Ryobi OP4040 40V 40-Volt 4.0 Ah Lithium-ion Battery & OP403 Charger W/ USB Port 46396027061 | eBay
Kobalt 40-Volt Max 5 Ah Rechargeable Lithium Ion (Li-Ion) Cordless Power Equipment Battery in the Cordless Power Equipment Batteries & Chargers department at Lowes.com
Ryobi Part # OP40602B-06VNM - Ryobi 40V Lithium-Ion 6.0 Ah High Capacity Battery And Rapid Charger Starter Kit (2-Batteries) - Outdoor Power Equipment Accessories - Home Depot Pro