Battery won’t charge past 99% and won’t stop charging

StuckintheSpokes

Finding my (electric) wheels
Feb 5, 2019
14
0
I left it on 99% for about 30 minutes and it wouldn’t stop charging. Do I need to keep an eye on the battery when charging it from now on?
 

russ18uk

Pedelecer
Sep 18, 2018
71
23
Makes no difference. Balancing could takes hours or even a day or more if a cell has drifted.
 

StuckintheSpokes

Finding my (electric) wheels
Feb 5, 2019
14
0
Well after an hour more on charge the battery managed to get to 100%. The next time I charged it, same problem. From now on I think as soon as it reaches 99% I’m going to unplug and get on the bike.
 

wheeliepete

Esteemed Pedelecer
Feb 28, 2016
2,047
755
60
Devon
99% is fine, you are not going to notice any difference in range, but it's prob. a good idea to leave to reach 100% every 5-6 charge cycles to prevent the battery going out of balance. Depending how old your battery is, it could be a sign the cells are beginning to lose capacity. You see the same thing happen to laptop batteries.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,991
8,173
60
West Sx RH
At 99% battery is balanced, likely only time imbalance will occur is if you only charge to 80/90% then the BMS will not even think about it or a BMS bleed resistor fails.
 

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