Abstract: A secondary electrochemical battery sealing body, including a negative electrode cap, a circuit board module and an insulating washer. The circuit board module is connected to the negative electrode cap via a connecting member. A charge indicator is disposed on the circuit board module at the position corresponding to an edge of the negative electrode cap. A notch is formed on the edge of the negative electrode cap as a light transmission port of the charge indicator. The notch has a height which does not exceed the height of the negative electrode cap. The insulating washer is a flexible and elastic annular insulating gasket, and is disposed in a gap between a battery housing, the circuit board module and the negative electrode cap. The insulating washer completely covers the light transmission port of the charge indicator to seal the negative electrode cap, the battery housing and the circuit board module.