Nicad Battery Fix Repair Guide?

robertwhite

I have a 24V Dewalt I want to try this method on but there are 4 contacts on the battery.

How do I tell which ones to jump? (nothing is marked and all 4 contacts are silver)

maninthesea

When I tried higher watage irons it ruined the batteries internaly and I still did not get good wetting of the solder. tried twice to confirm it was not a fluke. I am guessing it was melting the dielectric which is sometimes a plastic sheet. Maybe it works on some batteries but for me I just ruined the batteries(no big loss as they were not working anyway) and still did not get good physical connection. I'm thinking someone should be working on a highly conductive superglue. Patent that and you can make some $

pimpbot

... to sand the terminals with medium or coarse sandpaper first. Solder doesn't like to stick to smooth surfaces as much as rough ones.

Also, try heating up the wire with a gob of solder, and then try to stick it to the battery terminal, just so that you minimize the heat transferred into the battery.

I also found that regular cells were easier to deal with than ones with tabs spot welded on. I built up a battery that failed on the second or third ride because the spot welded tabs shook loose. Tools don't see as much heavy vibration as mountain bike lights, so maybe this isn't as much of an issue when rebuilding your drill battery. I used regular cells, sanded the tabs, and soldered them together with stranded wire. 4 years later, I'm still using the same battery, and has nearly the capacity as new.

I went through hell trying to build a bicycle light battery until a bud told me this trick. Worked like a charm!

FreedomRydr

I know this is an old thread, but the question still exists for some, so we continue to search for the various methods. As a former Electrical Contractor/Elec. Engineer Tech./Electrical Inspector, I know enough to be dangerous. So I read all of the threads here and other forums, and the YSUUSY site, and did it my way anyhow, and thought I would post the results for any other 'daredevil' sparkies, willing to give it a whirl. I have no welders or golf carts available, so I stuck with what I have, the handy-dandy automotive battery charger/starter. Working with a 9.6v Makita Ni-Cd, that would not charge past 6.4 volts.(I have had this drill for over 20 years, with the same battery!) I first shorted the terminals to blow out the crystals. A couple of quick shorts would do the trick. Taking the alligator clips of the charger, they clamp to the battery perfectly, to hit the negative and positive terminals with no need for soldered pigtails. I took a reading at the battery, it was 6.4v. The output of the 12v charger is 11.6v @10amps on charge, and 14.7v @50amps on start. standing in a safe location away from the battery, I plugged in the charger, set on 50A (Start). I left it for 30 seconds. I went back and took another battery reading and it was 7.8v. So I hit it again, this time leaving it for 5 minutes (battery and charger were outside of the house in an open carport). I hid in the house! Hearing no explosion after 5 minutes, I went out and unplugged it and took another reading. It was at 11.5v. This seemed suitable to me for a 9.6v battery, so I put it back in the drill and it works like a dream! No $20-30 replacement battery! I am now waiting until I run it down, to see if its native charger will bring it back, or if I will have to 'jump start' it every time! I will post the results and time passage. Thanks for listening!