My new D4 developed a weird battery issue (it wouldn't charge past 50%) after 3 months, so Vzw sent me a "certified like new device". Said device's battery life was half the new one (6 hours vs 12). A tech sent me another like new device yesterday and the battery life is the same. Obviously, they're keeping the trashed batteries on these remanufactured devices. I plan to demand a brand new device this afternoon.