Abstract: A method for managing electric quantity of a battery is disclosed. The method includes charging a battery normally with a 4.2V voltage when a temperature of the battery is lower than a first threshold temperature; charging the battery continuously when the temperature of the battery is higher than the first threshold temperature and lower than a second threshold temperature and the electric quantity of the battery is lower than a first threshold voltage. On the contrary, the battery is not charged any more when the temperature of the battery is between the first threshold temperature and the second threshold temperature and the electric quantity of the battery is higher than the first threshold voltage or a first capacity. If the temperature of the battery is higher than a second threshold temperature, the battery is not charged any more regardless of the battery voltage.

Abstract: The invention discloses a pointing device comprising a first sensing unit, a second sensing unit and a processing unit. The first sensing unit is utilized for sensing a first rotational angle of the pointing device relative to an absolute coordinate system. The second sensing unit is utilized for sensing a second rotational angle of the pointing device relative to the absolute coordinate system. The processing unit is utilized for receiving the first and second rotational angles, calculating an absolute difference between the first and second rotational angles and judging whether the absolute difference is smaller than a predetermined threshold. If it is YES, the processing unit outputs the first rotational angle; otherwise, the processing unit calibrates the first rotational angle by the second rotational angle and then outputs the calibrated rotational angle.