The present invention provides a method for charging a NiMH battery, comprising estimating a state of charge of the battery (100), determining an end of charging time based on the estimated state of charge (200), applying a constant charging current with a rate in the range from 0.9 C to 2.1 C to the battery until a threshold voltage is reached (300), upon reaching the threshold voltage, applying a constant charging voltage substantially equal to the threshold voltage to the battery (400) and continuing applying the constant charging voltage to the battery until the end of charging time is reached (500). Furthermore, a battery charger adapted to perform such a method as well as a system comprising such a battery charger and a hearing device powered by a NiMH battery are given.