The Ryobi 18v battery is a lightweight battery. Are you worried about the low power? No worries, the battery still performs as if it were fully charged. If you have a battery and want to use something right away, just plug it in.
The lithium-ion technology is used in the Ryobi 18v battery. It maintains full power output for its whole lifetime. Lithium-ion batteries don’t cause power loss over time. Instead, after the battery is completely discharged, the power output will immediately decrease from full to zero. In this case, the battery needs to be recharged. The battery pack need not be entirely depleted before being recharged.