Overnight drain with solar tracking

I wonder if anyone has seen the same behaviour as I have, that my Tesla battery drops by a few % overnight when using Charge HQ.

Tesla Model S 2018, Tesla mobile connector (10A), Solis inverter

I’ve set Charge HQ to only charge when there’s solar, so on a good day adds 12 kWh between 10am-5pm. The last couple of days there’s been patchy sun, so only 8 and 6 kWh. However I checked the state of charge last night, and it was 70%. This morning it was 66%, and then dropped to 65% shortly after it started charging. I was checking because I think there was similar behaviour the day before, and Charge HQ doesn’t log the state of charge on the historical stats.

There are a few possibilities I can think of:

  • this is regular Tesla phantom drain (I don’t use sentry mode)
  • the regular polling by Charge HQ is waking the car and draining the battery
  • the % state of charge is inaccurately reported by the car
  • the regular on/off charging is making the car work by heating/cooling the battery
  • there was a software update this week and the wifi is patchy to the car, so it spent a long time trying to connect

I’ve put in a blackout period between 5pm and 9am because I don’t want it to try to charge then. Any other ideas or people with the same problem, I’d be keen to hear!

@kylish our logs show that your vehicle is failing to fall asleep.

Modern Tesla vehicles should fall asleep even if they are being polled by an app such as Charge HQ, however the older Model S/X may stay awake when being polled. For this reason, Charge HQ stops polling for 15 minutes every 45 minutes to allow the vehicle to sleep, see this page for details.

In your case, the vehicle is not falling asleep during these 15 minute windows.

Do you have any other third-party apps connected to your vehicle? That might explain it.

Hi @jay thanks for checking this out!

I’ve removed ev.energy’s access to the car, so only Charge HQ has the 3rd party connection now. Let’s see if that improves things. I installed their app to do the same as yours but it didn’t have the same level of integration with my inverter. My vehicle seems to be on the cusp of modern/not modern - it doesn’t have the ‘energy saving’ setting that the older vehicles do, but was definitely built around the time of the transition.

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To close this out, disconnecting ev.energy has solved the problem. My car is retaining its charge significantly better.

Thanks for this great app!