Valdyr

I have my own question about making a coilgun, but didn't want to make a new thread needlessly. I am considering making a coilgun, and was wondering if it would be possible to use the inverter from the screen of an old laptop to convert the DC voltage from a bettery to AC so it can be stepped up using a transformer (The inverter already has one, so I might just use a transformer as a rectifier (Same number of coils on both sides) to change it back to DC for charging the capacitors), Also what sort of voltage am I likley to get from it?