Rechargeable Batteries Test

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peartree

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All the comments I've read (and the original tester) are ignoring something very important: How many times can that pack of batteries be recharged?

It does no good to have a wizard set of batteries if it's going to be unchargeable after a dozen (or a hundred) runs.
 

caspian21

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[citation][nom]peartree[/nom]All the comments I've read (and the original tester) are ignoring something very important: How many times can that pack of batteries be recharged?It does no good to have a wizard set of batteries if it's going to be unchargeable after a dozen (or a hundred) runs.[/citation]

Not true. Just read up a few posts and the author notes how it would take many months of testing to get this info. He admits it would be beneficial to know but not reasonable for him to commit to such an undertaking.
 

ceomrman2

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Ug, what a craptastic effort. I'm really unimpressed with Tom's. Some of these articles are just ridiculously weak, like this one. If the author had just searched for and read a few other articles about rechargeable batteries, he or she would have been able to write a much better article. This one deserves a "B" for presentation but a "D" for content, as is usually the case with Tom's. It avoids being totally worthless because the author did make a few useful points, like about the voltage of the new chemistry batteries and the slightly larger diameter of some of them.
But why in the world would you test each battery only with its included charger? Who buys four AA's with a charger each and every time? You buy one bundle, maybe two, and then you buy just batteries. Who needs a half dozen chargers plugged in around the house? So why not test the batteries in the other chargers, or better yet, use a high quality charger to get accurate readings off the batteries?
The use of a decent charger (something like the Maha WizardOne or similar, $50) would have been obvious from doing any amount of background research. It would have let the reviewer automatically charge batteries properly with high quality electronics, ensuring they hold as much as they can. Good chargers also tell you the battery's true capacity (in MAH) by draining them, charging them, and then draining them again and automatically keeping track of the total juice they held and the voltage at which it was delivered.
Using a decent charger would also have let the reviewer judge the bundled chargers. Maybe a bundled charger is to blame, not the batteries. So what good is it to pan Energizer brand batteries based on the Energizer charger? What if you're at the store and there's a super clearance on Energizers and you already have a non-Energizer charger at home? Well, my experience tells me I should buy the Energizers (the pre-charged type, at least) because they perform very well, in general, using my WizardOne. They hold between two thirds and 100% of their claimed MAH capacity, compared to about 90% for the Eneloops. If I relied on Tom's, though, I would pass up the clearance sale, thinking that the Energizers were bad when they really may be good. A smarter charger also is likely to use less energy, as its more advanced charge state circuitry knows when to stop charging the batteries and gently trickle charge them to keep them up. It can also easily bring weakened batteries back to life with drain and recharge cycles, which can really help, especially if the batteries you just bought were sitting on the shelf for a year and a half. If the point is to have cheap, never-ending batteries that you very rarely need to throw out and that last a really long long time, then read Consumer Reports to begin with (yup, CR's article was far more useful than Tom's). Better yet, check the several excellent websites out there that have informative articles on the topic.
 

Tomsguiderachel

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ceomrman2--As the editor of this site, I would not allow these rechargeable batteries to be tested with chargers other than that of the same brand. I understand your point completely--you can get more mileage out of these batteries with another charger--but we must test products as most consumers use them. And most consumers buy rechargeables with a matching charger. Maybe next time we do this type of article we will use both the charger that came with the batteries AND one popular and well-rated third-party charger. But then, no doubt, you will chime in to say that we chose the wrong one.
 

Tomsguiderachel

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[citation][nom]timbrwlf56[/nom]This review falls short of even being an attempt at a good article on batteries. You completely missed two of the best brands on the market, Tenergy and Powerex, the Powerex AA size cells are rated at 2700 mAh and blow away most of the ones you reviewed.Similarly you failed to discuss *why* most of these chargers produce excessive heat in the batteries. Most of them are doing a quick charge, which is trying to stuff as many electrons back in to the battery as reasonably possible at high speed. This has two negative side effects, one it overheats the batteries making it dangerous to leave them charging unattended. Two, the excess heat degrades the internal chemistry of the battery over time causing it to lose the ability to hold a very good charge.Powerex also sells a variety of quality chargers that offer two modes, a standard quick charge, and a slower trickle charge. The slower trickle charge charges the batteries much less aggressively over a longer time, and doesn't heat them up nearly as much and cause the degradation of performance over time. Get a set of good quality batteries and a charger that supports slow trickle charging and you'll be set for years.[/citation]
If Tenergy and Powerex have come out with a new battery technology in the last six months then yes, we messed up. But this article was focused only on products that were new to market. This is true of nearly all Tom's Guide reviews. I'm sorry if you don't like that, but we do focus on the "new" when we do reviews, and not simply on the things proven to be "best."
 

ossie

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TGR, thanks for pointing out again the obvious:
Why should a consumer be educated, and informed, capable to do the right choice, when everything can be dumbed down to the most common level of ignorance? He would stick out, as a sore thumb, from the mass ignorance, and complacency, which characterizes the "modern" society.
If that's what you're after, then you deserve an A+.
No wonder TH/G, and the world, is going down the drain...

Poor Tom (actually it seems he's wealthy enough after the BoM deal) would turn over in his grave (hopefully still alive, enjoying the cash), if he could see what his hard work transformed into...

Thomas, schade dass du's aufgegeben hast, jetzt stinkt's zum Himmel!
 

WheelsOfConfusion

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[citation][nom]bri-guy[/nom]Actually I had contemplated doing exactly this and I tried it out but the camera I was using was unrealiable in the number of shots it would take on a set of batteries. Sometimes I would get 650 shots, other times 350 shots.[/citation]
That might be that you're fast-charging the cells. What often happens is one battery goes bad and doesn't hold a full charge, but you've got a set of four so sometimes you're using the bad cell and sometimes you're not.

Fast "15 minute" charging kills your NiMH batteries, and even if you have a charger that can refresh-cycle them they'll never work the same again.
All the Eneloop and other "low self discharge" NiMH batteries use a slightly thicker membrane to keep ions from being exchanged inside the cells. That means they last longer in storage, but it also means there's less room for materials so there's less capacity to store a charge. You trade runtime for shelf life.
I have an old set of 2500mAh Energizers that are still going strong after a few years of light use, and I also have a new set of Duracell 2650mAh batteries that are working out well: they let my Roboraptor stomp around a bit longer before he starts stumbling over the carpet. I always use the old Energerizer 8-hour charger because I'd rather keep these batteries around for a while.

 
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This has to be one of the worst Toms articles in recent memory. Firstly I do like many things about the review - heat of batteries post charging, approximate cost of charging and any promotion of an environmentally friendly product to the gadget lovers that are Toms readers is a good thing.

Now for the weaknesses, the article discusses the carbon effect of charging re-chargeable but ignores the carbon involved in the manufacturer of disposables, granted it does acknowledge the 'environmental cost'.

The review considers batteries new to market however Eneloops have been around since late 2005 - http://en.wikipedia.org/wiki/Low_self-discharge_NiMH_battery

No serious reviewer can compare actual charge/ discharge cycles lifespans based on manufacturer claims, maybe the manufacturers that claim hundreds of uses actually mean 900 which makes talking up the 1,000 cycle claim kind of pointless, maybe those that claim hundreds are just more honest?

How can the NiZn batterries 1.79V be described as better? Its not better when it blows up your devices due to excessive voltage! Not only do they stupidly exceed the AA voltage specification they exceed the dimension spec, shouldn't even have been included in the review imo and the advice of not putting them in your flashlight completely ignores the potential damage to far more sensitive and potentially expensive devices.

The fact that the article completely ignores the issue of self-discharge does the readers of Toms a great disservice, as the comments here show most readers actually had more knowledge of rechargeable prior to reading the article than after - not really how its supposed to work…
 

13thmonkey

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Energizers are rubbish, if I hadn't been using ansmanns for a good while they'd have put me off rechargables for life. My Ansamanns are great, hold a good charge, and they have hybrids now. Will look at the eneloops definately next time I need some though. Its too bad that they are selling energizers as temptation items in stores, i'm sure there are many that think the concept is poor because the batterys are soo bad.
 
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Terrible article. They miss the point of the sanyo and rayovac batteries. They will hold their charge for months with losing little power. They are not like regular rechargables.
 
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Anyone thought abut getting SOLAR AA/AAA battery charger? Then you get some serious eco-friendly action going! ;)

Solar battery chargers are cheap these days, and easy. Load them up, put in sunny windows, and in 2 to 5 days fully charged AA's. So if you are not in a hurry...
 
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I've been using Eneloops every day on pretty much everything I own for two years. They are robust, last long, don't discharge over time, and are inexpensive compared to both disposables and better known rechargeable. And like most rechargeables, they are green.
 
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It's hard to believe the author of this review spent the time to actually test the batteries and read the data on the side of the batteries. I just tested the Powergenix NiZn AA charger myself on the four NiZN AA's that came with it. Here's what the reviewer got wrong.

1. When the batteries are fully charged, the two red LED's didn't turn green. They just went out, as it clearly says in the manual will happen. The reviewer just made up the part about them turning green. Not a big deal, but it makes you wonder how much else he made up.

2. The NiZn AA's are not rated for 2500 mAh. That's what good-quality NiMH AA's are rated. But if the reviewer were good with details, he would have noted that the NiZn AA's are clearly marked 2500 mWh. A milliwatt-hour is not the same as a milliamp-hour unless the voltage is exactly one volt. Anyone conversant with Ohm's Law probably also knows that volts times amps equals watts. So these AA's at 1.6 volts are rated at 1562.5 mAh. Which isn't an impressive number by itself. But for my money, it's good enough, given the superior voltage.
 
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After reading all the comments here, I came to two conclusions:

1. The difference between mAh and mWh is extremely important. Author goofed on this point, but it's an easy mistake to make. Made it myself when I bought these at Big Lots for almost nothing.
2. It appears that a lot of the people who play around with batteries are, plain and simply, jerks. They may be knowledgeable but any knowledge they have is more than negated by their attitude.

I would have liked to see some actual test data. One thing is clear: these are good for any device whose performance is sensitive to voltage, like a GPS unit. Mine simply won't run when the voltage gets down much below 1.1 volts. You aren't going to get a higher voltage than NiZn unless you go to lithium, and these compare very favorably on price.

Bottom line is, these batteries are an excellent choice for some niche applications, applications where a NiMH battery might not last long because it can't hold the voltage up high enough.
 

Hard Line

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Please don't take this the wrong way... but do you realize this thread was necro? lol last post was over a year ago lol
 

nathyn

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It does indicate when finished there are little red lights on the bottom. They are only 0.005 inches thicker than standard alkaline batteries and sockets have an extra 0.005 inches on either side of an alkaline battery and .0025 inches on either side of a NiMH battery, which means the NiMH batteries fit just fine in sockets. They only took 4 hours to fully charge for me and where a little warm. When charging 4 it used 13.5 watts of power and each battery holds 3 watts of power meaning you use 13.5 watts to charge 4 from dead to full and you get a total of 12 watts between the batteries. They powered a CD player for 29 hours and 53 minutes and a flash light for 11 hours and 46 minutes. I have some that I have charged over 700 times and they work just like the new one's I just bought.
 
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PowerGenix NiZns have too high a voltage. Some of my cells even have up to 1.8V! You can damage some devices by using these things, they're worthless. You can bring the voltages down to a safe level by mixing them with NiMh's but why should you? Why can't they make them 1.5V.

Duracell NiMh's are horrible, they self discharge so fast its not funny. I'm suspicious of the "Made in Japan" label.

Rayovacs are nothing special, typical low quality chinese made batteries, high self-discharge and low capacity.


Oddly enough my set of ancient Panasonic 1500MaH turn out the be the most reliable ones, with moderate self-discharge and they seem to be getting stronger as I recharge them over and over again. I've had them for years.

I'm getting some Eneloops to see if they're really all they claim to be.
 
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