I go walking in a mall a lot and carry a portable radio. A gentleman friend suggested I purchase some rechargeable batteries, but I read many years ago that rechargeable batteries don’t last long because of a “memory” problem.
Is this true of the new “AA” rechargeable batteries, like the Energizer or Duracell? Somewhere one of these brands said you could re-recharge them more than a thousand times without much power loss.
Is this true?
I can only summerize from my Consumer Reports .
Rechargeable batteries are cost-effective in your radio. as long as you are using them on a frequent basis. The batteries lose their charge over a long-storage period of time. Sounds like you could make effective use of them.
If you buy and use alkalines currently, remember to buy them by price, as they tend to all have the same lifespan, without regard to brand name, etc.
Here’s a link to Cecil’s article on battery memory:
http://www.straightdope.com/columns/990312.html
I’ve been using rechargeable ni-cads for years without experiencing the problem.
I can report that I’ve got good use out of the AA cells for Walkmen & a battery-powered alarm clock for over 5 years.
The clock talks to you when you push the big yellow button. Tells me the time without my having to put on glasses & turn on the light in the middle of the night. Handy to have, if you’re as nearsighted as I am. Crows like a rooster to wake me up, too. {Better than some damn buzzing alarm.}
Related question: Why do some gadgets say not to use rechargeable batteries? Is there a real danger or is it all just some giant conspiracy involving electronics manufacturers, Duracell and probably the Trilateral Commission?
We finally gave in and bought flodjunior a GameBoy Color for his birthday on Monday (he’s only been bugging us for one for, what, two years now?). The instruction manual says very clearly “Don’t use rechargeable batteries”. Have we just committed ourselves to supporting the battery manufacturers until the kid goes off to college? :eek:
Nicad cells have a nominal voltage of 1.2 volts, while alkaline (and the old carbon-zinc) are around 1.5 volts. These differences are due to the chemistry in each type of cell. Thus, four AA alkalines will add up to 6 volts, while 4 AA nicads will only be 4.8 volts. A “9V” nicad is either 7.2 or 8.4 volts, depending on how many cells it contains.
Some equipment is sensitive enough to not work with the lower nicad voltages. Some electronic devices will work with either, as long as it knows which you’re using (often all it does is adjust the “low battery” warning trip-point).
Arjuna34
Alkaline batteries are recommended for most computerized electronics due to their higher sustained output. They tend to deliver rated current flow until just before they run out. NiCd batteries tend to due more of a gradual fade-out. That makes them more suited to devices like radios. Computer-like devices tend to become unstable when the voltage level drops below a certain threshold, which is usually only slightly lower than the rated output of a fresh battery. Amplifier-type devices (radios and CD-players) have a built-in compensation in the volume control.
Alkaline batteries are also recommended for flashlights for the same reasons, in addition to the longer shelf life they offer.
Actually, nicad batteries have a flatter discharge curve than alkalines. They tend to die pretty abruptly.
Arjuna34
For digital cameras, you shouldn’t use anything but rechargable NiMH batteries. The new ones are 1500 to 1600 mAH and will last far longer than any alkalines.
Also, you’ll burn through a set of alkalines in 30-45 minutes of use on a current digital camera. That’s a staggering cost in a short period of use.
Um, why wouldn’t you recommend rechargeable lithium batteries? They’re generally better in every respect to nicad and NiMH (except for initial cost).
Arjuna34
If you want portable power you can get one of those big battery packs that clip on your belt. Cost about $50.00 now & you can plug in a huge assortment of things to them, including laptops, video cameras, digital cameras, etc. & have power for hours.
Do lithium rechargables come in AA? That’s what my camera uses (and most/many others). It’s common with all the other batteries in my life, so I can swap batteries with everything else. Also, if you in a remote location (I travel a lot) you can almost always get AAs. If the lithium rechargables are non-standard, I’m out of luck.
Some cameras come with non-standard sized lithium rechargables, but not a seperate recharger. That means you have to use the camera to recharge the batteries, which is a pain if you want to swap batteries and recharge the spent ones at the same time. I believe (no facts, I can’t find any recharges online) that there aren’t many recharges for non-standard (AA, AAA, D) batteries.
http://www.thomasdistributing.com/nimhbattery-faq.htm is an excellent FAQ about NiMH batteries. For $32 you can get an excellent Maha recharger (with 12V car adapter) and a set of 1600 mAH batteries.
My camera (Olympus D-490) came with non-rechargable lithiums that I will keep as an emergency backup since they won’t lose their charge. But all the camera users recommend NiMH as the only real option.
Ah- for some reason I was thinking of digital camcorders, which tend to have specialized battery packs, not digital cameras, which tend to use standard AA sizes. Since a lithium cell has a 3V nominal voltage, you won’t find too many AA lithium cells 
Arjuna34
Alkaline AA cells typically have a rating of 2800 mAh, which is about twice what NiMH cells are rated at. That said, the rate of discharge plays a large part in determining how much of the power is actually used, so in some cases NiMH cells may actually last longer. Keep in mind, however, that alkaline cells discharge on a linear slope, so that not all of that power will be at the same voltage. They start at 1.5V and discharge down to about .9V, when they’d be considered dead. NiMH batteries, on the other hand (as was mentioned earlier) tend to maintain pretty much the same voltage until right before the point of being used up. Therefore the 1.2V rating of a NiMH or NiCd cell close to the average of the expected voltages from an alkaline cell, and should work well in most applications where the batteries won’t be sitting around for a long time unusued (or minimally used). I’ve also read on one of the battery websites somewhere that keeping fully charged NiMH batteries in the freezer will allow them to maintain their charge longer.
You can get pretty good deals on NiMH batteries and chargers on eBay. Supposedly Radio Shack also has a good deal.
Well, everybody else seems to have covered the battery question fairly well, so let me take care of the kiddie stuff. I have a GB Color (great for long flights and drives) and have used NiMH batteries with no problem whatsoever. I’ve also used the rechargable battery accessory that fits into the battery compartment, but actually powers the GB through the AC adapter jack at the bottom of the unit. The “no rechargable battery” warning might have been put there to boost sales of these things or </conspiracy theory>, I may have yet to see battery related damage to my GBC. Only time will tell. (Though it hasn’t in the year I’ve had it.)
The Nikon 880 digital camera uses a lithium-ion rechargable battery that costs about $35 and the charger is a bit over $50. They are smaller than 4 AAs and have a little longer life, but IMO don’t make up for the extra expense and need to carry around two recharges; I use AAs for other stuff.
That’s why I wouldn’t buy a DC that didn’t use AAs. Other applications might make lithium-ion batteries the right choice.
The NiMH last 2-3 times longer in a DC than Alkalines. I assume this is for the reasons stated by frogstein. One nice feature of the Maha recharge is that once you reach full charge it switches to trickle charge and you can keep the batteries there for up to a month, so you always have fresh batteries.