I am trying to purchase some rechargeable 9V for our Shure ULX wireless mics. I am looking at getting 2 Powerex MH-C1090F Pro 10-Bank Rapid 9V NiMH Battery Charger and the Powerex 9V Precharged Rechargeable NiMH Battery (9.6V, 230mAh). I dont know too much about mics- but I was told this was a good charger and battery to get for this mic. What concerns me is the mics take a 9v battery but the batter is a 9.6. Is this okay? Or do I need to go to the 8.4v?