Originally Posted by
rhammer
I own a weller 40 watt. Either that or the 80 watt version. You have to be careful though with the higher wattage that you don't get the cells too hot. It is easy to damage them by over heating.
This is why to use the 80w fattie. If you prep all your cells at once (I sand the ends with 220 grit and pre-tin), then dip the ends of the battery bars in flux, the soldering operation time total for each bar should be around 1.5 - 2 seconds per joint, max.
As with all soldering operations, a clean tip goes a long way. Keep a moist sponge near by to wipe it off between operations. The weller tips nickel coating is not that thick, but with a little care their life can be extended. I had one last 4 months before it started to get pitted. By contrast, I've had the tip on my Hakko for 2.5 years and it's as good as new. It may be more expensive, but you do get what you pay for...