Lowes offers CRAFTSMAN V20 20-V 4-Pack Lithium-ion Battery and Charger (1.5 Ah) for $79 (reg. $149) free shipping.

Product Description:
The V20* Dual Port Charger and 4-Battery Kit charges two batteries and a USB-compatible device (2.1 Amp max output) simultaneously, giving you the power to complete your DIY projects. The Kit includes 4 V20* 1.5Ah batteries with a V20* Dual Port Charger and is equipped with LED charging indicators that provide immediate state-of-charge feedback, so you can stay ahead of your power needs.