are there off the shelf circuit for charging batteries?

For example, you decides to use the rechargeable battery of a certain manufacturer, are there off the shelf charging solutions such that one doesn't have to design a battery charging/monitoring solution from scratch?

thanks

Google is your friend.

Adafruit sells a USB LiIon/LiPoly charger

i am looking for something like this but with auto cut functionality so that when external power source is there it should charge batteries and cut off batteries power to arduino mega .

okay, so I see that there are off the shelf charging circuits. I'm not necessarily going to use that Adafruit one. I need something that I can prototype with and use for mass production if I'm going to bring the device to market.

I wonder for projects that doesn't require much power, a Nickel Metal Hydrid battery might suffice? Lithium batteries are not as safe. Is NiMH batteries a lot safer?

A quick Google search found charge control chips available for $0.60 each. No Arduino necessary.

Paul

thanks