If you are wanting to use it for tapping into the park, tapping ride photos that still have a touchpoint, and tapping in for Fastpasses, it will work fine. That part does not require battery power and will work indefinitely, as long as the band is active on your account. If you are wanting to use it for the long-range stuff like ride photos and things like the Small World Good-Bye Room (if working), unfortunately there is no way to test that out but to go on the ride and see if the photo shows up/long range feature work. There's nothing you can do from home to see if the battery is still good. In general they say the battery should last 2-3 years.