Things I've learned abouit battery-powered tools and shop accessories:
-The hot ticket is to have both a 3/8-inch drive and a 1/2-inch drive battery-powered impact wrench. You'll always grab the smaller, lighter 3/8-inch tool first, simply because it's smaller and lighter. Unless you know you're going to be working with 3/8-inch (10 mm) or larger nuts and bolts. Then you might as well grab the larger unit because you'll probably need the extra torque.
-The key is to have battery-powered tools that all use the same type and size of battery. At one time I had four different tools that used four different kinds of batteries, requiring four different chargers. It's taken me several years and too much money to get things so all my tools share batteries. I wish I had done a better job of planning ahead.
-With commonality in mind, I now have my sights aimed for a battery-powered angle-head grinder and a battery-powered 3/8-inch ratchet wrench. I won't use the grinder for hard-core machine work---just for when I need to grind off a bolt head or touch-up a weld. The latest breed of battery-powered angle-head grinders work well as long as you don't need to grind non-stop for 15 minutes. The same applies to the battery-powered ratchet wrenches.
-Battery-powered lights are great but have a major downside, at least for me. The new generation of LED lights provide bright, white light akin to a 60-watt incandescent trouble light. They're great for working inside a machine or in awkward places because you don't have to route a power cord to them. Which highlights the problem I have with battery-powered lights: IF you happen to leave the light on so long that it's battery goes dead (generally 2- to 4-hours), there is no power cord to remind you that the darkened light is inside or under the machine. I've lost two battery-powered lights that way. Which may simply be MY problem because I'm forgetful, but...I had a tool salesman say that he's selling a lot of "second generation" battery-powered lights because his customers do the same thing I do, and lose the first lights they buy.
I may be forgetful, but I'm apparently not alone.