||If the charger is showing a single Red flashing LED, this is normal. The charger is evaluating the battery pack and will begin charging once evaluation has finished. If the charger is showing both a Red flashing LED and a Green flashing LED at the same time then there may be a fault with either the charger or the battery pack.
If you are having problems with the BCL1418H battery charger please follow the link below:
Charging a Ryobi 18V Battery Pack