For in-store pickup only and with availability determined by ZIP code, Home Depot offers the Ryobi ONE+ 18-Volt Lithium Battery 2-Pack, model no. P122, for $99. That's $66 under the best shipped price we could find elsewhere. These batteries purport to provide four times more runtime, four times longer lasting charge, and 20% lighter weight than regular Ni-Cd batteries.

Update: Pad your order over $100 (this lock nut costs $1.18) and apply coupon code "SPRINGHD" to cut it to $89, excluding the cost of padding.