For UltraLITE, UltraLITE HD, HUB, and UltraPak systems Up to 6 hours of usage Approximate 3 hour charge time Works with Eartec's 2-, 8-, or 10-bay chargers The Eartec Rechargeable 3.7V Lithium-Ion Battery is designed for use with the UltraLITE wireless headsets, and HUB systems. This lightweight battery is about the size of a match book, and is installed directly into the headset. Since the battery is Li-ion, it doesn't need to be drained, nor will it develop memory issues.