What is this setup? Eg powering down the processor does not power down the usb to tty (atmega8u2) or other components, your battery discharges faster than the power the processor consumes...
I'm making a standalone Arduino project where the Arduino is sleeping when not required, otherwise it is awake. One of the Arduino pins controls a LED array of 400mA. The board is powered by a 3.7V lipo. The attached circuit shows how i will hopefully control the LED part.
If you can handle soldering the microscopic stuff, go for.
I can't see well enough to do stuff that small.
At least the first part had a workable form factor.
Thanks for your responses. This is actually part of a larger project that I will eventually get developed in a PCB. I will go with the last mosfet I mentioned and hopefully everything is ok.