Posts: 14
Joined: Mon Mar 15, 2021 4:14 pm

Level 3 charging past 80%

Mon Mar 29, 2021 9:01 am

Is there any issues charging past 80% with the level 3 DC chargers?

I've been using Electrify America to charge on longer trips, and I thought its suppose to kick me off at 80% but it seems to keep going. I usually grab food while the car is charging, I manage to unplug the charger ta 92% but what happens if I'm late.. will the charger overload my battery if it goes past 100% or will it know to stop/slow down as it approaches 100?

Posts: 2424
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Level 3 charging past 80%

Mon Mar 29, 2021 11:34 am

DC fast charging even to 100% would not harm your i3. However, to protect its battery pack, your i3 would decrease the charging power so much that the time required to charge to a high charge level would no longer be described as "fast charging". In fact, it becomes no faster than AC Level 2 charging. So unless one absolutely must have a high charge level, most EV owners stop charging at 80% or maybe 90% for those EV's that don't decrease the charging power as much. It's also good etiquette not to occupy a DC fast charger to add the last bit of energy if some other EV is waiting. For those DC fast chargers that charge by time of use, that last 20% of energy would become very expensive.

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

Posts: 14
Joined: Mon Mar 15, 2021 4:14 pm

Re: Level 3 charging past 80%

Mon Mar 29, 2021 12:44 pm

Thanks. Make sense!

I notice the jump from 80% to 90% is still very fast.. Within minutes.. I barely have time to walk back to the car before its at 90%.

Good to know it will start to slow down drastically as it approaches 100%. Will definitely move it out. (Also Electrify America charges an idle fee so obviously would not want to pay money for nothing :)

Posts: 88
Joined: Sat Mar 07, 2020 6:15 pm

Re: Level 3 charging past 80%

Wed Mar 31, 2021 9:37 am

On my 2017 REx the charging rate seems to start dropping at around 95%. That's when I usually stop charging, especially when I'm at a charger where I pay by the minute!

Posts: 5196
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Level 3 charging past 80%

Thu Apr 01, 2021 7:02 pm

MOst places in the US charge by time rather than the energy put into the vehicle...so, since it slows down so much for that last little bit, it's often not cost effective to get to a full charge, but might be what you want, so you have to make the decision whether to continue to full or not.
Jim DeBruycker
2014 i3 BEV, 2021 X5 45e
(The i3 will be sold soon, <17K-miles, interested?)

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