1/2 impact gun ?

[Westheath]

it will be for DIY use although I do quite a lot and a few side jobs for beer money

If it’s light use and not every day then something cheaper than Milwaukee will do, take the claimed specifications with a pinch of salt as side by side the performance is obvious comparing a B&Q budget tool v Pro tools and the price reflects this.
I have a £1000.00 worth of batteries for my 1/2 Millie but then I’m using it everyday workshop and mobile, it slaughters higher rated guns I’ve tested the build quality is outstanding after 8 years of use.
I’m sure the crank bolt job you got stuck on has a proper locking tool for it

 

[Frontstep]

Theres a popular mechanics test to read,

https://www.popularmechanics.com/home/tools/reviews/g2028/the-best-impact-wrenches/

 

[bembo449]

well I ended up borrowing a 110v 3/4 hitachi gun , did the job easy as , shame the bottom pulley wont come off now ive got the bolt out