Shure SB902 Rechargeable Lithium-Ion Battery for GLX-D Spare SB902 Rechargeable Lithium-Ion Battery for your GLX-D Wireless Component or System Lithium-ion battery serves either as a replacement or a spare battery to charge while using the system Up to 16 hours of continuous, rechargeable use Up to 13,000 hours of regular use per individual custom lithium-ion battery (Compared against up to 2,000 alkaline batteries) 3 hour charge = up to 16 hours use, 1 hour charge = up to 6 hours use, 30 minute charge = up to 3 hours use, 15 minute charge = up to 1.5 hours use