We have two Xbox 360 controllers and a total of three rechargeable battery packs for the two controllers. Can anyone tell me how long it should take for the battery to fully charge, if you're NOT using it while it's charging? Also, how long should the charge last before it needs to be recharged again, assuming you turn the controller off when you're not using it? Last, how long will the battery itself last before it stops taking a charge and has to be replaced?