Posts: 9
Joined: Mon Nov 18, 2019 2:33 pm

Hot while charging

Thu Oct 15, 2020 11:07 pm


I had an incident earlier in 2020 when the ambient temp of my garage was probably in the 50s or 60s (F). Nothing extreme for sure. I was charging my Bolt and left it plugged in for a while. I came into the garage and found that it was really really warm and the fans on the charger were running at full steam. At the time, I thought this was really bizarre behavior but never noticed it happening again. I don't recall what the percent charged was (probably 100%) but I'm certain that it was not too cold or too hot weather-wise. I've charged it since in much more extreme conditions and no fans came on at all.

I haven't given this too much thought until the news about the batteries catching fire. Has anyone else had anything like this happen? Any odd behavior with the thermal management system? I'm wondering if it could be related.

Again, I love my Bolt, and had it for just over a year now. I really hope that the GM engineers can root cause these fires, it would put me and my family at ease...


Posts: 106
Joined: Wed Sep 19, 2018 4:13 pm

Re: Hot while charging

Fri Oct 16, 2020 12:06 pm

I've heard my cooling fan come on a time or two (sounds like a jet engine) and I don't remember the garage being hot. If you're concerned, you can get torque pro and get readings on battery temp.

Posts: 47
Joined: Tue Jan 15, 2019 10:20 am
Location: SF Bay Area

Re: Hot while charging

Sat Oct 17, 2020 10:10 am

https://www.chevybolt.org/threads/batte ... ost-512173 describes the battery thermal management behavior.

Even WITHOUT the AC compressor engaging, when you AC charge, even 120 volts, the on-board charger will heat up. This is normal. Try charging for an hour or more then opening the hod and putting your hand on the OBC on the driver's side of the car. I've been driving BEVs are my primary car for over 7 years.

(OBC on Leaf also heats up, in Leaf's case it's the entire PDM stack (for model year '13+. For '11 and '12 Leafs, where the OBC was in the back under a plastic hump, I haven't felt it but it was also liquid cooled like OBCs on most/all other EVs.)

Posts: 4
Joined: Sun Oct 25, 2020 6:21 pm

Re: Hot while charging

Sun Oct 25, 2020 7:25 pm

My 2019 Bolt is currently on a level 2 240V charger. The garage is at 50F and the warmest anything is on the right hand (driver's side) of the engine compartment is 79F. There is a slight hum.

Posts: 4
Joined: Sun Oct 25, 2020 6:21 pm

Re: Hot while charging

Sun Oct 25, 2020 7:45 pm

Even last summer on 3day trip into hot eastern WA (85-95F) I never noticed cooling fans while running or using DC fast chargers except maybe once...? And the energy use screen never showed any energy use for "battery maintenance" or whatever it calls it.

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