Ryobi P102  18V One+ Compact Lithium Ion Battery, 2 Pack COMPACT DESIGN: This compact Ryobi 18V Lithium Ion battery line gives you lighter weight for improved tool handling LIGHTER WEIGHT than most other batteries in the Ryobi system prevents user fatigue ONE+ COMPATIBLE: This battery works on all One+ compatible Ryobi power tools, from the string trimmer to the reciprocating saw to the drain auger IMPROVED BATTERY LIFE over older NiCad models. Up to 4x more runtime FADE-FREE POWER: Dont worry about your tools getting weaker as the battery drains. With this, youll be able to work at full power until the juice runs out