Reviving Old Battery Packs?

[BDFan1981]

Have any of you ever tried reviving your old battery packs to make them have 1000 charges (like from day one)?

I'm talking about those old NiCd battery packs such as Black & Decker's "Univolt" series (1988-95). I would not recommend using any cordless drill battery packs from the 1980s and 1990s without recharging them via special devices to bring back the 1000-charge capacity.

Thus, what do you do to revive these battery packs on your old "Made in U.S.A." or "Made in Japan" cordless drills?

~Ben

 

[sberry]

I don't bother.

 

[Packard V8]

Been covered here a dozen times. Try a search.

 

[Outlawmws]

I don't bother.

Then Why bother wasting band width?


For Nicad ONLY (don't even try it with the new Li-ion and other technologies)

you can use a voltage source 2-3X the rating of the battery/pack, and on a COMPLETELY DISCHARGED BATTERY, hit it 2-3 times, to break down the internal plate shorts. It works a good percentage of the time. However, it will NOT make it like new, but if it works, you should get a bit more life from the battery.

 

[giavra]

just make some cycles of charge and discharge of the pack but only via using that pack (don't try to discharge with other ways). Keep in mind that Nicd batteries pack can have a 30 year of life at storage.

 

[Danglerb]

Nicd packs have crystals that grow through the insulation layers shorting them internally. Zapping them is supposed to **** the crystals. Sometimes it works, but its far from like new, and may not last much longer.

Something else goes on with "memory" where a battery slowly loses its capacity, and doing a few cycles of fully drain and charge can "refresh" the cell. I do this with a refresh mode on my charger prior to recycling a suspected bad cell. My charger will do how ever many refresh cycles you set, and shows mahr's of capacity when done. Matching capacity is good for multicell devices.

Unless I had some pressing need to get a LITTLE more use of a pack, I would not bother zapping. Nicds have improved, have it rebuilt with modern cells or replace.

 

[sberry]

Whats a waste of band width is encouraging something that isn't worth doing.

 

[Outlawmws]

Not worth doing to whom? You? You are one person. Google it; lots on the subject and I've done it myself. You are entitled to your opinion, but state it as an opinion, not as a god-given fact, since the empirical evidence points the other way. You wasted band with making a negative answer to a question that was not asked... I gave him an answer on topic and directly responding to the question.

 

[Jason280]

I've given up on old battery packs, its not worth the effort to me...

 

[uart]

Have any of you ever tried reviving your old battery packs to make them have 1000 charges (like from day one)?

You wont revive an old battery pack to have "1000 charges". Power tools are fairly hard on batteries, even many new packs wont ever make it 1000 charges.

The only real option to properly revive a battery pack in bad condition is to rebuild it with all new cells. Depending upon the availability, it may be just as cheap to buy new packs.

One money saving thing I have done on some of my old tools is to buy new cells to repack just one of its two failing nicad packs. I've then picked the best used cells removed from this rebuilt pack to "patch up" the second pack. This gets one pack back to "brand new" condition, and a second one in useable condition, so that at least you've got something to keep the tool running while the other pack is charging.

 

[CNGsaves]

Bring it into to the pro's . . . . . . . check your local:
. . . . .
. . . . . . . a) Interstate battery
. . . . . . . b) Allpak battery

They can rebuild or fix most anything.

 

[uart]

Another thing to mention re "zapping" batteries is that it does temporarily revive the voltage of a short circuit (zero voltage) cell, but it doesn't really fix the underlying problem.

I have experimented with "zapping" on literally dozens of cells, and I can report that in every case the underlying short circuit always returns, either after using the tool for just a few minutes or by leaving the pack unused for a day or so.

That's not to say that "zapping" is completely without merit. Even a temporary recovery of the pack's voltage can be useful in allowing the charger to correctly determine the state of charge, so the charger may play a lot nicer with a zapped pack than prior to zapping. Ultimately though, the zapped cell will generally contribute very little in the way of power to the overall pack when operating the tool.

 

[BDFan1981]

What did you think of the B&D "Univolt" battery packs (and the XR versions used on that group of tools) back in the day (1989-95)? How did they stand up to such abuse in commercial work?

~Ben

 

[uart]

What did you think of the B&D "Univolt" battery packs (and the XR versions used on that group of tools) back in the day (1989-95)? How did they stand up to such abuse in commercial work?

~Ben

How have yours held up Ben? I mean, what is the current condition of the packs you're trying to revive?

There is a fairly big variation in what constitutes a spent battery pack. Early signs are usually a pack that will function ok if used straight away, but will lose it's charge relatively quickly (over a couple of days) if left to sit. Later the pack may not function well even if used straight away, or may even refuse to charge.

Also, are these old tools that you've owned since new (and perhaps left sitting for a long time), or is this some old stuff you've recently acquired (perhaps with the idea of restoring)?

 

[Bigplum]

Works for me , I use a old school 4 amp 12v battery charger, dismantle or loosen the pack to find which cell is bad ( sometimes more than one ) I use a DVM to check
I then flash the cell with 12 v reverse polarity , just a couple of quick swipes then repeat with correct polarity , always wearing safety kit , you'll know if its worked by checking for 1.2 volts on the battery ,
Generally gets them going again , works on NImH batteries too , just be careful and wear heavy gloves and faceshield , work at arms length not over it, never had one blow but you never know .
Don't try it on lithium , they will go BANG big time

 

[Outlawmws]

Uart, What is your zapping process? I've had relevantly good luck getting then back working to a reasonable if not optimal state.

I do agree that if they do go south a second time, the process is less effective if tried again, but my initial zaps are above 80% success getting them working...

 

[BDFan1981]

The problem is, I don't have any Univolt or XR cordless drill.

The only cordless drill I have is a low-buck model 9045 (CD1000) 4.8-volt, 2-speed control (225 or 450 RPM) depending on how far the trigger is pulled. The batteries are self-contained. This being a 1992 model, it probably isn't workable now and I'm dying to get rid of it (hopefully without sending it to a landfill).

~Ben

 

[uart]

Uart, What is your zapping process?

I've used various methods, you need a higher voltage than that of the pack but it's really the current that's important. I've done it on NiCd and NiMH "AA" and "AAA" cells and even those small 9V rectangular batteries, as well as on my power tools. For the small batteries I often just use a plug pack (wall wart), typically it needs about 2 amps to zap a "AA" and only about 0.25 amps to zap the little 9V's.

With my power tool packs I have zapped them from another higher voltage pack, but generally I like to use my little AC stick welder. I know it sounds brutal, but at least it's actually is current limited. I wind it all the way down to the lowest current setting (about 35 to 40 amps) and put a big 10 amp diode in place of the stick. This makes it half wave rectified and only half the average current, which seems to be a good amount for a few short zaps.

 

[djjsr]

For me it's not worth the risk.

I'm concerned that a battery that I've screwed around with might overheat or explode or catch fire while in the charger when I'm not around.

If I found a "reviving" method that was approved by a battery manufacturer or expert, I would try it. But a "try this" method developed by some do-it-yourselfer doesn't cut it for me.

jmo

 

[sberry]

Like most others with extensive experience I found that trying to save some worn out junk isn't worth it. Not only the "second time" but the first as evidenced by the need for a second.