trichbits 12v 35a soldering iron.
 

I have one of these, had it for years. The only thing was, It came with a 9mm tip witch was fine for doing old battery cell's. Any way I have found a firm that do replacement tip's that fit strait on all size's.
www.antex.co.uk.
Just thought I would shear this with you as there must be a lot of people out there with these irons