Woot offers Milwaukee 48-59-2424P M12 REDLITHIUM CP2.0 & XC4.0 StarterKit for $69.99 (orig. $116.39) free shipping.

Product Description:
M12 CP 2.0Ah & XC 4.0Ah Battery and Charger Starter Kit TheM12 charger accepts all M12 batteries, so you will always be preparedand productive. The career communicated directly with the battery packto monitor cell voltage, temperature and charge status to ensure a fullcharge. Power up your compact batteries in 30 minutes and extendcapacity batteries in 60 minutes, without the need for extra charges onthe jobsite.
The Milwaukee 2.0 provides up to 2X more run-time, 20percentage more power and 2X more recharges than a standard lithium-ionbattery. 2.0 also delivered best-in-class performance in extremejob-site conditions. With Milwaukee durability built into each pack, the2.0 battery operates cooler and performs better in climates below-18-degree C/0-degree F with fade free power.