Can't do battery checks On my Sony Xperia E C1505, I can access the service menu via dialing *#*#7378423#*#*. If I then get to the tests menu, I can test the battery. However, the start level is at -1% somehow, meaning I can't do these tests as well. How do you get a device at -1% battery?

Why is this happening, and what can I do to fix this?
Couple of reasons:


The battery level is read from the  chip, which resides in the battery casing. It is probable that the chip has gone bad and can only be verified by replacing the battery
Less likely is that the fuel guage drivers which process battery information like voltage, current, temperature, NFC etc and in turn feed it to the other parts of the OS have been corrupted and only a factory reset or flashing stock ROM can help establish


Service center is always an option if you are lucky to find competent people