This battery charger with PSU will charge 1 receiver module (IRR-NL23 or IRR-ST95) and up to 2 additional battery cells (BAT-01). 

The receiver can be placed into the battery charger receiver port without removing its battery cell.  Battery cells can be placed into the battery charger battery ports.

The cells are environmentally-friendly Nickel Metal-hydride batteries, which in normal use will provide about 6 hours of continuous use per charge and have a life-expectancy of up to 3 years.

Normally an exhausted battery would be fully re-charged after an overnight charge in the battery charger.