Does the Model S stay fully charged when plugged in?

[dannycamps]

Greetings,

I have a question. The other day for kicks and giggles, I turned on Sentry mode full-time in my Model S. Previously I would enable it only when parking in sketchy areas but wanted to see what (if anything) it would pick up in my driveway.

So I got home at the end of the day, plugged in my Model S to my 240v EVSE and went in the house. A few hours later, I got a notice (normal) that the car completed charging at 301 miles.

The following morning when I went out to my car, the range was down to 285. Now I know that Sentry mode is a bear on the range because the car doesn't sleep but I assumed that because it was plugged in, the car would just keep itself charged up as needed. This does not appear to be the case and behaves differently from my previous EV (Chevy Volt).

My question is - if the car is plugged in and completes charging but then loses range due to a draw (battery conditioning, Sentry, etc...) will it restart charging on its own to bring the battery back up to the charge limit or does the cable need to be removed/re-inserted to restart charging? My experience is telling me it's the later but I wanted to confirm.

Thanks all,
DJ

 

[Bigriver]

There is a lower range it will get to before it charges back up to the limit you have set. It’s been awhile since I did this (charge and then have it plugged in until it lost below the set point) but I’m remember it was about 3% of the battery capacity. So it would get to 77% before charging back to 80%, for example.

 

[SilverGS]

@dannycamps . You don't have to unplug/plug it in to start charging back again. Just as @Bigriver mentioned, it gets down to a certain percentage before it will automatically start charging again.

I don't remember the specifics, but I had mine plugged in for 3 days and I didn't drive it. When I first plugged it in to charge, it charged to 90% as per my set limit and then it dropped on average about 15km per day for 3 days and then on the 3rd night, it started charging again.

 

[Rocky_H]

My question is - if the car is plugged in and completes charging but then loses range due to a draw (battery conditioning, Sentry, etc...) will it restart charging on its own to bring the battery back up to the charge limit or does the cable need to be removed/re-inserted to restart charging? My experience is telling me it's the later but I wanted to confirm.

There is kind of a two part answer to this depending on a setting.

There is a lower range it will get to before it charges back up to the limit you have set. It’s been awhile since I did this (charge and then have it plugged in until it lost below the set point) but I’m remember it was about 3% of the battery capacity. So it would get to 77% before charging back to 80%, for example.

It is this if you don't have scheduled charging enabled, so it will charge at any time. So it will do this thing where it lets it drift down by about 3% before doing another charge cycle to refill.

But if you do have a scheduled charge time enabled, it will wait for that next time to come up. So in the above case, it could keep going down from 77% to 76, 75, etc. if there are still several hours until the scheduled time. So instead of 3% down from your charge target, it might go down a bit further to 4 or 5% before it hits that recharging cycle.

 

[dannycamps]

Thanks all for the responses. Much appreciated.