NiCd battery repairs

[Collinian]

While looking for sub C batteries to repair my Rigid drill I ran across an ad for 'resurrecting' old units. Being naturally skeptical, I was wondering if anyone has had good results with this repair?

 

[giavra]

While looking for sub C batteries to repair my Rigid drill I ran across an ad for 'resurrecting' old units. Being naturally skeptical, I was wondering if anyone has had good results with this repair?

Depends from the method that you choose,some in the net try that via high current that a welder have others ways sold via ebay as instruction to this.There is no SAFE way for this but only to rebuild the pack with new batteries.

 

[softailgarage]

Seems to me I read something on this months ago. Seemed potentially hazardous and a colossal waste of time.
Welcome to The Garage

 

[uart]

While looking for sub C batteries to repair my Rigid drill I ran across an ad for 'resurrecting' old units. Being naturally skeptical, I was wondering if anyone has had good results with this repair?

As Giavra says it depends on the method that you choose, and since you don't link to the ad we can only guess.

- If they're talking about "zapping" the cells then it's a very short term "fix" in my experience.

- If they're talking disassembling the pack and thoroughly testing, re-balancing and replacing any faulty cells, then that would certainly revive a pack but it's probably more effort than it's worth.

- The best way to revive a pack is to rebuild it with new cells.

 

[Danglerb]

Mixed reports, I might try it since I have no sense and lots of curiosity, but nothing to rely on.

 

[signcrafter]

Just rebuild it with new cells, cheap and easy to do.

 

[big.jim]

put in freezer for an hour ,take out, stand banging on hard surface for a minute then put on charger , it does work i was sceptical but has revived a pack that was showing faulty on charger and wouldnt take a charge

 

[uart]

put in freezer for an hour ,take out, stand banging on hard surface for a minute then put on charger , it does work i was sceptical but has revived a pack that was showing faulty on charger and wouldnt take a charge

That's an interesting one Jim.

I've never heard of "banging" fixing a dead cell, so I wonder if it might have been a stuck thermal-switch that was causing the "don't want to charge" issue in your case.

Many packs have a thermal switch in them which is closed when cool but open circuits if the pack gets too hot. I've not come across these sticking in relation to power tool packs, but I've definitely seen them get stuck in other applications. So it could happen. I can easily see how freezing and bang might help in that situation.

 

[big.jim]

no thermal switches in my packs , dont know how it works but it does

 

[stitan06]

Where do u find new cells for batteries I wanna try some of mine

Sent from my GT-P5113 using Tapatalk

 

[uart]

Where do u find new cells for batteries I wanna try some of mine

For the couple of packs I've rebuilt I've just gone with the cheapest subc cells I could find on ebay. It's just not economical to rebuild a pack if you have to pay too much for the cells and ebaying from Hong Kong was the only way I could get cells under $2 each.

 

[uart]

no thermal switches in my packs

Have you actually disassembled one (completely) to know this for sure?

Unless your tools are very old and only have slow (>3 hr) chargers then it's very likely that they do have a thermistor buried in there somewhere. Typically the thermistor is connected between the main negative terminal and the third auxiliary terminal.

The attachment is one of my 24V packs partially disassembled. It shows the two wires leading to the thermistor, which is tucked down in between cells where you wouldn't see it unless the pack is fully disassembled.