Welder saves nicad batteries!

[puddytat]

Hi Rick, thanks for all your time on this very costly when they don't work properly battery subject.

Although the thread is now 7 months without a post, I read all posts and have a few battery packs that from day one were poor performers so there's light at the end of the tunnel I hope.

I hope that the fact that there have been no posts for the last 7 months would not be interpreted in that everyone who was posting has blown themselves up....LOL.....only yoking.....cluck cluck.

I was surprised at someone doing this with a 12 volt battery....probably the difference in sulphating up from not charging as opposed to old age and loss of plate material etc.

BTW, you can buy over the counter sub C type NiCad cells with tags already on them from your local electronics shop........ well our local Jaycar electronics store in Australia has them....costs about $8 per cell......soldering would be easy as the tags are already attached to the cells.

I think I'm going to have joy with this method with a number of drills and yard blowers that had battery packs fail in a year......I've also got s bundle of AA cells that have died over the years and just got boxed to be recycled.

I've noticed that even when buying new NiMh batteries, after even a short while you often get premature stoppages when one cell goes down and the camera etc powers down.
Ian.

[Rick V]

Hey puddytat, how ya been keeping?
Yeah all the previous posters "has blown themselves up."

RE: I was surprised at someone doing this with a 12 volt battery.
Yeah, this does not work for 12 volt car/truck lead-acid batteries... although I have used my welder recently to charge a deep cycle battery at 90 amps! (Not recommended.)

Good luck to you with your attempts to flash-recover your Ni-Cd batteries.
As I said, if it's already dead, you have nothing to lose and a fair chance of winning.

[Bob_C]

Just for the record we haven't ALL blown ourselvs up, at least not yet.

And I'm still using the batteries I zaped last March.

[Rick V]

Just for the record we haven't ALL blown ourselvs up, at least not yet. And I'm still using the batteries I zaped last March.

Ah-ha, OK then... just 1 survivor! Glad to hear it worked for you Bob_C !

[Renagade]

Make that two
ps batteries still work

[ItsMillerTime]

Three and we finally sold the car so I can't say if the battery is still working or not..

[Rick V]

OK, see that... ONLY 3 SURVIVORS!

[JohnR]

This is nothing new. He'll they make machines that do this exact thing, except computerized. They use up to 300a. It was very popular in the r/c crowd at the pro level.

Sent from my Galaxy Nexus using Tapatalk 2

[Rick V]

I had an amazing success yesterday.
Went to a Salvation Army Thrift Store and bought a 7.2 volt battery powered drill for just $5 - figured even if the battery was dead I could use the motor & clutch.

Got home and checked out the battery... weird!
Instead of having a high resistance and hardly taking a charge, the whole battery appeared shorted - only having a voltage drop of 0.3 volts with one amp flowing through it. What??? I'd never seeen that before.
I opened up the battery case and checked each cell individually - each one was shorted. ?? Weird! ??

Later it hit me! Maybe all the cells have those nasty dendrites shorting them internally.
I hooked up a 40 amp battery charger and gave the battery a few hits at 30 amps.
I checked the battery again - Back to life! After one charge/discharge cycle, it's like brand new.

This is a great technique for Ni-Cd batteries.

[Stix]

Has anybody tried using car batteries instead of a welder to zap the NiCad batteries? My welder is AC, but I've got a bunch of 18v NiCads that are dead. I'm thinking I could hook two car batteries up in series, so that would be 1.3x the 18 volt batteries. Any idea if that's enough voltage? If not, I guess three car batteries might work.

[Rick V]

Hey Stix, since nobody with actual experience answered you, I'll try.
Likely yes, two 12volt batteries (24-26) volts should drive enough amps through your 18volt NiCads - especially because they are dead (voltage way below 18volts). Remember, just pop them a time of two or three or four. You just want brief inrushes of high current to burn off those thin dendrites shorting out the NiCd cells. Good Luck!

[59halfstep]

Hey Stix, since nobody with actual experience answered you, I'll try.
Likely yes, two 12volt batteries (24-26) volts should drive enough amps through your 18volt NiCads - especially because they are dead (voltage way below 18volts). Remember, just pop them a time of two or three or four. You just want brief inrushes of high current to burn off those thin dendrites shorting out the NiCd cells. Good Luck!

Hey Rick - I have had this thread on my mind for the last month or so. How about an after action report on this. Enough time has passed since you introduced this to the group, that you should have some data for us. Do the batteries hold or do the revert back to the way they were.
Thanks

[Rick V]

Hey Rick - I have had this thread on my mind for the last month or so. How about an after action report on this. Enough time has passed since you introduced this to the group, that you should have some data for us. Do the batteries hold or do the revert back to the way they were.
Thanks

GREAT QUESTION!
HA - That Depends.
My case is not typical. I had three pretty crappy 14.4 batteries for my chaepo-crappy "JobMate" drill. The batteries used low quality 1.2 amp-hr cells with a high self-discharge rate that gave the battery a limited shelf life.

Yes, the big pulse of current restored the batteries to working way better - delivering their rated power but the self-discharge rate was still a problem for me. e.g. I'd go to use a battery after 6 weeks and there was not much left; yet they charged just fine to full power.
So the high-amp pulse worked... the batteries worked just fine.

However, hating the short shelf life of my crappy cells, I swamped out the twelve 1.25 amp-hr sub-C cells for twelve 2.5 amp-hr AA batteries. The drill lost a lot of torque using the AA cells (Enegizers) but I have way longer shelf life now - which was more important for me.

If you have good quality batteries from say Milwaukee, Makita, Ryobi, DeWalt, Ridgit, etc. their self life should be good and you won't have my problem. I'm sure that the small effort to restore them will be well worth it and last for months. OK, so you might have to hit them again in four months but really you should be good to go.

Other folks may have had different experience and perhaps they will chime in.

[59halfstep]

Thanks Rick - this is a great thread. I too am hoping others will fill in with their experiences.
Have a good holiday.

[Bob_C]

59halfstep,

The batteries I zapped were really DEAD, they were sitting i=on the shelf for over 2 years. When I read Ricks post I felt I had nothing to lose so I zapped them.

Now about 18 months later I'm still using them, do they hold a charge like new, no, but I can get a days work out of them. As soon as it cools down so I can get into the garage, (90 in the shade today), I'm going to zap them again. It's a he!! of a lot cheaper than new ones at Lowe's, $89.?? as of last Monday.

In answer to your question will they revert back yes they will, but that's what batteries do... they die of old age. This just gives them a shot of Geritol. If your old enough to remember what that is :-).

Luck

Bob

[59halfstep]

[QUOTE=Bob_C;2831891]59halfstep,
This just gives them a shot of Geritol. If your old enough to remember what that is :-).

I do remember what that is and I am ready to give myself a shot.

Thanks for the after report.

[Stix]

Hey Stix, since nobody with actual experience answered you, I'll try.
Likely yes, two 12volt batteries (24-26) volts should drive enough amps through your 18volt NiCads - especially because they are dead (voltage way below 18volts). Remember, just pop them a time of two or three or four. You just want brief inrushes of high current to burn off those thin dendrites shorting out the NiCd cells. Good Luck!

Hey Rick - thanks for the reply. I hadn't thought about the voltage difference compared to the dead NiCads. I can't wait to try this -- any life at all out of my dead batteries will be worth it!

[FORTEALLOY]

This was a great tip, thanks for all the tips & clarifications.

A friend gave me an older B-D 18V cordless drill with 2 slide packs. It worked, but my 12V Dewalt would run circles around it. "Popped" each of the packs a few times, then charged overnight. Been driving 4" deck screws all week, my arm gets tired before the battery runs down.

This is what worked for me.....
XMT 350, settings: 95amps, VA ("dig") set to zero, OCV showed 70V, confirmed with testmeter. Both packs were run down (16-17v), not totally discharged. Both showed 20v after several taps. Wear a face shield, its going to spark.

Will see how they do long-term, but this week has been amazing.

[Softwireman78]

My Uncle just did two 12v DeWalts a few hours ago and sent me a video. It does seem to work at rejuvenating the batteries! Someone in Big D had a 12v DeWalt (727) drill, two batteries, and charger posted for $20. Made contact with the seller and offered him his asking price plus an additional $20 to ship em to him. The guy replied and said if he'd send a prepaid postage box he'd give them to him!

[VPT]

So yesterday I was trying to use my cordless drill again. The batteries sit on the charger for a few minutes and show full charge but then only work on the drill for a few minutes and start to cut out.

I remembered this thread but was unsure which batteries the welder trick worked on so I wanted to check before I did anything.

The ones I have are the porter cable 18v lithium batteries which i guess don't take kindly to this welder trick. Is there anything else that works for the lithium batteries?

This is the third cordless junk I have owned in the last 10 years. My next drill is going to have a cord!

[Softwireman78]

Seems I've read li-ion will explode. Don't hold me to it though. Ni-cad I know for sure it works and POSSIBLY even ni-mh. I'll see what I can find in a Google search cause I'd like to know also.

[Softwireman78]

Source: instructables.com

Li Ion batteries don't have the kind of memory effect that NiCd batteries have, so they can't be reconditioned.

Some Li Ion battery packs (e.g. laptop batteries) have a little circuit that keeps track of the capacity of the battery. Occasionally, this sensor can get thrown off-track by repeated shallow discharge and recharge cycles. If so, you can recalibrate the sensor by letting the battery discharge fully (to the discharge cut off - put that screw driver down!!). This doesn't actually do anything beneficial for the battery itself, it just resets the little monitoring circuit.

Same source info accredited to wiki:

A stand-alone Li-ion cell must never be discharged below a certain voltage to avoid irreversible damage. Therefore all Li-ion battery systems are equipped with a circuit that shuts down the system when the battery is discharged below the predefined threshold. ... This is also one of the reasons Li-ion cells are rarely sold as such to consumers, but only as finished batteries designed to fit a particular system. ... Short-circuiting a Li-ion battery can cause it to ignite or explode, and as such, any attempt to open or modify a Li-ion battery's casing or circuitry is dangerous. Li-ion batteries contain safety devices that protect the cells inside from abuse, and, if damaged, can cause the battery to ignite or explode.

[Rick V]

... The ones I have are the porter cable 18v lithium batteries which i guess don't take kindly to this welder trick. Is there anything else that works for the lithium batteries?

No, lithium batteries are super sensitive to over voltage.
Typical lithium cells used in a cordless drill or a laptop computer are 3.6 volts at about 2.4 amp-hour. Maximum charge voltage is 4.2 volts per cell (4.0 volts to be safe).

In an 18 volt cordless drill the manufacturer may use 5 cells for 18V @ 2.4 amp-hour or might use 10 cells (2 parallel sets of 5 in series) for 18v @ 4.8 amp-hour.

In a 10.8 volt laptop, 3 cells are used in series to get 10.8 volts. 2 parallel sets of 3 in series is standard for the typical 6 cell 10.8v @ 4.8 amp-hour laptop battery. A high capacity battery uses 12 cells to provide 10.8 v @ 9.6 amp-hour.

I had a 6-cell laptop battery die and replaced it. Took the old one apart and damaged one cell doing that - leaked a hydrocarbon liquid. Anyway, there was 1 cell that was the problem. So, I had 4 good cells - Yippe! Until, I charged them without looking on Wikipedia!!
I charged them at 4.5 volts per cell and might have got away with that until I raised the voltage to 5 volts per cell => result was 2 open circuit cells and the other 2 cells went down-the-tubs in amp capacity. All wrecked by me.
YOU CAN'T FLASH LI-ION BATTERIES.

[VPT]

Another 2 drills for the scrap pile. If I want portable I'll carry my eu2000 around with me.


Next project is pulling chucks off of perfectly good porter cable cordless drills.

[Rick V]

Hi VPT,

RE: Next project is pulling chucks off of perfectly good porter cable cordless drills.

You might want to look around on say eBay for replacement batteries... oops, they are expensive - close to $70 minimum... and that's for 18v @ 1.6 amp-hour.

On the other hand, if you are the MacGyver type, you could just buy the cell paks - as shown.

Good Luck!