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Post by Ripper on Jan 26, 2007 19:13:32 GMT -5
I need some tech advice on rechargeable batteries. The batteries I have now are Panasonic 2100mAH (AA) The new ones I bought by Energizer are 2500mAH, but still AA. What does that number mean? I feel sooooo lost!
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Post by sumgai on Jan 26, 2007 22:05:28 GMT -5
Search-and-Rescue Fodder,
That number is a performance indicator, telling you what that battery can do in terms of delivering power (or correctly speaking, amperage). It's a little messy, but for the most part, you simply take the industry standard of 20 hours, and divide that into the rating. In your first example, the 2100 mAH battery, you divide 20 into 2100, and arrive at 105. Since you started with milliamps, that's what you're looking at now. But just for reference, that could also be stated as 0.105 Amps.
That result is how many amps (or milliamps) you can safely draw from the battery, at any given moment in time. If you place a load on the battery that tries to draw too much more amperage, the battery might cope with it OK, but the chances are good that it will contract an ulcer of the fatal kind.
All of this means that your first example battery will let you draw 105 milliamps or so, for up to 20 hours. After that, it's re-charge time.
HTH
sumgai
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Post by ChrisK on Jan 26, 2007 23:21:52 GMT -5
Just make sure that they are the same type if you're using the same charger.
These sound like Nickle Metal Hydride based on the mAH rating, but don't mix these with NiCads or charge them in the wrong type of charger.
The chemistries are different.
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Post by Ripper on Jan 27, 2007 0:45:54 GMT -5
Thanks guys!... The batteries are both Ni MH As I said, one set is Panasonic, the other is Energizer. Im using the charger that came with the Panasonic batteries and since they were Ni MH..I figure the charger is okay to charge the new Energizers.
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Post by johan on Feb 20, 2007 5:24:33 GMT -5
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Post by ChrisK on Feb 20, 2007 19:06:53 GMT -5
Yes, until you have a problem.
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Post by sumgai on Feb 20, 2007 19:33:29 GMT -5
did you know you can recharge alkaline batteries without any problem? Yes, until you have a problem.Which may be way sooner than you think...... sumgai
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Post by ChrisK on Feb 20, 2007 19:36:52 GMT -5
If there weren't any issues with recharging alkaline batteries, they'd be sold as rechargeable batteries.
Liability IS.
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Post by johan on Feb 21, 2007 12:07:28 GMT -5
If there weren't any issues with recharging alkaline batteries, they'd be sold as rechargeable batteries. This is what they call reverse logic. Don't believe them. 'if it's low voltage,...' I've a bag of 15 9V batteries I got from a wahwah freak (all 7.2V - 8.5V) that are now all around 9.5V like new. One I deliberately overcharged. The bottom started to lift off because on of the smaller batteries inside had popped, but no liquid or acid or stench, just looked a bit like hard grey clay. not really very lifethreatening. consumer's choice of course. I gladly be liable for saving 6 EUR/ battery ;D
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Post by ChrisK on Feb 21, 2007 18:03:00 GMT -5
Nope, just reality/marketing logic. The differences between a primary cell and a secondary cell result in the designation of a primary cell and a secondary cell.
One can also hammer nails with a thick glass bottle, but.............
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Post by johan on Feb 24, 2007 5:00:30 GMT -5
The differences between a primary cell and a secondary cell result in the designation of a primary cell and a secondary cell. One can also hammer nails with a thick glass bottle, but............. Dude, you're in a loop. Reverse logic: it's true because someone said it, if it wouldn't be true why would somebody say it? Of course the difference between an apple and a pear result in the designation of the former as 'apple' and the latter as 'pear'. Of course they don't guarantee them to be rechargeable as such. Another point: I haven't seen any battery that said "Do not recharge, might explode or leak acid". They say "Do not recharge. (full stop) Do not throw in fire, might explode or leak acid". It's really sad that you started putting down this true diy spirited experiment without a real argument other than that printed on the battery. Did you read the page? Experiment.
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Post by sumgai on Feb 24, 2007 16:31:10 GMT -5
johan, It comes as a matter of moral responsibility. You can indeed verify that Chris Kikta is a registered engineer. Persuant to that fact, he is charged, by the State in which he lives, to not give erroneous advice, and to offset any such erroneous advice where he finds it (and where practicible). At least, that's how it's worded on my documents, I'll bet his are roughly the same. Now, it's not so much a matter of peeing in someone's Cheerios, it's more a matter of interpreting words written on a product manufactured by a company that sells it's products to a the public. I'm sure you'll recall that nearly everything made today comes with warnings about how to use a product properly, or what not to do with the product, etc. Those warnings are the direct results of weasels lawyers gumming up the works by making money from other people's stupidity. The real reason the statement "Do not recharge." is printed on the battery casing is that if you do so, and if it causes you any harm, it is sure as shootin' that a lawyer will offer to take your case, and proceed to sue the manufacturer into oblivion. By publishing the warning, and moreover, by giving the broadest interpretation (no limits or reasons why, just don't do it, period), they are attempting to protect themselves. The theory stands so far, in most courts, that if you are intelligent enough to be able to earn the money to buy a product, you are likely to be educated well enough to be able to read simple statements. Further, if you can read those statements, you can probably understand that they are warnings, and that you would be well advised to heed them. Failure to do so is upon your head, so to speak. Now, we all know of outlandish court cases that seem to buck that trend. But the fact is, those are the ones that make the splashy media..... the vast majority of attempted cases don't make it into the media - they lost, for one reason or another. But in honor of who started this discussion (about what not to do), I'd like to paraphrase Chris like so: Stupidity is.And my commentary to that would be: Tort lawyers exist solely for the purpose of cancelling that statement. No, Chris isn't telling you that you're a fool for experimenting, he's telling you that there's a time and a place for nearly everything, and ignoring the lawyer-sponsered warnings on things electrical is not one of those places where you can experiment. That's his social responsibility speaking, not his fun-killing self. HTH sumgai
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Post by johan on Feb 25, 2007 7:35:21 GMT -5
johan, It comes as a matter of moral responsibility. You can indeed verify that Chris Kikta is a registered engineer. Persuant to that fact, he is charged, by the State in which he lives, to not give erroneous advice, and to offset any such erroneous advice where he finds it (and where practicible). At least, that's how it's worded on my documents, I'll bet his are roughly the same. I never saw administrators of a board draw discussion so much off topic. I believe Chris Kikta is a registered engineer but your discourse still strangely diverts from MORALITY to FINANCIAL COMPENSATIONS. It's our moral duty to tell you that if you do that and you burn your face, no way a sueing the company. I would think it a duty of the engineer to explain why it would work or maybe not work on a scientific level, ... " Stupidity is.And my commentary to that would be: Tort lawyers exist solely for the purpose of cancelling that statement." ...intelligent level. Intellegible level. "No, Chris isn't telling you that you're a fool for experimenting, he's telling you that there's a time and a place for nearly everything," [/quote] You also void your strat's warranty by rewiring! Don't see anybody freak on that. If the internet isn't the time and place to exchange valuable ideas like this, I don't know what it is becoming. Another vehicle of the corporate Babylon? Seems so,.... Nobody is more than anybody else on public internet boards. Nobody can be held responsible for anybody else stupity. Don't be affraid. If you are, get some alias. (if you are smart). If I would be an EE, and I would be hanging around here I would ask myself serious questions, cause I would be able to cook up my own wiring scheme like that. Maybe for experiments? guess not now, then what personal need is that? johan
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Post by sumgai on Feb 25, 2007 19:35:36 GMT -5
johan, I really don't know where you live, nor should it matter...... But I know for a fact that in America, at least, no Engineer is granted a license, in any state, to practice his craft without his first signing an affidavit that he promises to obey all the laws, rules, regulations, etc., written by that state. It just so happens that every state in the USA also has on the books, several laws that deal with moral, ethical, and social responsibility, particularly pertaining to those professionals who are licensed by the state. (Yes Major Major, it is[/] indeed a Catch-22.)
Engineers are not 'required' to explain anything, scientific or otherwise. But they are required to intercede when they perceive a need for preventative action. That action may be on a personal basis (great way to describe interactions that occur via the internet), or on a more public basis. In essence, your example of a Strat and its warranty is not appropriate - that's dealing with a product and a manufacturer's promise, not a safety issue.
And there it is, the real reason why Chris spoke up (and I too, after my fashion). Safety is of paramount concern to all of us, but when a professional takes a state-issued license, he or she is mandated to consider the safety of all those around him/her, not just his/her own self. I can't stress the clearly enough - there is no "gee, maybe if I keep quiet, the idiot won't blow himself up" - an observing Engineer is bound, by law, to speak up. (However, having spoken up, he is not bound to act like a policeman. He needn't "turn you in", he needn't take physical action to prevent your intended stupidity, etc.)
That's all that really happened here. We are simply stating that if you ignore the warnings, and if you adhere to the writings of a website that insists that the warnings are a bunch of crap, then you may not get the expected results. Indeed, you may harm yourself in a serious way. If you still go ahead and do it, fine, so be it. No longer my problem, nor Chris's either, if I'm not mistaken.
Well, here we are, at the bottom line. First, don't kid yourself that anonymity on a forum or board will automatically protect you from litigation or prosecution. If 'they' want you badly enough, you will become known to them, simple as that.
But more to the point, it would be nice if no one here started spreading rumors that GuitarNuts2 is a website where they ignore safety concerns, and act like the don't care what happens to their readers. We don't need that kind of reputation, I'm sure you'll agree. In short, if we, the GuitarNuts, never start down that road, then we won't have to backtrack, make excuses, ever apologize to anyone, or anything else that might give us a black eye.
However, you also said "don't be afraid to experiment". I agree! But unless you can deliver a solid refutation of some safety factor, then it is not wise to advise people to ignore the same, all in the name of experimentation. If you have an idea, and you can make it work, beautiful! I'm happy for you! But if others may come to harm because they don't have your expertise, and the process may be dangerous to them, should you be relieved of all responsibility, just because you're on the internet? Not on this forum you won't.1
And finally, alias and smart don't necessarily coincide - what was your point, please?
johan, you do contribute much to this forum, and your recent descriptions of how we might improve this place show that you know how think, that you are creative, and that you can articulate your ideas. I hope that you don't take any of this personally!
And for the record, I Am Not A Lawyer, so money doesn't enter into the equation, OK? ;D
Thanks.
Sumgai
1. Actually, any request for a member's ID is out of our hands. ProBoards will receive any such request (they are the final domain owner of record), and they won't even ask the Administrator, they'll simply look at the database themselves, then comply with the request for that ID.
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Post by dunkelfalke on Feb 26, 2007 4:36:50 GMT -5
no way
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Post by JohnH on Feb 26, 2007 5:52:02 GMT -5
Some important issues here. I am also an Engineer, if not an EE. My field is Structural Engineering, and the Institutions to which I belong would expect me to apply a 'duty of care' if I come across unsafe practices, even if I am not directly involved. For example, if I was to see obviously unsafe working at heights on a site across the street, I would report it to the organisation that polices site safety, and also the manager of that site.
Back to these batteries!
The chemistry of an alkaline battery may well be such that, in principle, it can be at least partly recharged. I can believe that web site, when the guy says he has done it and it worked, but;
It took all day to charge it.
When he overcharged one, it went fizz. Who is to say that another battery might not have gone pop? or bang? or BANG!?
He tried it twice. How many more times would it have worked? NiHh batteries degrade gradually, but over several hundred uses. How many cycles would a recharged alkaline work over - maybe just a few? - probably getting less effective after each one - we don't know.
NiMh batteries are pretty cheap these days, only a 3-4 times more than the cost of Alkaline batteries, and easy to replace after a long life of use.
Theres no point in recharging alkalines. Even if you could do it say 10 times, it would still be cheaper to use NiMh on a $/charge basis, and it risks at least some safety issues, not least to expensive equipment into which even a drop of mild battery stomach contents could spell ruin. Charging them still takes several hours at least, so no time saving.
So if I want rechargeables, I'll buy them, and use alkalines for good value disposable power.
John
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Post by dunkelfalke on Feb 26, 2007 9:16:10 GMT -5
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avoriaz
Apprentice Shielder
Posts: 31
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Post by avoriaz on Feb 28, 2007 21:25:58 GMT -5
Here in England it is possible to buy chargers designed to recharge ordinary alkaline batteries. I have had one for about 10 years and they do work quite well though you do not get anywhere near the number of recharges possible with Ni-Mh or Ni-Cd batteries. Four or five recharges is about average. They use a pulse charge method and constantly monitor the battery to prevent overcharging and the risk of leakage, bursting or worse. There are downsides to it. To get the best from a battery you are advised not to discharge it too much before recharging. If you let it run down to near zero it often will not take a charge at all. It is best to recharge them after about half the capacity has been used. This means a lot of battery swapping. Another downside I have discovered is that after a few recharge cycles the battery is more inclined to corrode and leak so you have to be careful. Frankly, although they do work quite well, I would not buy another if and when mine dies. I would just use Ni-Mh batteries. Here is a link to one such device. www.expertverdict.com/ProductDetails.aspx?language=en-GB&product=1015581&cat=ElecEnvironmentalTechnologyRechargeable alkaline batteries are also available here though they require a dedicated charger and are relatively expensive. They have not yet caught on in a big way but might do in time.
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