Battery type - liquid lithium ion battery ( 18650)
Product size - 57mm point x 28mm
Screen size - 27mm x 17mm.
The circuit board is connected to the battery negative B-, B + is positive, no connection is reversed,
the connection twist will burn the board, the battery is connected in parallel to solder, and the
battery is assembled. Please note that the insulation between the battery and the circuit board,
the battery leads should not touch the circuit board to avoid short circuit.