The present invention provides a 
fast charging method for battery, including the steps as follows: (1) the battery is charged with a 
constant current I1 and the charging time is t1; (2) the battery is charged with a 
constant current I2 and the charging time is t2; (3) the battery is discharged with the 
constant current I2 and the discharging time is t3, recycling until the 
voltage reaches a pre-charging 
voltage of battery; (4) the battery is standed after the 
voltage reaching the pre-charging voltage of battery, and the 
rest time is t4, and then the battery is charged with a constant current I3 until the voltage reaching a 
cut-off voltage of battery, and then the battery is charged with a 
constant voltage until the current reaching a 
cut-off current I4; wherein, I2<I1, t2<t1, t3<t1, I2<I3≦I1, I4≦I2. The 
fast charging method provided in present invention can decrease the polarization in pulse charging phase, increase the time of whole pulse charging phase, improve the charging speed in pulse charging phase, and thus shorten the full-charging time.