TW200640102A - Efficient and safe charging device for Lithium secondary battery - Google Patents

Abstract

Disclosed is an efficient and safe charging device for Lithium secondary battery, for supplying electricity to the battery when the charging device is connected to a power supply. The charging device comprises (1) a counter unit (2) a clock (trigger) unit (3) a current-limiting unit and (4) a voltage comparison control unit. The clock unit generates a clock signal for controlling a counter signal of the counter unit, and the comparison control unit controls the current amount supplied by the power supply based on the counting status of the counter signal. At the beginning of charging, the charging device supplies only a tiny current to charge the battery, and the current is then increased slowly in accordance with the status of the counter signal until the counter signal stops changing. Afterwards, a current of the magnitude is supplied to charge the battery until it is full. The invention is characterized in that the amount of charging current is controlled by comparison of a counting logic during the whole charging process, and only a tiny current is supplied at the beginning of the charging process. The charging scheme prevents the battery from being damaged due to the instantaneously supplied surge current, thereby achieving faster and more efficient battery charging. Not only the service time of battery is made longer, but also the risk of over-heating caused by overcharging can be avoided.