At Home Depot, buy two select Ryobi ONE+ 18-volt Bare Tools and receive the Ryobi ONE+ 18-volt Lithium-Ion Battery and IntelliPort Charger Upgrade Kit, model no. P128, for free. (Add all qualifying items to your cart and the discount will apply at checkout.) Orders of $45 or more receive free shipping. (Alternatively, opt for in-store pickup to avoid shipping fees beginning from $5.99.) That's a savings of $59 and the best deal we could find. The battery works with a number of Ryobi ONE+ cordless tools. Deal ends April 27.
Note: Qualifying tools are indicated below the price field.