question about NiCad Batteries... : LUSENET : TimeBomb 2000 (Y2000) : One Thread

I have a question,,,,,,Can you use solar battery rechargers to recharge ANY NiCad rechargable battery? A sales person told my mom that you have to have a Solar rechargable battery only for this, and that you had to use an electric recharger for most NiCads.....this didn't sound right to me.......I thought you could recharge any NiCad battery with solar energy.....

-- KLT (, July 22, 1999


Electricity is electricity and the battery doesn't care is it was generated by a solar panel or a utility company. The sales person doesn't know what he is talking about. The critical thing is not to overcharge the cells.

-- Jim (, July 22, 1999.

Don't have an answer, but a related comment/question. I was looking into the NiMh type batteries (recommended in a few places because they don't have a batter charge level memory and are supposedly better than the NiCd. However, at one site, they said a special NiMh re-charger had to be used, that not just any re-charger would work. I haven't seen any solar chargers out there for the NiMh.

Confirm, deny, other?

-- winter wondering (, July 22, 1999.


You can *really* screw things up if you don't have the right 'kind' of electricity. For example, a "sine wave" inverter will not damage your delicate electronics (e.g. Stereo, radio, etc.), but a 'regular' inverter can.

Most NiCad rechargers that plug into AC will also be badly damaged by non sine wave inverters.

As for your solar panel / recharger question. Yes, you should be concerned about the voltages, too. It is possible to damage a nicad with a solar panel.

You need to find out what the output voltages are on the panel, and connect a charger that accepts those voltages. There are also several sources for solar panels with rechargers already connected ( for example).


-- Jollyprez (, July 22, 1999.


The info. you have is, well, almost correct. Rayovac, for example, recommends their recharger for their batteries, but it's AC powered. The local electric utility's waffling, muddling, and flat out lying has probably lead you to your recharger that uses direct sunlight. If that's the case, go to Radio Shack for their NiCads or Eveready's are designed for this type of recharger. May power be with you.

-- PJC (, July 22, 1999.

Solly, Jolly, you aren't correct either.

I'll provide the following reference and suggest that you look it up.

Statpower makes both sine-wave and modified sine wave inverters. From their web page, Modified Sine Wave vs True Sine Wave Output, we find the following:

Modified sine wave inverters provide acceptable to good performance with a wide variety of loads and, with some loads, performance is effectively indistinguishable from true sine wave inverters. The benefit of true sine wave inverters is they offer consistently excellent performance with all loads within their continuous and surge power ratings. They operate some loads that can't be operated by modified sine wave inverters and they operate many other loads better.

If you look at the table on this page, you'll find that as far as electronics they note that you may have an audio buzz using a modified sine wave unit. This is a far cry from "damaging your delicate electronics."

There are only a few things that you can't use a modified sine wave inverter for:

Variable speed contol motors

Non-transformer based chargers Note that if your charger runs off ac it may/may not be transformer based. Check it out. A blanket answer isn't the solution.

Laser printers


And, the answer to KLT's question is exactly what was stated: As long as the charger voltage is correct you can use either a solar charger or an ac charger to recharge the battery. The battery does not care whether it's 1.5 volts is generated from solar cells or from a rectifier circuit that operates from 110 vac.

-- de (, July 22, 1999.

Think about it for a minute: these are the little AAA, AA, C, D sized cells. They get recharged using dc voltage in a small "cassette-type recharger, which usually is plug into the 120vac wall socket. The wall socket ac/dc converter doesn't care what kind of ac it "sees" - whether from an invertor or from the power plant.

HOWEVER - The battery does care what kind of "dc" current it is being charged with: the recharge alkalines and rechargeable NiCd's CANT BE SWAPPED in different rechargers. This might be what hte clerk was thinking about.

Tried that (put recharge alkalines in a NiCd recharger) - blew up the batteries, dissolved/melted the charger, got remains of battery "gunk" all over the floor! The current rates (at the same voltage) are very different and the heat generated is very different.

Recharge NiCd ONLY in a NiCd recharger - solar or conventional ac-dc plugged into an invertor or the power plant plug. Recharge the rechargeable alkalines ONLY in a recharger for alkalines, again - it doesn't matter what type of recharger power supply.

-- Robert A Cook, PE (Kennesaw, GA) (, July 22, 1999.

DE, well, not quite.

So called "smart" chargers for power tools [apparently] melt down or even catch on fire. A good friend of mine has a Makita charger that he showed me that had caught on fire and welded the batteries to the charger.

His claim is that this happened when he attached it to an AC socket on his RV that used an older Trace non-sinewave inverter. I've heard many stories about this, but don't have official confirmation.

I'll look around for some and get back to you.


-- Jollyprez (, July 22, 1999.

So why the hell doesn't somebody make a DC-supplied battery charger????

You'd figure with all those 12vdc "RV's" running around, and all those "solar" houses we're supposed to be getting, that there'd be a decent 12v DC charger available, with a "dial-a-volt" front panel setting for the different voltages to the output "universal plug adapter"!

-- Robert A Cook, PE (Kennesaw, GA) (, July 22, 1999.


As I said, one of the cases where the modified sine wave inverter doesn't work is "Non-transformer based chargers. Note that if your charger runs off ac it may/may not be transformer based."

I also said, check out each case, don't make a blanket assumption (one way or the other).

Betcha the Makita power tool battery charger isn't transformer based. As small as those guys are they have to be pure electronic.

Robert, f you'd like to do an experiment, take an alkaline battery charger and use it to charge up some NiCads. I think it will least mine did. It just took a while. It's the vice-versa that gets messy.

The reason that they don't make a 12v dc charger is that someone (me?) would plug it into the ac outlet. (grin)

-- de (, July 22, 1999.

de is right about the transformerless chargers. My DeWalt 12Vdrill's battery charger even has a warning label on it that 120V AC is present at the charger terminals.

-- Elbow Grease (LBO, July 22, 1999.

I have the eight station Ray-O-Vac renewal alkaline charger and also a low priced Radio Shack nicad charger 23-132. Both chargers have the transformer. I took them apart and looked. Mike

-- Mike (, July 22, 1999.

NICAD vs NiMH batteries for Y2K:

NiMH's have been touted as the replacement for NICADs: no 'memory', more capacity/weight & size. However, for the y2k environment they have a major drawback: they 'self-discharge,' lying on the shelf, at a very rapid rate compared to Nicads. In Y2K, you will want to nurse your batteries -- which means you won't be using them unless you HAVE to. That means you'll want to leave as much charge as possible on them -- so you use them sporadically. But in between uses, the charge is disappearing relatively rapidly thus partially defeating your purpose of saving your charge for the next use.

Bottomline: I bought a bunch of NiMH's bec of their rep, overlooking the self-discharge problem. So I went out and bought a bunch more NiCads to use in their place.

BTW, if you buy from common retail sources, Radio Shack believe it or not, is probably your best all-around battery retailer: good prices, good product. But make sure to buy their heavy duty Nicads, not the standard ones. If you want to do much better pricewise buy your nicads from electronics surplus houses like Hosfelt, Electronic Goldmine, and BGMicro.


P.S. What the heck kind of post-y2k scenario do you guys have in mind when you recommend anything OTHER than solar chargers for the newbie's batteries? If you are planning on AC chargers, with or without inverters you must be thinking 'Power Grid Can't Stay Down Forever.' B.

-- William J. Schenker, MD (, July 22, 1999.

Howdy Robert;

Well those MODIFIED SINE WAVE inverters are good for many loads they can cause problems, however for charging Bats you can buy (here at Fry's in San Jose) a 100W sine wave inverter for $20. So use the Big MODIFIED SINEWAVE Inverters for motors, microwaves, and nonsuch. Use the inexpensive sinewave inverter for the "little loads". Or get a Big SolaVolt power conditioner $40 at the local (San Jose local) junk dealer from some old system that bit the dust.

Power for all of US!

-- helium (, July 22, 1999.

Yep yep, de you're right. I need to read more carefully.

ROBERT, there are plans to make battery chargers on DC circuits from Home Power Magazine (

They also have 2 CD-Roms with all their back issues thereon. VERY cool. Includes bicycle generators, active & passive solar, wind, you name it.


-- Jollyprez (, July 22, 1999.

I have solar rechargable nite lites in my yard. They have an everready AA battery that has been charging every day now for over a year. Still going strong!!!!!!

-- freddie (, July 23, 1999.

C. Crane--I've orderd about $350-400 worth of stuff from C. Crane and have been highly satisfied with service, price and product. Am most impressed by honesty of advice and information. Catalogue on-line at Example:


Nicad batteries are one of the most misunderstood consumer products. Manufacturers are guilty of gross misinformation and product design. If you send us a self addressed stamped envelope we will send you free literature on how to manage your Nicad batteries properly. Be sure to request Nicad Literature. Our batteries have from 50% to 280% more usable power than the typical Nicads you buy at your local discount house. We do not recommend nicad batteries in the 9 volt size because they are under powered. If you use a set of batteries more than 3 times a year we recommend you invest in nicads and a charger. You must be willing to perform simple battery duties to get the most out of your batteries. Home Power Magazine rated our batteries and information literature as some of the best of several companies they reviewed. Once you try our batteries you will be amazed at how much money you save and how easy it is to manage your investment. Its great for the environment also ( P.S. mah = milliampere hour).

Nicad Prices:

Dsize (4000mah), Item #RD ..... $6.95 each

Csize (2400mah), Item #RC ..... $4.95 each

AAsize (850mah), Item #RAA .. $2.00 each

AAA"size (220mah), Item #R3A $2.00 each

Batteries and Chargers


Comes with (4) AA batteries. Nickel Metal Hydride batteries are almost twice as powerful as NiCad batteries. Best for high use situations because they lose their charge at 30% per month without use. NMH batteries should never be charged in a regular charger because they might overheat and be damaged.

Item #NHC .......... $39.95

Nickel Hydride "AA" Battery

Item #NHA ........... $3.00


This high powered solar charger will charge two nicad batteries of the same size at the same time, (D, C, AA, AAA). It puts out about 150mah and about 5 volts. All of the other solar battery chargers we tested were unsuitable because their voltage was too low. Made in China.

Item #SBC ........... $14.95

-- Old Git (, July 23, 1999.

So why the hell doesn't somebody make a DC-supplied battery charger????

You'd figure with all those 12vdc "RV's" running around, and all those "solar" houses we're supposed to be getting, that there'd be a decent 12v DC charger available, with a "dial-a-volt" front panel setting for the different voltages to the output "universal plug adapter"!

-- Robert A Cook, PE (Kennesaw, GA) (, July 22, 1999.

This is exactly what I built. The "dial-a-volt" is just a Radio Shack panel mount voltmeter in parelell with a large variable pot I salvaged from an old TV. Nicads, alkaline and other rechargeables require slightly different voltages and current levels. The nicads use a higher voltage and a faster current flow because they discharge faster. This voltage makes the chemicals in the alkalines outgas and bulge or burst the battery. Slower rechargers work better and are less stress on the battery. As for the voltage spikes in non-sine, multivibrator type inverters, I have run my computerised synthesiser on one for many hours with no ill effect. The audio buzz from the spike reduces if the load on the inverter is increased, I suspect the additional inductance in the circuit serves to absorb the voltage spike of the multivibrator, but I am speculating. However it makes an unholy noise on my ham equipment, so I am inserting a couple of large caps and one of those noise coils like are used for car stereos. The inverter will also run much cleaner if you use that grounding screw on the back and affix it to a good earth ground. The house electrical ground or a metal water pipe connected to earth are good.

Forrest Covington

-- Forrest Covington (, July 24, 1999.

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