I think he wants a charging circuit. There are 2 types of charging.
Fast charging uses charging controllers, the most popular being the MAX712/MAX713 series. They basically control the current used to charge the batteries such that overcharging, which may damage the battery, does not occur.
Trickle charging recharges battery by forcing a very small current into them, typically one-hundredth of their current capacity. This form of charging is very slow, but requires a minimal circuit.