Since UltraLITE headsets feature self contained, "All in One" design all electronics, even the battery, is installed in the headset plastics. The batteries are lightweight and about the size of a book of matches. They charge in about 3 hours, run for 6 hours and can be changed out in seconds. Since they are Li-ion, the batteries do not have to be "drained" after each use and will never develop a memory.
Eartec 5 Pack 3.7V Rechargeable Lithium Ion Battery - Eartec 60 Day Warranty