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Accidental charge to 100%?

Halcyon

Member
May 9, 2016
101
37
CT
Not sure if this has happened to anyone. My car has not been driven in a week and when I come back, it was charged to 100% and have no idea when this happened. I did not set it to this level on the app or the car, however the MCU needed a reboot. When the MCU crashes and is not rebooted, does the car automatically charge to 100% while plugged in?
 

RedMS

Member
Dec 5, 2017
355
373
USA
That is strange. Your battery is going to be fine. It’s not preferable to keep the battery full for extended period but I doubt this one time will have and effect
 

boaterva

Supporting Member
Apr 2, 2016
7,567
3,739
Northern Virginia, USA
I've had a couple of 'overcharges' but not to 100%. I've got it set to 80% and it's gone to 83 or a little higher several times. Once from a rogue firmware install and once when the servers were down. Can't figure why in either case. Now I reboot the MCU after all firmware installs, to be safe.

As was said, going to 100 once and not staying there for hours and days won't do any harm. If you make a habit of it (weeks and weeks), it's when it will hurt. You can drive it down to 90 or less to get back to where you want it to be, or just let the car's vampire drain eat it up (which may take sometime). May be better to run it down to 95 or 90 and then let vampire do the rest.

As for your question, there is no default setting, and something must have just said 'start charging'.
 

Halcyon

Member
May 9, 2016
101
37
CT
I've had a couple of 'overcharges' but not to 100%. I've got it set to 80% and it's gone to 83 or a little higher several times. Once from a rogue firmware install and once when the servers were down. Can't figure why in either case. Now I reboot the MCU after all firmware installs, to be safe.

As was said, going to 100 once and not staying there for hours and days won't do any harm. If you make a habit of it (weeks and weeks), it's when it will hurt. You can drive it down to 90 or less to get back to where you want it to be, or just let the car's vampire drain eat it up (which may take sometime). May be better to run it down to 95 or 90 and then let vampire do the rest.

As for your question, there is no default setting, and something must have just said 'start charging'.

Thanks - that's a good idea on resetting after firmware installs. The MCU crashes are annoying because it doesn't let me summon the car out of the garage. It could have been at 100% for a week or a day. I'm guessing somewhere in the middle.
 

boaterva

Supporting Member
Apr 2, 2016
7,567
3,739
Northern Virginia, USA
Thanks - that's a good idea on resetting after firmware installs. The MCU crashes are annoying because it doesn't let me summon the car out of the garage. It could have been at 100% for a week or a day. I'm guessing somewhere in the middle.
What firmware are you on and how old is the car? Crashes seem to be a 'feature' of the new MCU2, but hopefully newer firmware(s) are fixing that!
 

Halcyon

Member
May 9, 2016
101
37
CT
What firmware are you on and how old is the car? Crashes seem to be a 'feature' of the new MCU2, but hopefully newer firmware(s) are fixing that!
On MCU1 unfortunately. On 2018.18 and early 2017 build.

Curious how frequent crashing is for us MCU1 folks. Mine seems to do it every 2-3 months or so.
 

Jayrod

Member
May 6, 2018
198
95
FL
Not sure if this has happened to anyone. My car has not been driven in a week and when I come back, it was charged to 100% and have no idea when this happened. I did not set it to this level on the app or the car, however the MCU needed a reboot. When the MCU crashes and is not rebooted, does the car automatically charge to 100% while plugged in?

Over a long period of time it would have an effect but not 1 time.
 

MorrisonHiker

S 100D 2021.4.18.2
Mar 8, 2015
9,837
9,209
Colorado
Thanks - that's a good idea on resetting after firmware installs. The MCU crashes are annoying because it doesn't let me summon the car out of the garage. It could have been at 100% for a week or a day. I'm guessing somewhere in the middle.
Due to vampire drain, I would guess it was only at 100% for a few hours. Of course it could've charged to 100% a few days ago but then it would've drained down a few percentage points and then charged back up to 100% before you noticed it.
 

Halcyon

Member
May 9, 2016
101
37
CT
Due to vampire drain, I would guess it was only at 100% for a few hours. Of course it could've charged to 100% a few days ago but then it would've drained down a few percentage points and then charged back up to 100% before you noticed it.
It was plugged in the entire time unfortunately.
 

GOPJEW

Member
Jul 5, 2015
571
255
Potomac, MD
On MCU1 unfortunately. On 2018.18 and early 2017 build.

Curious how frequent crashing is for us MCU1 folks. Mine seems to do it every 2-3 months or so.
That's a lot of crashes...my S had it happen maybe once in 3 years.

My X with new MCU crashed once but it was a known issue that has been fixed with an update...supposedly....
 

Halcyon

Member
May 9, 2016
101
37
CT
That's a lot of crashes...my S had it happen maybe once in 3 years.

My X with new MCU crashed once but it was a known issue that has been fixed with an update...supposedly....
I have no idea what's normal. It's never crashed while I've been driving.
 

Freedom101

Member
Jul 8, 2017
199
179
Vancouver BC
I usually try to check in with the app every couple days when I'm away. Maybe for next time. I wouldn't worry about the battery it will be fine over such a relatively short period.
 

bob_p

Active Member
Apr 5, 2012
3,706
2,815
Tesla should modify the onboard software to only use the 100% charge level setting for a single charging session, and then automatically reset the charge level back to 90% after that.

When leaving for a road trip, I set the car to 100% one time to get max charge for the first leg of the trip - and forget to lower the level to 90%, so the first overnight charge was to 100%...
 

DCGOO

Active Member
Nov 24, 2015
1,579
916
Indianapolis, IN
Tesla should modify the onboard software to only use the 100% charge level setting for a single charging session, and then automatically reset the charge level back to 90% after that.

When leaving for a road trip, I set the car to 100% one time to get max charge for the first leg of the trip - and forget to lower the level to 90%, so the first overnight charge was to 100%...

That would not be my choice. When I am at home, I charge to 70%. If I take a road trip (multiple supercharger stops each way), I set it to 100% for the duration of the trip and forget about it. Mainly to maximize the supercharger duration while eating lunch somewhere. A somewhat passive means to avoid idle penalties. My travel rarely allows an overnight charge at the destination.
 

boaterva

Supporting Member
Apr 2, 2016
7,567
3,739
Northern Virginia, USA
Yeah, I’d like a way to have a permanent ‘normal charge setting’ (80) and then when you move it to 100 or 95 or something, it would spring back to 80 for the next charge unless you change it. Or have ones based on location for trips, or something a little more ‘smarter’.

As for the crashes, my X has never crashed while in use. It’s deep-sleeped when I didn’t expect it to, once or twice. I mentioned the overcharges, but the MCU never crashed on ‘its own’ (MCU1, of course).

TeslaFi does have settings for reminders for unplugged, if you are under this level, and if you are over this level, which can be set for any time of day, by location, etc. I’ve not used all of the options in the new Schedules and Reminder section, but James is constantly adding new features to it.
 

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