This bug had been previously squashed, but it appears to have come back to life. Off grid home, and if the house battery is full and the PV arrays are throttled down (both DC and AC coupled) when I plug the car in, the EVCS remains in “Waiting for Sun” state indefinitely, despite plenty of array potential available. See screenshots.
If I switch the EVCS to manual mode the system wakes up and tracks the array appropriately, and once I discharge the batteries ~30 minutes or so I can switch back to Auto, but that’s not the way this is supposed to work.
Folks, this shouldn’t be that hard. If the inverters are operating offgrid and output frequency is above nominal and/or PV input voltage is intentionally off MPPT, then there’s by definition excess PV power available that is being curtailed. If either condition exists, the system should not sit “waiting for sun” - it should send power to the car so the battery condition stops being idle and the controllers stop regulating and allow the array to contribute to their fullest extent.
Yes, EVCS should wake up MPPTs. The fix was added a time ago.
The exact problem in this case is that the backup battery stops charging at 90%. However, EVCS expects it to be up to 99%. From the EVCS side, battery idle state detection will be improved in the upcoming version, and it will fix such situations. For now, the only way is to allow backup battery charging to 99%.
Or join to beta-testing of these improvements?
The challenge is I don’t control where the battery stops charging - that’s managed by the BMS, and is driven by temperature and other factors somewhat out of my control. But I will say that with any battery - especially lithium - once above 90% there’s typically surplus charge power available, few batteries are happy accepting full current all the way up to 99% SOC. Seems like a bad plan to wait all the way for 99% to trigger a diversion load, especially a diversion load that is variable and controllable.
I’m absolutely game for beta-testing, I’ve been participating in Cerbo and display betas for a while. Let me know how I can help!
Situation: Throttled down PV by DESS pricing (12 o’clock grid prices negative) from 4 kW to 1,5 kW to feed home loads.
Battery was charged to 99%
EVCS minimum setpoint for ESS Battery is 80%
EVCS minimum charge capacity set on 16A, maximum on 25A
“waiting for sun”
Then i changed EVCS to manual 25 A and it started charging the EV
