The charge light on the battery charger flashes when charging the battery pack

The CHARGE light may flash for the following reasons:

• The environmental temperature is too cold to charge the battery pack.
• The battery pack has not been used for a long time.
• There is a poor connection between the battery and charger.
• There is a problem with the battery pack.

The CHARGE lamp may flash fast (multiple times a second) or slow (around 1.5 second intervals), depending on the cause.

Slow flashing occurs if the battery has not been charged for a long time or if the environmental temperature is not suitable for charging the battery. The slow flash should stop after a short while or after the temperature returns to a suitable range between 50°F and 86°F (10°C and 30°C).

Fast flashing indicates a poor connection between the battery and charger or a problem with the battery pack. Refer to the rechargeable battery does not charge properly using the supplied battery charger article for details. Afterwards, try charging the battery again. If the flashing continues, then the battery may need to be replaced.