PWM Charge Controller

It is hard to answer your question since the circuit diagram is not clear and at places faulty. Why do you have two switch Q1 and Q2 and what is the operating voltage and frequency. Also does that simple driver circuit work? Have you tested it? I think you will need a mosfet driver IC for this 

The circuit works perfectly and we do not need a driver IC as it is P Channel MOSFET. I have tested it out. Q1 is for charging a battery and Q2 to drive the load. The circuit is alsoperfectly okay and not faulty. Operating voltage is bwtween 12-24V and frequency is 50KHz.

A series charge controller or series regulator disables further current flow into batteries when they are full. A shunt charge controller or shunt regulator diverts excess electricity to an auxiliary or "shunt" load, such as an electric water heater, when batteries are full.

Simple charge controllers stop charging a battery when they exceed a set high voltage level, and re-enable charging when battery voltage drops back below that level.Pulse width modulation ( PWM) and maximum power point tracker technologies are more electronically sophisticated, adjusting charging rates depending on the battery's level, to allow charging closer to its maximum capacity.

A charge controller with MPPT capability frees the system designer from closely matching available PV voltage to battery voltage. Considerable efficiency gains can be achieved, particularly when the PV array is located at some distance from the battery. By way of example, a 150 volt PV array connected to an MPPT charge controller can be used to charge a 24 or 48 volt battery. Higher array voltage means lower array current, so the savings in wiring costs can more than pay for the controller.

Charge controllers may also monitor battery temperature to prevent overheating. Some charge controller systems also display data, transmit data to remote displays, and data logging to track electric flow over time.