Don't remember the exact specs on the metabo 1/2 cordless impact gun I have, but it's 18V and can be charged up completely in 30 minutes or less. It takes care of the lug nuts on my 8 lug trucks and I've used it at the wrecking yard too, pulling wheels. The battery detaches and slides onto the charger.
I got it, a battery and the charger for $65 on closeout at Lowe's a few years ago, because they were discontinuing this model. I've been really happy with it, battery life is good too. I kept in behind the rear seat in my CCLB, now it's going in the ccsb in the same location.