METHOD FOR CHARGING A RECHARGEABLE BATTERY OF AN ELECTRIC DEVICE

A method for charging a rechargeable battery (3) of an electric device in different charging steps applying different charging currents is described, said charging steps comprising at least: - a first charging step applying a first constant charging current (I1) to the battery (3) while the battery voltage is smaller than a first voltage threshold (V1) and/or while the battery temperature is smaller than a first temperature threshold, said first charging (I1) current being smaller than a second charging current (12); - a second charging step applying said second constant charging current (12) to the battery (3) while the battery voltage is higher than said first battery voltage threshold (V1) and lower than a second battery voltage threshold (V2) and/or while the battery temperature is higher than said first temperature threshold and smaller than a second temperature threshold; - a third charging step applying a constant charging current (I3) to the battery (3), wherein said third constant charging current (I3) is switched on every time when the battery voltage drops to a fourth voltage threshold (V4) and switched off when the battery voltage reaches a fifth voltage threshold (V5), and wherein said third charging step providing said repeated switching on and off the third constant charging current (I3) thereby producing current pulses ends if the length of a current pause (Toff) following said current pulse (Ton) equals or exceeds the length of p·(k-1)-times the preceding current pulse (Ton) with k being the ratio of constant charging current 13 and the constant charging current I1 and p being a defined factor. (Fig. 2)