Hey, I am new here and Am considering buying a Ryobi one+ starting kit that comes with two 18 volt batteries a charger and a drill.  I was wondering if you can use these regular 18 volt batteries (not the lithium) with any one+ tool from Ryobi even if it is intended to be used with a lithium battery.
Thanks

I don't know about that, since I don't use cordless drills very often, except for "egg-beater" styles.

I'd go with a lithium battery model. Lithium batteries charge faster (15 minutes on my Makita set) & last longer on a charge than regular ni-cad batteries.

I personally will never by another Ryobi product because I have 3 perfectly good cordless tools that I can't find batteries for. The Ryobi ni-cad batteries discharged quickly and with each charge lasted a shorter and shorter amount of time,  until they no longer took a charge. You eventually will need to buy new batteries but won't find any easily because Ryobi has changed battery designs every few years and the new batteries are not backwards compatible with the older tools.

I've had a Makita Drill & Driver lithium set for 2 years now, use it often and couldn't be more satisfied.

I have the complete Ryobi "plus-one" system. I have every tool they have that fits the batteries.

The older 18 volt batteries were ok , BUT the new Lithium batteries are 1000 percent better. They hold a charge 10 times longer after being charged and in the "ready". The lithium also charge much quicker. I now only have 1 older 18 volt ni-cad battery left, I have 5 of the "lithium" batteries, and they hold a static charge 10 times longer.
Be aware that the new lithium battery has to have the new lithium battery charger,,,, not the old ni-cad charger.
The new charger will also charge the older niCad batteries,,,,but the older charger will NOT charge the new lithium batts. OK??

Thanks! Do you know if you can power most 18 volt dwalt tools with the same battery and charger?

Sorry, but Dewalt Tools take their own battery and charger.
Also Ryobi takes their own battery and charger.
Like a Chevrolet engine part won't work on a Ford.
Two different companies competing against each other.