I am looking at Makita tools and want to buy an impact driver. In looking at the specs I see that I can get the same torque etc. between a 10.9 volt and 18 volt. Can anyone explain to me what is the difference. Will the 10.9 do the job? I do my own house reno's and I need something light weight that will take stress off my wrists.

Hi,
Generally it is in the motor construction internally. Check to see if it tells you run times, charge times and weight, and choose that way other things being equal.
Peace,
Clarke