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AA Batteries : are re-chargeables worth it over alkalines?

R

radhak

Senior member
Couple of years ago I gave up on the re-chargeable AA batteries. I had bought a large batch of NiMH, and they never delivered as promised. They were only 1.2V - in itself a problem with some devices, and most got nowhere close to the 1000 recharges; and they also were usable for much less time (between recharges) than regular alkalines.

The hassle of not knowing at crunch time if the batteries in my hand would work, or for how long, pushed me back towards the use-and-throw AA's.

Yesterday I picked up a 40 pack Duracell AA's at BJ's for $15 after tax.

I have heard that the best rechargeable are the Eneloop, but the charger has to be bought separately; the La-Crosse BC700 was recommended, or its fancier upgrade BC1000.

Comparing pure up-front costs seems one-sided : the Duracell cost 37.5 cents, while the Eneloop seem to cost around $7.50 each (spreading the charger cost). But if they are recharged at least 20+ (they better!), they easily get to be cheaper.

The issue would be if I need more that 8 cells simultaneously (as I do). A rough estimate around my house is that I might need around 20-25 AA batteries at a time. That increases my upfront cost a lot, and also the hassle of charging all of them, tracking which ones are charged and which aren't, etc.

And the biggest unknown is how they compare in longevity of a single use against the alkies. That becomes particularly annoying when using in the wall-clock high up on the wall, or in the fire-alarm/smoke-detectors up on the 16 ft high ceilings!

So does it even make sense to move to re-chargeable? Which ones? Are the LiON batteries any better?
 
I always end up going back to alkalines. Recharging batteries always comes at a time when you need batteries quickly or when you have to leave the house. If I leave the batteries plugged in and charging, it goes unused for several weeks or months. Strange how life work. 🙂
 
Rechargeable batteries are a PITA. They're good for some things, but not others. Solely on cost basis, I think they're always a better deal, but aren't always worth the hassle.
 
I love my eneloops. I use them for remotes, wireless mouse/keyboards, and lately my kid's toys.

They seem to have a longer charged "shelf" life too. I can fully charge them and put them back for when I need them a couple months later.

I use a cheap charger that came with an energizer pack I bought a while back, it works fine, but I would like to upgrade to a nicer one that can charge 1 at a time.
 
The issue is today's rechargeable are built cheaply and don't last. Part of that is to go more green, but what's the point of building something cheap to go green when if it was built well it would not have to be thrown out in first place?

The fact that they're 1.2 or 1.3v instead of 1.5 is a big issue with lot of devices too. I have a corded phone with digital display that runs on batteries only, it takes 3 of them. So naturally the phone expects 4.5v but if I put rechargeable it only gets 3.6. Wont work.

When I was a kid I had tons of nicad Panasonic batteries for toys and other gadgets as I grew older, those things were the best. They had no recharge limit, I used to abuse those things so bad, and they still continued to work. When I got into electrical and played with motors and that kind of thing, they always delivered.

Alkalines actually can be recharged too. It's just that the chargers are not designed for it and may possibly cause them to burst, or otherwise cause some damage. There's considerations to take if you try it, but it does work.
 
It only makes sense to use rechargeables in devices that frequently go through batteries. Let's say a rechargeable costs 10x what an alkaline costs. If you change the batteries in your TV remote once a year it will take 10 years to pay back, not too attractive. The rechargables will also self discharge faster than alkalines so you'll find yourself charging them more often than once a year.

On the other hand, think about an xbox controller that goes through a set of batteries a week. You'll come out ahead in only 10 weeks. (ignoring the cost of electricity) I do use rechargeables but only where it makes sense.
 
I mostly use rechargeables myself. Have the BC700 charger and a handful of this that and the other type of battery. From harmony remotes, xbox controllers, a "weather station", and a few other gadgets, whenever I need batteries I just swap them with what I have in the charger, or next to the charger that have already been recharged. Never seem to have a problem.
 
I use Eneloops in mice/keyboard, Wii controllers, digital camera and some remotes (like my Harmony). I use regular alkaline for clocks, fire detectors, tv remote, etc.
 
I still keep a few alkalines around, just in case, but I primarily only use lsd nimh (eneloops or rayovac hybrids). I've had my batteries for several years now, and still work great. I still use the cheap ass charger that came with my first set of batteries. It doesn't seem to harm the batteries too much... at least not enough to get me to shell out the money for the fancier charger.

The main advantage of rechargeables for me, is that I always have batteries available. Several years ago when all I used were alkalines, I'd often run out at the worst time possible. Now, I keep a couple charged, and are always ready to be used. Combined with low self discharge, it's the ideal situation for me.
 
I use them in my camera flash because they don't take nearly as long to recharge the flash for the next shot as alkaline batteries do.
 
I like rechargeables because it feels like I'm not wasting... but for ~$10-$15 for a four pack, starts getting expensive.

I don't use many battery operated devices anymore, so my collection has gone to remote controls.
 
If you buy the right eneloop package you get a decent charger that can charge one cell at a time and some batteries. I have the model NC-MqNO5U charger that came with 4 AA batteries. The charger will also recharge other brands of hybrid or low self-discharge NimH batteries.

Even if they only provide 100 recharges that's still cheaper than the non rechargable alkalines.

As long as you remove the charger from the outlet after the batteries are charged, I think your additional energy use should be minimal.

For maximum convenience you're probably going to need at least twice as many batteries as you will have in devices at one time. that way you can rotate the cells through the charger and have at least one set of charged batteries ready to go.
 
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Happy to note others find rechargeables just as painful...

But a couple of good suggestions there : to use re-chargeables for the devices that need most-frequent turnover of batteries. I think my new hobby of RC Heli would qualify (each remote takes 6 AA, and I have two), as would the Wii, and the external flash for my DSLR. The rest might run on alkies for now.
 
alent1234 said:
no because you still have to pay for the electricity you recharge them with
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Depends on the number of batteries you tend to use per month/year.


the more you use the better off you may be with rechargeables.

http://www.thesimpledollar.com/2008/04/25/are-rechargeable-batteries-really-cost-effective/

Maintenance Cost of Rechargeable AA Batteries
I put the charger on my handy Kill-A-Watt to see how much electricity is actually used in a recharge – and I was surprised. The battery recharger ate up 0.02 kilowatt-hours per AA battery recharged. Since I would be recharging 120 AA batteries in a given year, the recharger would eat up 2.4 kilowatt-hours per year. With electricity costing $0.10 per kilowatt hour these days, that means the charging cost per year for the rechargeables is $0.24.
Click to expand...
Kill-A-Watt = http://www.amazon.com/gp/product/B00009MDBU?tag=thesimpledo0c-20

As this link shows.

However you don't have to by an expensive charger the eneloop chargers that are come with their batteries in certain packages are good enough.
 
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lxskllr said:
Rechargeable batteries are a PITA. They're good for some things, but not others. Solely on cost basis, I think they're always a better deal, but aren't always worth the hassle.
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Get a 10 unit recharger and leave them in there when you arent using the things.
 
all depends on the amp and volt needs of the application. nimh is much more suited for high-current devices. alkaline voltage starts higher but drops almost linearly while nimh will stay at 1.2v until it's nearly dead. i think alks are mostly suited for clocks and basic tv remotes
300_discharge-graph.jpg
 
alent1234 said:
no because you still have to pay for the electricity you recharge them with
Click to expand...

They're not worth it for those challenged by math. A kilowatt hour runs about 10 cents. Recharging a pack of 4 batteries doesn't draw anywhere near 8 amps on your household 120V circuit for one continuous hour. (That would be .96 kilowatt hours of electrical energy consumption.) If it did, then it would work out to roughly 2.5 cents per recharge. The actual cost is, obviously less.
 
SonicIce said:
i think alks are mostly suited for clocks and basic tv remotes
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The newer hybrid or low self-discharge NiMh batteries work in those devices just as well as regular alkalines. Older NiMh discharged after only a few days. the newer ones can be used in remotes for 6+ months
 
alent1234 said:
no because you still have to pay for the electricity you recharge them with
Click to expand...

You pay for the gas to drive to the store to buy new alkaline batteries, too. That's probably a higher cost for most people than the fraction of a cent of electricity that it takes to recharge batteries.

I concur with what the other posters are saying: Use rechargeables in things that go through batteries quickly (digital camera, RC stuff), and stick with alkalines for your TV remote and the like. Rechargables actually work better than alkalines for high current applications.
 
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Too much of a PITA for me...I have a BC1000 just collecting dust with a crap load of various batteries just sitting around...didn't help any that I can get pretty much unlimited free batteries from work (legally😉) One of these days I'll probably sell all of them, if I get around to it:\
 
Good rechargeable like Eneloops are well worth it. I still keep alkalines for quickly throwing in a dead flashlight during a power outage or something, but after having one leak and ruin a $20 Maglite, I stick with lithium primaries and others.
 
DrPizza said:
They're not worth it for those challenged by math. A kilowatt hour runs about 10 cents. Recharging a pack of 4 batteries doesn't draw anywhere near 8 amps on your household 120V circuit for one continuous hour. (That would be .96 kilowatt hours of electrical energy consumption.) If it did, then it would work out to roughly 2.5 cents per recharge. The actual cost is, obviously less.
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It's better than that.

NiMH charging efficiency is about 66%. A typical cell will deliver 2 Ah of power at a fairly flat 1.2V, for 2.4 W-h. Therefore it takes 3.6 Wh of power to charge each cell all the way up from dead flat.

At 10 cents a kWh, it would take almost 3000 charge cycles to hit a DOLLAR of electricity.

Now, maybe you'll lose some more efficiency if you fast-charge or have a crappy charger, but that's still thousands of charging cycles to get to the cost of a single alkaline battery.
 
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