I have been trying to find a straight forward way to maintain an 80% SOC for my camper lithium batteries when it’s parked on the drive and not in use.
I tend to leave the van connected to ‘shore’ power over winter for a small heater and dehumidifier, in the summer I dont really need the heater just the dehumidifier.
The issue is when hooke up to shore the inverter will keep the batteries at 100% unless you use a Virtual Switch configuration in the VE Configure app, and if the solar is connected there is no easy way to configure that to not charge to 100%.
What I am looking for, perhaps a feature request, would be an option on the Cerbo to have an 80% SOC setting or another easier way to have a systemwide setting to stop the batteries being held at 100% ?
Depends a bit on which BMS you are using.
However, the easiest way to set an approximate 80% limit, is to use the Cerbo to limit the maximum charged voltage using the DVCC menu:-
here, you can set a value that corresponds to ~3.4V per cell (for LiFePO4). this will keep the cells near full charge but at less than the peak internal corrosion area.
Hi Mike thanks for the this.
I am not using any particular BMS other than what is built in to the battery.
I’ve not used the DVCC settings before - if I make changes here will that overide the current settings in the Multiplus and the MPPT ? Ie are the DVCC setting system wide?
setting the “limit charge Voltage” should work regardless of any CAN BMS connection or not. Except without the BMS connection, you would have to enable DVCC manually, and the charge current / voltage will not be controlled by the BMS.
I have confirmed it does not or at least that’s what engineers have confirmed. It is a CVL override, without a managed battery there is no CVL, hence why it refers to “managed battery”.
Without ESS there is no easy ways to do this that I’m aware of. I used to ‘fudge’ it with my van by using the “prioritize other energy sources” option and set my sustain voltage to an approximation of the percentage I wanted to hold at (for me I used 13.4v) and additionally I turned off my solar mppt charger to prevent that charging to 100% - not ideal but it did work.
When I wanted to fully charge before heading out I’d turn the solar back on and select the charge to 100% option.
