1. The voltage and current of the charger do not match your battery. You have purchased a charger with wrong parameters. Please tell us the brand and model of your electric bike or the parameters and plug of the original charger.
2. Due to the limited life of the lithium battery, the charger will not work if the battery is damaged. Your battery may be damaged if it is not used for more than 12 months or 2-3 months.
3. If the green light comes on when the power is turned on, but the LED light does not turn red after the battery is connected, the connector should be loose and in poor contact, and the plug can be re inserted to maintain good contact
4. If there is a green light when plugged into the power supply, and the light goes out after connecting the electric bicycle, it is because of the internal short circuit of the electric bicycle, which causes the charger to have a self-protection function. You'd better check your e-bike battery and replace it