Yes, you absolutely can. That's the whole point of the ONE+ system. Your Ryobi P215K1 drill driver is designed to work with all 18V ONE+ Lithium+ batteries.
Here's what you need to do:
- Take your older ONE+ 18V battery.
- Slide it into the battery port on the bottom of the drill's handle. It should click firmly into place.
- You're ready to go. The drill will draw power from it normally.
The system is backward and forward compatible. You can use old batteries on new tools and new batteries on old ONE+ tools. The performance you get will depend on the capacity (Ah rating) of the older battery. A newer, higher-capacity battery will generally provide longer run time and can deliver more power for demanding tasks.
IF THAT DIDN'T WORK: If the older battery doesn't click in, check that it's an 18V ONE+ battery, not a battery from a different Ryobi platform (like 36V). Also, inspect the contacts on both the battery and drill for any obstructions or corrosion. Clean them with a dry cloth if needed.
HEADS UP: The electronic protection system in the tool and battery will still work with older compatible batteries. It protects against overloading and overheating.