I want to make a circuit that will control the charging of battery by using PWM. Can any one help me?

 

Welcome to AAC.
Is this a project?
If so show us what you have done already.

 

Why do you need to use pwm?

 

PWM is only needed if you really require a higher charging efficiency than a linear regulator can provide.
And you will need a feedback loop to control the current which is generally most easily done with an IC switching regulator chip.

 

I heard a friend said that there is someone in Taiwan that he applied a patent about the charging method, it seems used 90% to do the charging work and used 10% to do the discharge work, he claimed that is the best way for the batteries.

 

I heard a friend said that there is someone in Taiwan that he applied a patent about the charging method, it seems used 90% to do the charging work and used 10% to do the discharge work, he claimed that is the best way for the batteries.