Im am again developing some new CAN Bus BMS Controller for our own products and have an Idea or a Request.
Is it possible to extend the Victron "CANBUS BMS Protocol" in Chapter 3 (Messages sent by the Inverter to the BMS"?
In some situations it would be nice to get the VE Bus DC Voltage, meassured from the MultiPlus ..
When there is an offgrid System in a not compleetly discharged state, with disconnected Contactors, and an active CAN Communication, it would be nice, to know on the BMS side, if there is a rising Voltage (due to the fact, that there is a MPPT connected, and the sun is rising...) ..
I implemented a "sleep State" for the Controller. The Venus is sitting on the disconnected DC Bus and will start, when an MPPT is delivering Power to the DC Bus ... (ok.. I had such a situation).. so I can wake up my controller every "x" hours (on daylight time) and look, if there is a Voltage on the "other side of the contactor", higher, than my Batteries...
so there could be a reason to close the contactor, and bring the system up again before it get's compleetely doomed. -- as mentioned above .. I had such a System sitting for two weeks in a deeply snowed area, with no access, but an working mppt, that was not able to bring the battery up, because of a "saftey" disconnected Contactor...