It can be frustrating when a Dewalt 20V battery suddenly stops charging without warning. In many cases, the issue isn't with the charger but with the battery itself. One common reason is over-discharge—if the battery drains too low, the internal protection system may prevent it from recharging. Dirt or corrosion on the battery terminals can also interfere with the connection. Sometimes, users unknowingly store the battery in extreme temperatures, which can damage the internal cells. Faulty or old batteries may lose their ability to hold a charge over time. Always ensure you're using an original DeWalt charger and avoid third-party batteries that may not communicate correctly with the charging system.