Hello all, I'm working on a microcontroller project that will normally be running on a "wall wart" power supply plugged into a wall outlet in my home. I'd like to build a UPS such that the controller runs on a batter if/when the wall wart fails or loses power. The controller has a 5v regulator onboard and will probably need a few hundred mA, worst case. Runtime requirement isn't really set in stone; an hour (or several hours) would be fine. This had led me to consider a small number of NiCd or NiMH cells for the backup battery. What I need help with is designing (or finding, I'm sure there's something out there) a circuit that will do the following: 1) Under normal operation when the wall wart is supplying power, manage the battery (i.e. fast charge if it's down, overcharge prevention, trickling to keep it full, etc) and run the controller on the wall wart. 2) When the wall wart goes down, switch to battery backup. I see ICs out there like this: http://www.mouser.com/ProductDetail...GAEpiMZZMsfD%2bbMpEGFJW8KB1dw6TbhUWor9lDc7TE= that sort of look like they were intended for this purpose, so I think I may be on to a solution already, but would like some verification from people who have done this sort of thing before.