Hi,
I found a few boxes of sealed Philips C and D cell NiCads in the attic. I can’t see a date but I know they are approx 20-25 yrs old.
Visually they look fine, no leakage.
Do NiCads go bad and become dangerous over time? (dendrites etc)
I think NiCads have really bad self discharge, right? Those are probably dead. But I don’t think there would be any harm in testing voltage just for the fun of it. Someone else will have to advise whether it’s okay to try to charge them. If they were mine, I might try a slow, gentle charge to see if I can get some life into them. Just cuz I don’t know any better. :smiling_imp:
I’ve a handful of NiCd AA’s which must be about 10 years old, cycled them a few times and they are recovered to about 75% of claimed capacity.
That said, claimed capacity is very low and self-discharge is high compared to modern NiMh.
FYI, NiCd cells have been phased out throughout the EU because of the toxic cadmium leaching out of landfill.
May be shot at that old and kept in an attic (hot), but NiCads can be stored at zero volts, so they might be OK. I’ve never had a NiCad leak. That should not be a problem. I’ve never heard of them becoming dangerous.
You probably need a dumb charger to boost them, or charge at 1/10 capacity for 15 hours. Cycle them 5-6x and see what you get. If you have a smart charger it may not be too happy with them, at least for the first initial cycles. Depends on how bad they are.
I’ve got some very old 1200mA D-cells that still hold a pretty good charge. They must be 20 years old. When I got them they were new (found in a drawer) and had been completely dead for an indeterminate time, probably years.
I will try one on my Li-500 at 300mA and see what happens. The back of box says 50mA charging current but 300mA is the lowest I can do with the Li-500.
The big ones don’t fit in the Li so i’ll recycle them.
4000mA is WAY newer than my old ones, if they are indeed that capacity. 300mA is not a problem, assuming the Lii-500 will deal with them. I think it rejects dead cells. If you don’t have a dumb charger suitable to get them going you can ‘jump start’ them with another decent charged cell, even a AA; + to +, - to -. If that won’t do it use a 18650……VERY BRIEFLY!
50mA would be the standard dumb charger slow charge for 15 hours.
I had/have plenty of ancient NiCd cells that grew green “mold” across the (+) end. Dremel with the brushy-thing cleans it nicely, ’though sometimes whirrs away the heatshrink if you linger too long.
Try charging it, see if it holds a charge. If it starts at 0V, chances are it’s got internal whiskers shorting it. Charge up a big capacitor and zap it a few times. Pound it good, enough to spot-weld the wire to the tab. 
Should “blow the fuses” of those whiskers.
Then, once it reliably holds a partial charge, charge it up sloooowly, like C/20 to even C/50. Let it go. They can trickle-charge forever at lowlowlow currents without too much damage.
Cycle each cell a few times, see if it, well, works. Then, you’ve resurrected them successfully if so. If they stay bricked, or start to charge but keep discharging at those low charging currents, toss ’em.
Æons ago, I grabbed a bunch of power-drills with 12V NiCd cells for about the price of just what the sub-C cells would be worth. Left most of the cells in-place, only would scrounge what I needed (and got kewl motors/gears from the drill if I needed any). Probably still got a bunch of those drills/cells somewhere.
So… they don’t leak, do grow “mold” around the seal, do grow internal “whiskers” that can short ’em out, stink like vinegar if you overcharge ’em enough to vent, but they can otherwise take a pounding and not complain much if at all. You really gotta kill ’em good to kill ’em dead. Eg, reverse-charge them, do other nasty nasty things to them.
I learned something here today. Thanks!
varbos, no LiitoKala Lii-100 or equivalent clone around? Cheap as chips, handy and for sure will handle those goliaths as they seem to be large button tops.
Don't worry with charge rate, 1A is fine for those cells.
Cheers :-)
As far as zapping a cell with a big cap, I had a dinky multi-voltage adapter (ie, multi-tap transformer, cheap diode+cap to filter it) that would float to 18V or so on its “12V” setting. Stacked 25V-35V caps, starting from, say, 4700µF and up, just keep daisychaining ’em together. The charger was probably a whopping 300mA.
You can start small to see if you can pop the whiskers gently, but I’d always pound it good. Got computer-grade 30,000µF caps that I even used as stiffening-caps for my car’s amp. Big honkin’ screw-terminals on top, throw some 16ga wires on them and just keep parallelling ’em.
That dinky little charger would take forever to build up a charge on that beast, but when it did, you could easily spot-weld together whatever you’d hit with it.
I probably still got a few sub-Cs with pockmarks on the tabs from doing just that.
If you wanna really go crazy, hit it with a charged-up photoflash unit.
Here ya go…
’Though you can probably hit the surplus market and get ’em cheaper.
No kid should be without one.
I have a Li-200 and Li-500; the D cells don’t fit either. The diameter means the button top can’t touch the terminal properly. A pity because I found about 6 packs.
(Edit - I am mistaken. If I squeeze it down with some elastic band it is charging now)
I tried a couple C cells and they seem AOK, charged up without any problems or overheating. I am doing a capacity test now. I am very surprised because I am not mistaken about the age…I got these in the 90s and they have been in the attic ever since. I guess Nicads last a long time !
Wow! I sorta knew NiCads were tough, but I never knew they were THAT tough! 
:+1:
The first tested C cell got 900mAh on first test. Rated capacity 1200mAh :+1:
Yeah, NiCD’s are tough and last a long time. Only problem is losing their charge so fast whether using them or just sitting around.
I had 4 C cell NiMH’s in an old radio for well over 30 years. They were charged hundreds of times. They finally fell under 50% capacity and I discarded them.
NiCd still have a purpose IMO. I just rebuilt a couple Milwaukee 18V packs I scrounged from the recycle bin. I use them in my 1/2in impact because they got more Sack than the NiMh or even the Red Lithium packs. I gave up on trying to swap out or replacing with “good” used single cells in them as it never seems to end. Sucks to have to charge them after sitting for a week or more but some of the old chargers will continually charge them if left in the charger. But those same chargers will Kill a NiMh pack if left in the charger.
those 4000 mah d may surprise you.
made in france=saft.
solid plate good for high rate.nice super hotwire fuel.
charge em up on a slow dumb charger and try em out.
the c have a sub c inside.still useful but for a less demanding things like a radio.
btw my mom still has a ge am/fm portable with 4 3200mah ge d cells from 1971!
i modded it to charge from a wallwart when i was 10.it was the official camping radio.
she charged it up on the announcement we would have high winds from ike.
she played it the whole 3 weeks it took to get power back.
she plugs it in overnight every other month to keep it ready.
these were surplus and used when i got them at mendelsons.
so yes good nicads can last decades.
charging yours slow will tell you if they have dendrites.
if they come up run a few cycles to wake them up.
Nickel Cadmium (NiCd) batteries were the typical technology for many years, but they became out of date at present. NiCd is applied where high discharge level, long life and economical price are relevant. As NiCd includes toxic metals such as cadmium it’s environmentally unfriendly and must be recycled or disposed of in the proper way.
They are heavy and have “memory effect”. When you recharge a NiCd battery that hasn’t been totally discharged, it “memorizes” the previous charge level and thus the maximum capacity becomes equal to this level. The “memory effect” is determined by crystallization of the battery’s substances and can decrease your battery’s life span, even make it useless. In order to avoid it, you should fully discharge the battery and fully recharge it again at least once in a few weeks.
Advantages:
Fast and easy charge — even after long-time storing.
Large number of charge / discharge cycles — if thoroughly maintained, the NiCd guarantees over 1.000 charge / discharge cycles.
Excellent load performance — the NiCd permits recharging at low temperatures.
Long shelf life – in any condition of charge.
The lowest cost.
Available in various types and sizes.
Limitations:
Comparatively low energy density.
“Memory effect”.
Environmentally unfriendly.
Comparatively high self-discharge — requires recharging after storage. {Info from Armytech website }
wonder what the ir is now?
if solid/sintered plate probably very low.
seems foam/pasted plate cells rise a lot with age.