Charging failure is a condition where a battery does not accept power from its charger. The battery may be deeply discharged, the charger may be faulty, or an internal protection circuit, fuse, connector, or cell may prevent normal charging. In the Makita battery-pack context, the visible symptom was simple: the pack would not recharge until a small internal part was replaced.
In cyber security, charging failure matters because many security and industrial systems depend on battery power: radios, access-control units, cameras, sensors, handheld tools, and backup supplies. A device that cannot charge can stop logging, disable alarms, interrupt incident response, or create blind spots in physical security. Defenders look for charging failures as signs of wear, bad firmware, damaged power paths, or tampering. Attackers can exploit the same weakness by damaging batteries, blocking charging circuits, or forcing devices offline, so basic power-path diagnostics and serviceable battery design are part of resilience.