M12 12-Volt Lithium-Ion Compact and Extended Capacity Battery Combo with Four 2.0 Ah and Four 4.0 Ah BatteriesThe Milwaukee M12 REDLITHIUM CP 2. 0 & XC 4. 0 batteries deliver up to two times more runtime, 20% more power and two times more recharges than standard lithium ion batteries. The rechargeable battery also delivers 2. 0 Ah of runtime. The extended capacity battery delivers 4 Ah (48 watt hour) of run time, even in sub zero temperatures. The lithium ion battery pack features superior pack construction, electronics and performance to provide more work