2 x 18V 5.5Ah BL1850B Batteries. Charging Current: 6A (UK plug). Lightweight: 40% lighter than traditional Ni-Mh batteries. Compatible with BL1830, 14.4V-18V Batteries. Warm Note: Batteries may heat up after use - allow 15-20 minutes to cool before recharging for optimal performance.
eBay