Woot offers DEWALT DCB205-2 20V MAX XR 5 Ah Lithium Ion Battery 2-Pack Premium High Capacity Cordless Tool Battery Packs for $119.99 (reg. $249) free shipping with Amazon Prime. 

Product Description:
Power your 20V MAX* tools with these DEWALT 5ah 20v battery set that feature the runtime and performance needed for tough jobs. Keep your DEWALT 20V MAX Tools running longer with a premium 5.0 Amp hour Lithium-Ion DEWALT 20v XR battery packs. They provide up to 60% more capacity than a standard 20V MAX battery pack (DEWALT DCB200) The Lithium-Ion batteries have no memory and virtually no self-discharge for maximum productivity and less downtime.
 

• Reliable runtime. DeWalt 20v Max XR battery: take on tough jobs with DEWALT replacement batteries that deliver a 5ah capacity for consistent runtime on the jobsite
• State-of-charge - get quick visibility to your battery's state-of-charge with the LED indicator to help avoid interruptions. Offers 3 LED fuel gages to determine the charge
• Lightweight and Compatible: 20 volt DEWALT battery replacement weighing only 1.4 lbs, this battery is lightweight. Part of the 20V MAX* system - these batteries are compatible with 20V MAX* tools and chargers