I'm going to have to disagree with you rc-zombies. 480deg.C=896 Deg F which is just fine for soldering cells. The hotter the iron and higher wattage and greater thermal mass allows you to melt the solder more quickly, so the iron is on the cell less time, allowing less heat to penetrate deep into the cell. Most cell damage from soldering occurs when you use an iron that's not up to spec and you sit there and hold the iron on for a long time trying to get the solder to melt.