Hi,
I am designing a device that must work from external power when plugged in, when it is, it must charge the internal battery. When it is unplugged it should run from battery power.
I have included a sketch of a design I have come up with. What do you think? Have I missed any better ways to do this? I'm not that excited about the relay, but it seems simple and foolproof.
The microcontroller runs from the battery directly so it can turn on and off the peripherals as necessary.
Any and all comments are gratefully received.
R