A method for charging a battery, in particular a lithium ion battery, be performing the following: charging the battery using a constant charging current in a first phase, charging the battery using a constant charging voltage in a subsequent second phase, ending the charging as a function of a specifiable boundary value of the charging current in the second phase. In this context, the following operations are provided: comparing a guide voltage specified for setting the constant voltage to at least one stored switch-off value determined as a function of the boundary value, and ending the charging when the guide voltage reaches the switch-off value. Also described is a device for charging the battery.