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trulsla avatar image
trulsla asked

How can I set custom SOC in my Multiplus C 12/1600/70 without using VE config?

I have lithium batteries in my boat and do not want to charge them to more than 85% SOC normally except when I plan longer trips and want to top them off to 100%. Is it someway I can change that through either VRM or via Cerbo and Touch 50 without using VE Config? Would be a nice feature to have for managing lithium banks. Custom SOC and then shut off the charger when SOC is reached. Second feature would be to have the auxiliary charger on for maintaining current to the AGM starter battery bank.

MultiPlus Quattro Inverter Chargerbattery chargingLithium BatterySOC
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Alexandra avatar image
Alexandra answered ·

@TrulsLA

You can program over vrm however you still need ve config or Victron Connect. There is an option to set storage for lithium's so it sits a little lower in voltage but is refreshed every so often to keep the cells in balance (important if they are passively balanced)

Not sure why you cannot keep them at 100% as manufacturers never let the BMS charge the cells to 100% internally anyway. So the 100% they give you is not actually 100% of the cell capability. Case and point Winston cells are charged in batteries to 3.55v per cell but they can actually go up to 3.85 or 3.9vv per cell according to the datasheet. So unless you have a home made bank you have no worries keeping them at 100% for ages.

You could lower the charged voltages of the lithium that would be the only way really. Then you would have to reprogram to set them higher when in use.

The aux battery will charge when the main bank charges think it follows the main banks stages of charge.

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trulsla avatar image trulsla commented ·

Thank you. I have a Ritar Lithium 12V 300Ah battery. Any idea if on the BMS setup of Ritar? Could not find anything in the documentation.

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Alexandra avatar image Alexandra ♦ trulsla commented ·

No idea on the ritar. I have seen them but never opened one. If it looks like the lead acid drop in replacement then it is most likey passive balancing.

The random picture of the bms if it is to be believed that it is from the 12v batteries then it does look like passive balancing

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