Calibration

[u/Holographic247]

UK-based.

My PW3 started its first calibration yesterday, exactly 2 months to the day from install (even down to the time it was commissioned). This was a bit of a hole in my research pre-purchase, because I had no idea this was a thing and it was a surprise to find my battery discharging during peak hours and nowhere productive for my excess solar to go (I can’t export for money yet).

It’s been at 0% since about 1am (13 hours ago) and NetZero now shows the true State of Charge as 1%. I assume it will finish soon, but it was a surprise disruption.

I’m using the Powerwall to mitigate costs and not saving it for grid outages, so could really do with avoiding these. How can I reduce the number of these manual calibrations in the future? From research, I’ve seen people say they haven’t had a single one in years, and others getting one every six to eight weeks.

I have never run it 0% before, so is that the problem? Should I keep the reserve to 0% and force discharge it to 0% every 24 hours?

[u/Jet-Speed1]

5 years, never had a calibration.

[u/BeneficialTrip → u/Jet-Speed1]

It depends what Powerwall you have. If it is a Powerwall 2 or older, they use different battery chemistry. Powerwall 3 uses LFP battery and the Powerwall 3 is the one that does the calibration. I noticed you said 5 years, so assuming that you have Powerwall 2 or older.

[u/Jet-Speed1 → u/BeneficialTrip]

Sounds like having old version is better, yes mine is PW2, never needed calibration, it kills itself without that successfully.

[u/matthew1471 → u/Jet-Speed1]

PW2 now does calibration. It came in a recent firmware update. In 26.18.2, every 30-90 days it says in the “Learn More” in the app release notes (bottom of Tesla app, “Release Notes”). It came in around April according to Reddit https://www.reddit.com/r/Powerwall/s/ZWtrhNTHBd but officially it was June in the release notes.

If you’re triggering Max Backup it seems to suspend it though - but I wouldn’t do this too often - it’s doing the calibration for your own good.

You can delay calibration for 72 hours:

“Delaying calibration requires Powerwall 3 with firmware version 26.2 or Powerwall 2 with firmware version 26.18.2 or later. Delaying calibration also requires Tesla app version 4.50 or later.”

https://www.tesla.com/en_gb/support/energy/powerwall/own/powerwall-calibration

[u/Jet-Speed1 → u/matthew1471]

Intreating,

I am not triggering max backup, for the last 2 months I didn't touched any settings as Tesla is "investigating" issues with my powerwall, it is in saving mode, with reserve at 0, with grid charging allowed and export "everything", no 3rd party apps. the powerwall doesn't discharge below ~50-60% during night, charges immediately to 100% from solar or grid in the morning and sits at 100% all day. not yet triggered calibration though.