I just bought a rechargeable battery pack and fully charged it. I can't seem to get my xbox to detect it. Everytime i press the wireless button on my console then the button on my controller, it then just gives a full 3 blinks i think on both console and controller but it doesn't show what player is is. Am I missing any steps? or there's something wrong with the batteries?

The cable by itself works but not with the batteries.

I went back to the shop today, the solution was to plug the cable in first so it detects the controller then place the battery in while the cable is still plugged in. Hope it helps anyone out there with the same problem. Cheers