Hi Victron,
I hope this hasn't already been addressed in a previous question - I did do a search and couldn't find the information I was looking for.
I have a 10kW (peak) off-grid solar system with 30kWh of batteries and have recently installed an EVCS NS because I have purchased an EV.
I have noticed 2 things when charging:
- When charging the car (when there is sufficient sun available) the car power is usually increased to the point where there is only about 2-300W going into my house batteries. This is the case until there is so much power available that my car is at the maximum, and then the house batteries starts to increase.
The way I was expecting the system to work is that it would only use power for the car when the house batteries are in the constant voltage phase, and that the system would adjust the car power to try to keep the house batteries as close as possible to the constant voltage phase (thus only using surplus power for the car). - There is an issue when the sunlight starts to diminish to the point where there is insufficient surplus power available to charge the car at minimum (6A) charge current. So I have "Allow battery/grid power for auto mode" enabled and set to 5 minutes. When charge starts to be taken from my house battery in order to charge the car at minimum current, this timer kicks in and after 5 minutes the car stops charging. The problem is that when the car stops charging, there is still enough sunlight available to charge the house battery and so the system probes again and the 5 minute timer starts over again. This leads to quite a bit of my house battery being drained into the car at the end of each day before it gets quite dark.
The better way to handle this, I think, would be to start a timer after stopping the car charging so that the system doesn't probe again for some time. Oh and by the way, why can the "Allow battery/grid power for auto mode" timer not be set to less than 5 minutes? I think 1 minute would be very good for that time, and perhaps 10 minutes for the "Delay to probing" timer that I mentioned. That way the system would drain very little power from my house battery during this dimming period.
I'll be very interested in your responses. Thanks in advance!
-Helmut
