Update code and charge lipo battery?

Has anyone created a design whereby they can charge a lipo battery through the mini USB on the Arduino (Nano for example)?

I'm wanting a system where I can update my code AND charge a 3.7v Lipo battery through the same USB.

thanks

You cannot source current from the USB connector on an Arduino board

ok,
]

How about if I changed the Arduino for an AtTiny 85?

Has anyone created an updater/lipo charger from the micro usb for this kind of setup?