2manytools
Well-known member
I totally agree with you on Ryobi but DeWalt did make an 18v Li-On. It was out for a short time, before 20v. I have a kit from that era. The batteries are interchangeable with Ni-Cd without any adapter. I also have 20v and the adapter to go backwards to my 18v tools. Not sure what required the change to 20v other than pushing new brushless tools.
There was no change in the actual volts, just the marketing volts. If you look at the asterix near 20v on a Dewalt box, the fine print will say nominal voltage. Right after you start to use any "20v" tool, it drops to 18v almost immediately. That is why Dewalt was able to come out with that adapter, and probably made a hefty profit on it too.
It wasn't changing voltage, just the connection method. This is the exact same thing that allows you to take a Milwaukee/Makita/Dewalt battery and use it on a Ryobi tool so easily, just re-doing the connection. With 3D home printing, you could probably make your own any slide-style 18v pack to Dewalt post-style adapter pretty easy.
Like someone mentioned before, the reason for the switch from post-style to slide-style is it was a better form factor to build in. This does seem true, as all but Ryobi are in that style today. I think it has to do with it being easier to add more contact points on a slide battery, than on a post, while still having good contact pressure.

