install the BMS isolates all loads so no worries in that regard.

The usual option is to install a DC to DC charger, a small one from the Victron Orion range would be suitable. The isolated 12/12-18 (12V to 12V max 18A) is the smallest.

3

You definitely read it somewhere.

It isn’t a proper charger as mentioned. It will stop it going flat.

Other option is just a 230v 12v charger to run off the ac output of the inverter. Also is the best way to ‘recover’ if you have parked too long.