Few years old, lightly used(not in a shop). Shows 3 battery bars then quickly goes to 4 bars(full) battery. Will turn on if plugged in, turns off as soon as I unplug it. I'm guessing a dead battery? Opened it up, Seems to be a 18650 with a little PCB. Anyone had any luck replacing this? I don't see it in the repair parts on the website, will probably have to go with something off aliexpress or weld a new 18650 in?
