Recently I experienced a full discharge on my battery where it rapidly dropped to 0.14v. And said in another post I would document the behaviour.
At the time of discharge the Arduboy was connected to usb and shortly after uploading a sketch the bottom half of the screen garbled and then the Arduboy switched off.
I immediately thought I had corrupted the bootloader to find the Arduboy booted and run fine when connected to an ISP programmer, at this stage I grabbed my multimeter to find the battery depleted and refusing to charge.
The Arduboys charge led will not switch on unless the Arduboy is turned on but the unit itself will not power on.
Jumping the Battery + terminal to Vcc will allow the unit to boot from usb power
connecting a second Lipo in parallel also allowed the unit to power on and charge whilst this allowed some charge to enter the battery it wasn’t any significant level.
the battery will not take a charge from another Lipo charger I have but will increase to 0.34v on a lithium Ion charger but this rapidly depleted.
I’m yet to hack up a NiCd/NiMH charger to try get it up to 3v but it’s been few days so it’s probably too late.
I’m not 100% certain what caused the battery to drop but I’m guessing it’s possibly something to do with leaving a mpu6050 connected via i2c for a long period but thought this would be fine due to the battery protection circuit.
For now the old warrior lives on to fight another day with a salvaged micro drone battery.