For a portable device i have the following battery management circuitry:
I'm using the MCP73871 for charge management and power oring and the BQ2972 for over discharge protection. If VBUS is connected, the left NMOS gets switched on and the battery is connected. If VBUS is not connected, the left NMOS is initially switched off. When the pushbutton gets pressed for a short time now, the device is powered up and a mcu can keep the NMOS switched on via Bat_Connect (and switch it off too).
So far the theory, but does it work like this, is there a simpler/better solution i'm not aware of?
EDIT: Top pin of the connector is bat+, middle is thermistor, bottom is bat-. I suppose the pulldown resistor of the left NMOS should not be connected to GND but rather to bat-/drain of the right NMOS.