After much time spent testing this, I have found a limitation around scheduled/solar charging and all current BYD EV models. Full explanations and a workaround follow, but these needs to be addressed both at the BYD software level + charger level (as per the option provided for Evnex chargers).
I have a BYD Dolphin, a Teltonika smart charger and ChargeHQ app (via OCPP). I have been trouble shooting this problem as it seems to apply to all BYD models, even after the latest OTA software update (1.3 in my case). Typically the car goes into deep sleep after about 15 minutes and won’t respond (consistently) to a charge schedule set up in Charge HQ, or the Teltonika app.
Manually waking up the car before the scheduled charge time does work and I tested this by starting the car a/c from the BYD app just before the 1am scheduled session (for 10 minutes). While this can be scheduled in advance, it has to be set up every time so is not a great option.
Appparently the car does pay attention to the BYD app, just not to the P2 state signal from the charger when it is plugged in and wants to offer scheduled power (it does recognise the PWM (Pulse Width Modulation) P1 state value on the Control Pilot pin of the Type 2 charging connector indicating that the plug is attached). So the car & charger stay in B status indefinately (A = unplugged, B = ready to charge, C = charging).
Useful links are BYD Atto 3 - not compatible and How do you smart charge a BYD Atto 3?. Evnex is probably the only charger that has addressed this, but hopefully BYD and/or Teltonika will also fix their software one of these days.
I have found a way around problems scheduling charging for my car, as follows:
- Schedule the charging from withinthe car e.g. daily from 1am to 6am if that is your cheapest electricity. You can then turn off the car, and before doing so, you will be asked whether you want to use the schedule or charge now. Select delayed charging.
- Plug the charger cable into the car, with this putting the car into a ready to charge state B (P1 - ready to charge).
- On your charger app, select to ‘charge now’ (or equivalent). The charger will attempt to start charging, but can’t, as the car has its schedule set.
- YMMV, but on my Teltonika charger, it will then move to a charging status (P2 - charging), showing 0.2Kw (1 amp) charge current being delivered to the car. This is enough to keep the BYD car awake until it starts charging at the full rate at the scheduled time of 1am.
- After charging at the full scheduled rate/time is completed, the charger reverts back to a 0.2kw charging rate and still shows a charging status. One issue is that this still locks the plug (unless the car is fully charged). To release this, I needed to manually stop the charger in the morning. I could only do this via the Charge HQ app (which manages the charger via OCPP). I guess rebooting or resetting the charger would also work.
The above would not help with scheduling solar charging controlled by the charger but does help if you have a fixed schedule.
