tolerance of voltage for beagle bone black

Hi,

We are using beagle bone black for our project and we are powering it by 5V adapter. We would like to provide a 5V battery backup from the jack port which is adjacent to the adapter socket. What is the tolerance of this jack port. I mean what is the minimum and maximum voltage that can be supplied to the jack without damaging the BBB.

Thanks.

Lower than 5V that will not damage the board. But if you want the USB port to work, you need 5V.

Gerald