Patent ID: 7715161

Claim:
A device comprising: a storage portion for storing electrical energy; and an auto-shut-off portion for monitoring an output current from the storage portion and which includes a controllable first switch by which the current output can be interrupted; wherein said controllable first switch is adapted to being opened and the current output being therefore interrupted when the auto-shut-off portion for monitoring the output current detects, that for a predetermined time, the current output does not fluctuate or only slightly fluctuates; wherein the auto-shut-off portion can be switched off by means of a second switch while continuing to allow power to be provided to an electrical device; wherein the auto-shut-off portion further includes a capacitor which determines the predetermined time; wherein the auto-shut-off portion further includes: a diode; a resistor; and a comparator with first and second inputs; wherein current fluctuations are allowed through to the diode, the capacitor, and the resistor of the auto-shut-off portion; wherein the predetermined time is determined by the capacitor when the current fluctuations decrease to a point so as to fall below a specific threshold value; wherein an output of the capacitor is connected to the first input of the comparator, the comparator carrying out a comparison of a value received from the first input with the threshold value, which is received from the second input; and wherein a switching-off signal is sent to open the controllable switch when the comparator determines that the value received from the first input is less than the threshold value received from the second input.