This paper presents a new Li-Ion battery charger using charge-pump techniques. It has small chip size and simple structure. Besides, the proposed charger provides basic functions with voltage and current detecting, end-of-charge detecting and automatic charging speed control. The charger is operated in mixed method and supported from trickle/large constant-current mode to constant-voltage mode with different charging rates. This charger is implemented in TSMC 035Ztm CMOS process with 5V power supply. Its output voltage is over or equal to 4.2V and maximum charging current reaches 700mA. It has 837mW chip power dissipation and 67.89% power efficiency and chip area is 1.455 x 1.348 mm2 only.