question

oldwave avatar image
oldwave asked

Mixing batteries

I have an install with two SOK batteries, but would like to add an external bms. Victron battery to power the multi plus inverter given it superior constant output. However I’m not sure how I would isolate the two battery banks given the difference in charge profiles. Anybody have any ideas for this? I’d use the sok’s for 12 volt loads and the victron for inverter loads . Thanks for any ideas. I’d rather not abandon the 400 amp hours I already have.

leisure batteries
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3 Answers
Peter Buijs - NL avatar image
Peter Buijs - NL answered ·

https://community.victronenergy.com/questions/143555/multiplus-123000120-and-sok-206ah-batteries-in-par.html Apparently you are not the only one...

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Alexandra avatar image
Alexandra answered ·

@Oldwave

With 12V batteries with different profiles, you would have to have separate chargers.

By different charge profiles, do you mean different chemistry, different capacity or different target voltages?

If you individually bus bar them and have a longer absorption time (same target voltages). The larger will charge up and balance.

The other options is to individually bus bar them and have ip65 or other 12 charger on the separate banks to take care of their needs. (I would get at least one anyway for bank maintenance)

I have not used SOK specifically. But have mixed a bank before like this. How the system behaves depends on how different the target voltages are.

Possibly share some more information on each of the batteries you are thinking of combining?

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oldwave avatar image
oldwave answered ·

Sure thanks for the reply. I have two 206 amp hour 12 volt litium batteries in parallel at the moment. I would want to add a Victron smart battery 200 amp hour. The charging profiles are slightly different given the internal bms of the SOK’s.

Charge Current (Per battery): 40a Preferred (50a Maximum)
Absorption Voltage: 14.6v preferred (14.4 Minimum)
Float Voltage: 13.8v preferred (13.6 Minimum)


I m not sure about the Smart batteries

Right now I have a 120 volt multiplus 2000 va

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