This can occur for three reasons
1) Please check that the insulating tape is not removed from the battery
2) There is something wrong with the charging power cord.
Tips: We recommend that you use a combination of the original charging cable and charging head.
3) Battery is faulty: Verify that other batteries charge properly. If not, replace the faulty battery.
Extreme battery temperature: Battery does not charge if the ambient temperature is below 5°C (41°F) or above 40°C (104°F).