I got the Milwaukee 1/2” drill & 1/4” impact driver combo set a couple years ago.
They use the Lithium Ion 18v, 1500ah batteries and the set came with two.
I love this set, but it was the most expensive battery tool I ever bought at $200.
One warning, that little driver will twist the head right off a 3/8” hex bolt if you push it.
Ridgid has a similar set right now for about $179 and I believe they include the battery in the warranty.
Once you ever use a tool with a Lithium Battery you will never go back to Ni Cad.
A fringe benefit is the Li Ion can sit on a shelf for months and will hardly loose any charge at all.
It’s wise to consider what battery tools you might ever want in the future and after you have a set with batteries then you can add to the set with bare tools at a reduced cost.
But, be careful here, I bought a Milwaukee 18v circular saw thinking I already had the batteries I would need. Not true. the saw requires the bigger XL 3000ah battery which costs $100 by itself.
-- Michael :-{| Diapers and politicians both need to be changed often; and for the same reason.