I need complete details of Battery charger because i need to do a project on it..

Battery charger
A battery charger is a device used to put energy into a secondary cell or (rechargeable) battery by forcing an electric current through it and the charge current depends upon the technology and capacity of the battery being charged. They are entirely different for a car battery and a Ni-Cad battery.

Types of battery chargers
1)Simple
works by supplying a constant DC power source to a battery being charged. The simple charger does not alter its output based on time or the charge on the battery.a battery left in a simple charger for too long will be weakened or destroyed due to over-charging.

2)Trickle
A trickle charger is a kind of simple charger that charges the battery slowly, at the self-discharge rate. A trickle charger is the slowest kind of battery charger. A battery can be left in a trickle charger indefinitely. Leaving a battery in a trickle charger keeps the battery "topped up" but never over-charges.

3)Intelligent
Here, the Output current depends upon the battery's state. It may monitor the battery's voltage, temperature and/or time under charge to determine the optimum charge current at that instant. Charging is terminated when a combination of the voltage, temperature and/or time indicates that the battery is fully charged.

4)Timer-based
The output of a timer charger is terminated after a pre-determined time. If batteries of lower capacity were charged then they would be overcharged, and if batteries of higher capacity were charged they would be only partly charged.

5)Pulse
Here, a pulse having a strictly controlled rise time, pulse width, pulse repetition rate (frequency) and amplitude is fed to the battery. . This technology is said to work with any size, voltage, capacity or chemistry of batteries, including automotive and valve-regulated batteries.

6)Fast
make use of control circuitry in the batteries being charged to rapidly charge the batteries without damaging the cells' elements. Most such chargers have a cooling fan to help keep the temperature of the cells under control.

7)Inductive
This uses electromagnetic induction to charge batteries. A charging station sends electromagnetic energy through inductive coupling to an electrical device, which stores the energy in the batteries.

For more, visit this link:
http://en.wikipediawiki/Battery_charger

Some of the battery charger circuit digrams can be found in this link:
http://educypedia.be/electronics/circuitsbattery.htm

serach the net for more circuits and details!