Charge initiation point when left plugged in

[leonar40]

I am curious at what point below the targeted SOC the Tesla software initiates a top-off charge when you leave the car plugged in for a prolonged period (several days or more).

During my last charging session I set the charge point to 80%, the car charged to 81% and completed charge normally. Over the next several days the SOC slowly dropped as expected due to background load. It's now sitting at 77%. I'm a little surprised that the car hasn't initiated a charge to keep it right at 80%. Seems like it would want to keep the car within +/- 2% of the target SOC, but just curious if anyone knows what the threshold actually is.

 

[Rocky_H]

For many years, when it was just the S and X, before the 3 came along, that was a 3% drop that it did before running a refill charging cycle. The 3 has had a lot of weird issues with constant recharge kicking on and off a lot, so I'm not sure if they have tweaked that value in the 3 and Y for some reason, of if that was just some strange software bugginess. 3 and Y owners might have more detail of what that is now.

 

[lUtriaNt]

as a data point, sometimes im home for 7-10 days straight and my car will sit plugged in and not move for those days. i always charge to 95%. i have level1 (16A) charging.

lowest ive ever seen it go is 94%. ill see this from time to time and its normal.

i keep sentry on 24/7.

 

[leonar40]

As an interesting data point, I was sitting at 77% and wanted to top off charge to 80%, but there is no "start charge" button, as the screen and the app were still reporting "charge complete" from the last charge cycle. I even unplugged and re-plugged in the charger, but it did not start. Perhaps if I would have actually started the car it would have.

I did find a way to start charging though. I enabled conditioning from the app, and after a few seconds the car started charging while it was conditioning. I then turned conditioning off and the car completed the charge to 81%. So that seems like a little trick to jump start top-off charging.

 

[elptxjc]

An easier way to initiate charging is to raise the charging limit, and when the battery starts charging, just move it back to where it was .

 

[UncertainTimes]

For the past few days when I get in the morning after a charge session 80% set limit, the car says 77%. Must be a calibration thing.