I would like to propose a change that would add the option to set the “sustain voltage” from within VenusOS, or even better, directly from VRM. By “sustain voltage” I mean the parameter that is configured during the setup of the ESS assistant installed via VEConfigure.
I have a fairly complex ESS setup which, unlike standard system configurations, includes a significant number of DC loads. This setup powers, among other things, the entire building’s lighting and the network equipment. The ESS operates correctly as long as there is sufficient energy available. The system discharges the battery down to the minimum SOC level, and then, as expected, switches to pass-through mode. However, the DC loads continue to draw power from the main battery. Once the SOC drops by 5% below the configured minimum threshold, the system automatically starts recharging the battery with the current I defined in VEConfigure.
This behavior repeats depending on the energy demand and the amount of DC power consumption — sometimes up to three times a day. Setting the “sustain voltage” to an appropriate level eliminates this problem, but as a result, it also prevents the battery from discharging below that voltage, even if a much lower minimum SOC value is configured in the ESS settings.