Backup Battery not working with PoE

So I was watching the official pro board installation video and Nate stated that while the board can be powered via PoE, that it is lower power then using the DC jack and that it would be totally fine to use both at the same time increasing the overall power. With this in mind, I have connected both power sources. The problem arises when I bought their backup battery and notice that it would not supply the board with power while the PoE was on (Power on light would be off). Would work just fine as soon as I disconnected PoE. This leaves me in a pickle as I was going to connect 2 tablets to the board for charging where my keypads use to be. Is there a solution to this?