Battery Management System (BMS) Reset

Thread Starter


Joined Dec 19, 2019
After many months of not using my Asus EeePad TF101 I have turned it on by plugging in the charger.

After the boot the battery was 0% and I wasn’t surprised about this as I have not used the tablet for many months.

I tried to charge it like before but after few hours it was still 0%.

I found online that when the battery drops to 0% then it won’t charge anymore and needs to be replaced.

The battery is 7.4V 3300 mAh, 24Wh, Li-Polymer C21-EP101

I have taken the battery apart and it turned out that it consists of 2 smaller batteries each 3.7V, 11.87Wh but the voltage was in mV so they were fully discharged.

I have unsoldered them from BMS and charged them separately using a different charger for about 20 min.

After that the multimeter showed correct voltage’s (around 3.7V) so the batteries were charged at least few percent.

Then I’ve soldered the batteries back to the BMS and put it back in the tablet.

After powering the tablet, 3% battery charge was shown but still the battery wasn’t charging.

Voltage to the BMS was about 4.7V so BMS is blocking charging the battery, just as I found info online about the discharge issue.

Is there a way to reset BMS to start charging the battery again ?

or it needs to be replaced ? If so any idea which BMS replacement will be good in this case ? (the original one has a temperature sensor)

Many thanks