Craftsman C3 Battery Repair, Part 2

Описание: Once the defective cells have been identified and removed, it's time to solder in some new cells to replace the bad ones.

I tinned the inside face of the original battery tabs with my soldering iron. For the lithium cells themselves, I found I needed to apply some solder flux to the end terminals to get them to accept solder. I also found if I turned up the heat on my Hako-936 soldering station to the 400-450*C range, that helped to overcome the thermal mass of the cell to allow me to tin the surface a bit.

Then insert the cell into the pack, making sure to get the cell polarity correct. Each bridging tab will have the positive terminal from the one cell and the negative terminal from the next cell. So make sure to have the opposite terminals coming together.

Then I held the soldering iron down onto the tab, watching for it to just flow onto the battery terminal. Then use a metal object to apply downward pressure on the tab and remove the soldering iron. You need to hold about 5-10 seconds until the solder solidifies or you'll get a weak solder joint.

Repeat the above process for each terminal and make sure that each cell is firmly pressed into the battery pack so it will fit inside the case when you finish.

Pack voltage tested out fine, 20.6 volts after I have individually charged each cell to 4.1v. I found I did break one of the fuel gauge wires, so I'll fix that in the next video and then time to test the pack in a power tool.

With Youtube removing all the annotations from older videos, all this information was lost from the video. Troubleshooting to find out which cells were bad started here:
   • C3 Battery Troubleshooting, Part 1  
   • C3 Battery Troubleshooting, Part 2  
   • C3 Battery Troubleshooting, Part 3  

For the replacement cells, took the mfg. and part number information off the old cells, searched for that on eBay and ordered some replacements. I was able to match all but the capacity, the old cells were 1300mAH, new cells were 2000mAH, but otherwise the same parameters as far as C rating, internal resistance, etc.

Thanks for watching.