A cordless power tool battery pack including an onboard circuit configured to electronically communicate with an associated battery charging system and an associated battery analyzing system. The onboard circuit communicates information relating to the battery pack to a microprocessor or the like within the battery charging system and charging of the battery pack is controlled based on such communication. The onboard circuit also communicates information relating to the battery pack to a microprocessor or the like within the battery analyzing system which can than be communicated to an interface unit for display to a user.