Aside from the clipper attachment being insanely noisy, I’ve been happy with the Lingke 8806 3 in 1. Unfortunately, I shook it a bit too hard one day that the board got dislodged and charging became impossible.
I tried prying the case from the bottom and sides, but those were just cosmetic grooves. Prying the black part from the top was the correct way to open it. Removing two screws releases the motor and with it the board. Adhesive can be used to fix the board in place and/or add cardboard/plastic strips to wedge it in.
Forgot to take a photo of the battery itself, but it seems to be Li-ion 14500 3.7V.