A 5.0 Ah Lithium+ battery supplied with a ONE+ charger, so you have a working power source for any tool in the system. The charger works with every 18V ONE+ Lithium-ion battery. Indicator lights show status while a battery charges and while it is being maintained, and a separate indicator shows when the pack has reached 80% capacity and is ready to use. Intelligent condition monitoring checks the battery's voltage and temperature during charging. Battery system: ONE+ is Ryobi's 18V platform — one battery fits over 200 tools for house and garden.