Pics?
Or just use a lipo hard-case pack from HobbyKing that's nearer the voltage required - no exploding caps, etc.If your going to the effort why not replace with a lipo pack and external charger? it will perform much better. I have done this with many tools using a 25v/6S 5Ah lipo's. This is about double voltage of most of my tools, good chance any capacitors inside will explode and might burn out speed control, however motors will work fine - dont do this with any kind of grinder. Works very well for 12v compressors.
Worth doing a conditioning charge on all the individual cells before installation - if any are flat, once they're in situ they might go reversed and defunct /useless from that point, if used flat in the battery assembly.
Bit of extra time, but saves re-doing them.
I did my other five batteries today and took some pics that might be helpful for some.
This was the drill - i have two of these and they are nice to use with good power (when the batteries work), but all five of my battery packs were dead.
13.2 volts needs 11 4/5 sub C batteries in these packs.
First thing was to remove the cells from the old battery packs
I then drew a plan of the cells from the top and bottom of the pack:
This tells you how the cells are all joined together in addition to having the old battery pack next to you as a template.
Then you need your new cells (i had a few batteries to do)
These are the ones with tabs that you can solder together
Pull off the tabs and start soldering the pairs together (my soldering improves as the job goes on - i know it looks rubbish, but it worked!)
Once the pairs are soldered together on the underside, turn them over and follow the diagram for the top
Remove the connector from the top cell of the old pack and solder it to the new cell - this will differ depending on the drill/battery pack
Last connection
The card cut-outs are from the old packs and isolate the base of that top cell from the one it sits on top of
Then screw the pack back together and charge the battery.
Each pack took me between 60-90 mins whilst watching the TV (probably closer to 90 mins if i am being honest).
The frustrating news is that the battery pack I re-celled on 16th Jan above sounded different to the four I did today - it didnt sound to be turning as fast. When I put the voltmeter on it is was reading around 9V so a lot lower than the 13.2 expected. I took it apart and four of the cells were reading 0V (well, 0.04V ish). They were cheap, but I hope they dont all go that way. I had some spare, so replaced the faulty ones - they could have been bad from the start as i didnt check them with the voltmeter when i did the first pack.
Nothing to it - just get a charger from Hobby King to charge individual cells. Even the Lidl C, D, AA charger will do it. Just gets them all at full charge before you assemble the pack.How would i do that? Do i need special equipment? I'm still learning and wrongly assumed they would be ok as they were new.