This is what i was looking for:

http://www.offshoreelectrics.com/how...tery_packs.htm

WHAT was I worried about. Dad pitched up at 10am with a huge thirty year old mains soldering iron, which got proper hot, very quickly.

An hour and three quarters later three packs were ready for waking up on my charger. The solder joints were made in no time and the bodies of the cells didn't heat up at all.

A combination of scouring the terminals, using a big tipped (15mm wide) hot soldering iron and an Orion jig made the job a lot easier.

Thankyou again for your advice.

Elliott.

Hey, Ive bought some cells but they wont be here for at least 2 weeks. I want to be as kind as possible and heat the cell as little. Would a decent technique be to tin the battery bar ends, then add flux to the cell top , melt the solder on the bar and then put on bar so less heat transfers to the cell?

As for flux, where can I buy some, maplins do it only in a pen and its nearly a fiver!

Yes I saw that but that way your directly soldering over the cells vents. The way I was saying, your not directly heating the cell.

O, yeah i do it how u said, ass solder to the bar as well. Worked perfect on my packs.