Working on a job yesterday and I had two separate faulty TB50s which took two paired sets out of action out of a total of five pairs (Just about managed running on three pairs). The App reported "Battery Cell Error".

Checked the faulty batteries and it was clear that one cell in each had gone to ~4.34v and a significant voltage difference between the cells.

Since then, I've discharged the faulty batteries to <4% and recharged them, but the fault still exists. I can't fly the batteries becuause GO denies flying on this error, so it's a very slow means of discharging by leaving the i2 running for hours, which I hate doing.

One battery is on 7 charge cycles, the other on 15.

Anyway, I'm really worried about this, as this is two separate TB50s, bought at different times (and countries) and they both failed on the same day.

I'm going to set up a support ticket, but keen to hear of any similar issues, as I couldn't see much on the forums about this.

I've had the same problem with 2 batteries but a month apart. The first one I was advised by DJI support to drain the battery to 5% and recharge it. It did not clear the error. They exchanged the battery and I paired a new one with the orphaned battery at 15 cycles. The next time it happened on a different set I didn't call right away and experimented. There was no cell reading over voltage. If I placed the good battery of the pair in the right bay and start up before putting in the supposed bad battery it would not give an error. This time I called DJI and they seemed to laugh at me and say that I'm past my 6 month warranty. The battery manufactured 1/2017 has 20 cycles. I'm wondering if this is more of a firmware issue or if I can swap the pairing of 2 sets as a test.