Thin-film battery protection

The protecting method involves periodically operating a thin-layer battery (11) at its maximum discharge current, and disconnecting the battery as soon as a voltage across it reaches a threshold value greater than its critical voltage for the maximum discharge current. Preferably, the periodic operation has a duty cycle smaller than 0.1%. Preferably, the duration of each phase of the periodic operation is shorter than 10 milliseconds. An independent claim is also included for a protecting device for thin-layer battery connected to intermittent load.