The TOA BC-920 is a dedicated battery charger for BP-920 and BP-900A lithium-ion batteries used in the TS-821 and TS-921 Chairman units, and TS-822 and TS-922 Delegate units of TOA's Infrared conference system. The BC-920 features an exclusive charging system for lithium-ion batteries, and permits up to 8 batteries to be simultaneously charged within up to 5 hours.