Should I go for rechargable batteries?

I use my CD/MP3 player a lot when I’m out and about during the school year. Last spring, I got a lot of use out of the great chirstmas gift. However, I also went through four AA batteries in less than a week. So I’d be going through a lot of batteries. While at the store last week, I noticed the rechargable batteries they had. It made me think that with the usage I put, four AA batteries and a charger might pay for themselves after a while. Could some battery-experts here give me some advice as to purchasing rechargable batteries?

I’d recommend rechargable batteries. Preferably NiMh.

(unless someone here knows of higher performance batteries)

I’m no expert, but I use rechargeable batteries in my Visor (AAA’s) and my MiniDisc player.(AA’s) and like them. I use both rechargeable alkalines and NiMH, but I don’t really notice any difference between them. My Radio Shaque charger handles both chemical types and AA’s and AAA’s all in the same slot, and it has 4 slots, so it’s pretty convenient… I’ve had to replace a few of time–they just stop taking a charge after a while. But the expense is nothing compared to normal batteries.

They do not last as long as normal batteries, of course, (about a week of use on my Visor, vs. maybe a month to two months). It may be that your level of use is so high that the shorter lifetime of rechargeables would be too frustrating. OTOH, if you just get in the habit of swapping your CD player batteries for the ones in the charger each morning or evening or whatever, it might work fine for you. (Memory issues remain a matter of debate.)

I can compare rechargable alkaline AA’s with non-rechargeable AA’s when used with a cheap, consumer-grade digital camera.

Non-Re’s: typical 100 shots
Re’s: typical 50 shots

Non-Re’s, shelf life: years, very slow discharge
Re’s: discharge completely in a few weeks (but not at a linear rate).

So while my choice to power a TV remote, for example, is definitely non-rechargable batteries, due to the extremely low power drain and very long shelf life (a TV remote uses about as much power as a battery sitting on shelf), rechargables are a must for the digital camera or MP3 player.

A set of 12 rechargables has lasted me over a year so far (about $20 total), where I estimate I would have had to purchase 320 standard alkalines (maybe $400) otherwise.

Of course, I have not factored in the electricity from the wall socket. I assume it is only pennies. Anybody know a simple way to calculate the KWH used, short of hooking up an ammeter to the recharge box?

Here’s how I might do it. The recharge box says 6 watts. I assume that when the light goes out, it draws almost 0 watts, and in the absence of other info, it draws 6 watts continuously until done.

Let’s say 1 hour to charge 4 AA’s. That’s .006 KWH (6 watts * 1 hour). At 8 cents per KWH, the cost to recharge 4 batts is then $0.00048.

Anyone know if this is a valid computation?

Rechargeable Alkies are about a dollar each, cheap compared to Nimhs, & do the job
pretty much the same for that sort of thing. For a high drain gizmo like digital cameras you
need Nimhs. I guess.

Actually, NiCd’s are better for charging a Strobe in a camera, since they have lower internal resistance. Airsoft gunners, who need CURRENT, all use NiCds.

OTOH, NiMH’s have greater capacity.

Stay away from the GRANDCELL or GP brand (I heard they are called LEAP now.)

I was in the neat and unique situation of having to buy a BUNCH of rechargable Double A’s. Like, 30.

I bought 15 different brands. Radio Shack, Energizer, RayoVac, you name it.

The GP’s/Grandcells wore out the fastest (Wouldn’t take a charge)
the quickest.

I noticed, like, three months into the test that the items with the Gp’s were petering out faster than the rest.

Stay away. Unless you get a good price.

No comment on who’s next. They all look pretty good, IMHO.

If I had to buy another 30, all the same brand, I’d buy by price, except for the Gp’s.

OH: And get a good charger. A GOOD ONE. if you ever take your batteries out of a charger and they are warm, you have a crappy charger.

The big difference between NiMH and NiCd is that NiCds are vulnerable to the memory effect, while NiMHs are not. The memory effect happens when you charge a battery that is not nearly or completely drained. Charging a battery that has a lot of charge still in it will slightly damage its charge capacity (not much damage if you do it just once, but it builds up).

the memory effect is actually what is know as voltage depression and also happens in Nimh but not as fast.

For digital cameras, the drain isn’t necessarily the flash, but taking pictures, storing them, and running the LCD. NiMH are the way to go for DCs.

Another concern is disposal, alkilines fill up landfills with some nasty metals, rechargables (while eventually going to the landfill) produce much less waste. Recycling programs are still fairly hard to find 'round my area.

A great set is the Maha charger plus batteries. Go to for some great deals and a very good FAQ.

How about running a CD player, which is what I would use.? I have heard that power loss from NiCads (and NiMh I guess) is generally sudden, as opposed to a gradual power loss in alkalines. I know often I have alkalines that still have some charge, but are too weak to spin the CD fast enough for it to work properly. What would you reccomend?

CD players aren’t exactly high-current devices. I’d say NiMH batteries are suitable.

It’s true about the sudden power loss. The voltage of alkaline batteries decrease gradually through use. The voltage of NiMH and NiCd remains fairly constant, then drops off suddenly at the end. This usually isn’t a problem. Generally the only effect is that it makes the battery meter (if your device has one) unreliable, because the device can’t look at the voltage and tell how much charge remains.

Nimhs should have a rating on the package. Be sure to check this. It would say something like
1800, 1400, etc, lets you know how long they hold a charge. Even my lithiums in my Sony camcorder
need to be charged if not used more than a month.

That is true of NiCds, and may be true of NiMHs, but according to RayOVac, rechargeable alkaline batteries are best kept charged. They advise putting a slightly-discharged batt on the charger immediately instead of running it all the way down.

They may be right. I have some AA Alkaline rechargeables a year old, in constant use, and put on the charger every 3 days or so whether they have been used or not. They seem to be as good as new.

I use NiCads almost exclusively. I keep a lot of charged ones handy. I used to fully discharge them by leaving them in a flashlight or little transister radio. The high-capacity NiCads from Radio Shack are a little pricey but I thought a bit more dependable.