WorxGT via eBay offers the Worx 18-volt Lithium-Ion Battery, model no. WA3512.1, for $39.99 with free shipping. That's the lowest total price we could find by $35. This battery is designed to work with Worx cordless powered models WG151, WG251 and WG540, and purportedly has thrice the useable life of standard Ni-Cd batteries. Deal ends September 28 at 11:35 am ET.