I use Ryobi as they kept the same battery style when transitioning from Ni-Cad to Li-ion 18V and there's lot of third party suppliers of battery pack sso my three 20+ year drills and screwdrivers are still in use (currently have six battery packs) unlike other manufacturers where the battery pack died and was more expensive to replace than buy a new drill and battery as the new drills changed the battery pack style which were not compatible with older drills (Dewalt, Bosh Black and Decker and others to mention but a few)