"No data or battery not calibrated" 3 days after a calibration
 

I bought a used N900, groomed it, soldered the USB port and now started using it.

After installing CSSU with BME replacement I got a "No data or battery not calibrated" message.

So I calibrated the battery, had a 3 cycles of charging, left the device for the night to charge. I just woke up and saw: "No data or battery" not calibrated. After a reboot the device died from too low battery level.

Can somebody tell me why the device stopped charging out of nothing with the "battery not calibrated" msg?

Running bnf after a reboot (this time being plugged into charger) said the battery doesn't need calibration.

Another "feature" of bq27x00? [The first "feature" is the fact that bq27x00 doesn't give any meaningful info if the battery's not calibrated, forcing the user to walk in the dark]