Ryobi's regular 40V batteries are designed for use ... but it appears that the batteries are entirely interchangeable. This means you should be able to use your old 40V tools with the new 40V ...
Unfortunately, it's not perfect, as not all tools and batteries are interchangeable. For example, if you have a 40-volt Ryobi ...
If you're a fan of cordless Ryobi power tools, you may have wondered what the difference is between the HP and non-HP tools.