This disclosure describes techniques for a method of charging a battery. In an example, the method includes determining a capacity of the battery, and determining a state of charge of the battery. The method also includes charging the battery with a charging current, wherein the charging current is based on the capacity of the battery and the state of charge of the battery, and wherein charging the battery comprises reducing the charging current in response to the state of charge of the battery changing with respect to the capacity of the battery.