I've successfully installed this inverter/charger to my diy campervan and recently configured it for heating hot water tank when battery charge is higher, i.e. use spare solar energy.
There is two assistants installed:
- Two-signal BMS support - input to enable/disable both charger and inverter by ElectroDacus SBMS0 monitoring eight 280Ah Chinese LFP cells
- Generator start and stop - controlling ACOut2 relay wired to 1000W/230VAC hot water tank heater.
Latter assistant has following configuration:
- Use ACOut2 relay to start generator
- Open relay to start generator.
- Start generator when load higher than 2000 Watt for 10 seconds
and stop generator when load lower than 1000 Watt for 30 seconds. - Start generator when battery voltage is lower than 26.50V for 10 seconds.
- Stop generator when battery voltage is higher than 26.56V for 10 seconds.
- The generator is not stopped by AC input.
This works when battery has very high SOC, those voltage values were observed from Multi when BMS was calculating 80% SOC.
The problem is that when 1000W load is connected, battery voltage drops, and that causes oscillation where load is powered 10s, then off until battery voltage rises back to the threshold level and repeated.
My campervan has Orion Tr-Smart DC-DC charger, MPPT and Multi to charge battery, latter is used very rarely.
I'm yet to discover good description about how "Enable battery monitor" and related settings actually work in Multi. I've tried it some time ago but turned it off because of odd behaviour. If this internal battery monitoring works properly, it enables use of SOC parameters in generator assistant control which I believe is less oscillating.
Any hints or pointers to get this working better?
