If the night fishing light is not used for a long time, it should be recharged at regular intervals. This is the case for batteries that have been exhausted for a long time.
The battery will be like this after being used for a long time, just like a cell phone battery.
The remedy is to replace the battery with a new one, or simply replace the light.
Charging settings vary depending on charger model. Sanqianyuejia lithium battery charging parameters: input is 110V-240V, power is 4.2V2A, indicator light is red when charging, green when fully charged, interface 3 .5mm x 1.35mm