Dead Ni-Cad Cordless Drill Batteries, Revive Them

[CHELLIE]

My 18v coleman drill motor rechargable battery Quit Taking a Charge, they were Dead Dead I looked on EBay for some replacement Batteries, and the replacement Battery is more than what i bought the complete Drill assy. for on Sale Then I remembered about reading how some people Revive these battery packs, I did a Search on youtube and Google and found some information on how to do it, AT YOUR OWN RISK I used 2- 4900mah 5 cell lipos in series for about 40 volts, and touched the pos to pos and neg to neg, about 20 times just real quick, and put the battery back in the drill motor and it works now yea, i have to fully charge them up now, but i got my cordless drill back working, Take care and have fun, Chellie

Part2 - How to revive / rejuvenate / fix rechargeable NiCd battery for cord

[JZSlenker]

Please report back on this after you charge fully and test it. Thanks!

Any science behind why this might work?

[SHADY]

Any way to do it to over discharged lipos??

[CHELLIE]

Originally Posted by JZSlenker

Please report back on this after you charge fully and test it. Thanks!

Any science behind why this might work?

yes, there are crystals that build up in the battery and block the flow of Electrons, the higher voltage Zaps them away

[CHELLIE]

I dont know if i would use a welder or not to revive a dead Ni-cad but it works
this guy explains it more, Take Care, Chellie

Instructables TV Vol. 1

[CHELLIE]

More info on Google.com

http://www.google.com/#hl=en&sugexp=...2c329aebecaf30

[CHELLIE]

So Far so Good on my Revived drill batteries, one of them held a charge over night but was weak in the morning, and the other held a charge just fine overnight, they charge up good, and as long as i am able to use them by chargening them up before i use them, that good enough for me, at least they charge up now and hold a charge for a while Take care, Chellie

[groundrushesup]

Originally Posted by SHADY

Any way to do it to over discharged lipos??

I would highly recommend that you avoid trying this.

Shorting NiCads causes sparks and a warming or distention of the cell.

Shorting LiPO's causes a chemical fire.

[kyleservicetech]

Originally Posted by CHELLIE

My 18v coleman drill motor rechargable battery Quit Taking a Charge, they were Dead Dead I looked on EBay for some replacement Batteries, and the replacement Battery is more than what i bought the complete Drill assy. for on Sale Then I remembered about reading how some people Revive these battery packs, I did a Search on youtube and Google and found some information on how to do it, AT YOUR OWN RISK I used 2- 4900mah 5 cell lipos in series for about 40 volts, and touched the pos to pos and neg to neg, about 20 times just real quick, and put the battery back in the drill motor and it works now yea, i have to fully charge them up now, but i got my cordless drill back working, Take care and have fun, Chellie

Part2 - How to revive / rejuvenate / fix rechargeable NiCd battery for cord

Yup, did that more than once over my past (to many) years. What can happen, is if you allow those Nicads to go dead, they have a tendency to develop shorts internally. And, hitting them with a few dozen amps can vaporize those shorts, and the cell can be recharged. And, the story goes, if the cells are fully charged, and an internal short should arise, the battery itself vaporizes the internal short, and the owner of the drill is non the wiser.

Rumor had it back then that the cause of these shorts was due to poor quality separators between the positive and negative plates inside the battery.

But, the best solution is to replace the cells them selves. Most of them are of the "Sub C" type, universal in battery operated tools, at least before the Lithium systems took over.

I've got an Porter Cable battery operated power drill that is going on 10 years old. The batteries got to where their "Shelf Life" is only a few weeks. So, the cells were pulled out, and replaced with some Sub C cells that were last used with my Astroflight geared brushless 40 motor. Took awhile, but those batteries are no longer available.

[CHELLIE]

Originally Posted by groundrushesup

I would highly recommend that you avoid trying this.

Shorting NiCads causes sparks and a warming or distention of the cell.

Shorting LiPO's causes a chemical fire.

Yes there is some risk involved, that why i say, Do so at YOUR OWN RISK Dont Blow yourself up Wear Safety glasses and gloves, just incase if your going to try this, Be Safe, do it outside, Take care and Have fun, Chellie

[SHADY]

Originally Posted by groundrushesup

I would highly recommend that you avoid trying this.

Shorting NiCads causes sparks and a warming or distention of the cell.

Shorting LiPO's causes a chemical fire.

That's what I was thinking... But was hoping to find some way to maybe place a small trickle charge on it to gain enough voltage for a regular charge to take.

I found a really nice battery in the woods while looking for my T28, but it's too dead to take a charge from my Accucel 6...

[groundrushesup]

Originally Posted by SHADY

That's what I was thinking... But was hoping to find some way to maybe place a small trickle charge on it to gain enough voltage for a regular charge to take.

I found a really nice battery in the woods while looking for my T28, but it's too dead to take a charge from my Accucel 6...

Well to be honest, if you get a new battery that you accidentally drain past LVC (say it was stuck in a tree overnight) you CAN put it on the NiCad mode of your charger and monitor it until it comes back above ~9v (approx 3V per cell) - then you can attempt to charge it normally and see if it recovers.

The difference here is when I say you use the NiCad setting - slow and steady input voltage - not arc-welding the terminals lol


In my experience the lower the internal resistance of a LiPo the easier it is to revive from the dead - I have killed 2 transmitter LiPos by leaving my Tx on in the case - and because these batteries are usually around 3-5C discharge max, one or more of the cells is unrecoverable. That said, I have treed a few planes overnight with Thunder Power or Rhino cells and had no problem briging them back.

ITs worth a shot. Keep a watt meter handy, and even better is a cell tester that can show you individual cell voltages so you can see if one cell is way out of balance, or other conditions that may require some TLC.

GRU

[SHADY]

Originally Posted by groundrushesup

Well to be honest, if you get a new battery that you accidentally drain past LVC (say it was stuck in a tree overnight) you CAN put it on the NiCad mode of your charger and monitor it until it comes back above ~9v (approx 3V per cell) - then you can attempt to charge it normally and see if it recovers.

The difference here is when I say you use the NiCad setting - slow and steady input voltage - not arc-welding the terminals lol


In my experience the lower the internal resistance of a LiPo the easier it is to revive from the dead - I have killed 2 transmitter LiPos by leaving my Tx on in the case - and because these batteries are usually around 3-5C discharge max, one or more of the cells is unrecoverable. That said, I have treed a few planes overnight with Thunder Power or Rhino cells and had no problem briging them back.

ITs worth a shot. Keep a watt meter handy, and even better is a cell tester that can show you individual cell voltages so you can see if one cell is way out of balance, or other conditions that may require some TLC.

GRU

Thanks, I will give that a try. Using all the proper safety measures of coarse...

[JZSlenker]

Well since 18V Dewalts cost $80 to replace still I think I will try it.

[radialarm]

I used the welder method on my Makita 7.2V battery circa 1999 and it was a great improvement. It might need a few more zaps, but it's a lot better than it was before.

[solentlife]

NiCd's can be revived from 2 situations ....

The crystalite as exlained above by shocking it by quick zaps of high voltage - but usually shortens the life and capacity of battery significantly.

Second is the all too common reversed cell where a pack is left switched on and drains right down and where 1 cell actually goes negative. It's only a decimal of a volt and needs a good meter to see it - but it happened quite often. This time a small jolt is often good enough to correct it. But that cell will always have a tendency to fail after.

Above was told to me by one of the guys at a well known Co's battery factory near where I used to live in UK.

Of course NiCD's are no more retail - NoCD's ?? - so that's a historical matter now. And he told me NOT to do it with other types of battery - it only is applicable to NiCD's.

One of the best ways to resurrect a cordless apart from replacing the cells of course, is to convert it to corded of a 12v supply. To keep balance of the drill - you disconnect the cells inside the pack and lead your cord through it to the contacts ... using the pack as the contactor. Even a 18V drill will often run happily of a car plug ... but if you have a 12 or 14.4V drill - then that's spot on for this conversion. No need to waste a good drill !!

[CHELLIE]

Originally Posted by JZSlenker

Well since 18V Dewalts cost $80 to replace still I think I will try it.

It saved my batteries, they work now, I have to charge them up before i use them, but at least they are usable Take care, Chellie