RYOBI ONE+ 18V 4.0 Ah Lithium-Ion HIGH PERFORMANCE Battery PBP004 - The Home Depot
RYOBI ONE+ HP 18V Brushless Cordless 10 in. Sliding Compound Miter Saw Kit with 4.0 Ah HIGH PERFORMANCE Battery and Charger PBLMS01K - $161.52 w/hack, $269 at Home Depot