I will revive a thread a little bit as I got new batteries for two units and have been struggling to get them calibrated. Disabling both the bq27x00 and rx51 battery modules does't seen to prevent the device to shut down automaticly I think the bnf is doing this.

Although I've calibrated one battery after voltage dropes somewhere below the 3248 and device shut down (Not fainted) I recharged it with both mentioned modules In -r mode and now it is working fine with bq27x00 module.

The second one (Same new battery, same manufaturer) show that it's got 868mAh, charge to 660 (Each and every time) and got discharged in very slow way. Battery seems to have good, original capacity but I've found no way to calibrate it.

I will try it later with some scripts I need to work on first without the bnf. We will see.