According to an example, a battery is charged using a charge voltage based on a present state of charge of the battery and a present ambient temperature of the battery. Additionally, the charge voltage may be based on the present state of charge of the battery, the present ambient temperature of the battery, and an age of the battery. The charge voltage may be retrieved from a lookup table that includes a plurality of reference charge voltage values at which to charge the battery for different ambient temperatures, different states of charge, or different ages of the battery.