A method, a battery, and a system determine an amount of degradation of the battery. The method includes providing an autoclaveable lithium battery for a medical device, receiving a charging signal from a charging device, and initiating a charging cycle to charge a cell of the battery based on the charging signal. The charging cycle includes a constant current phase and a constant voltage phase. The method also includes monitoring a current provided to the cell during at least a portion of the constant voltage phase, calculating a current taper time based on the current provided during the constant voltage phase, and determining an amount of degradation of the battery based on the current taper time.