Capacity of various Duracell AA cells?

Guy King wrote:


But doesn't the Ah rate of nicads vary in the same way?
Owain
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Yes, but the NiMh market has gone the way of revealing it (though not always with great accuracy). If a couple of primary cell makers would start printing the figures on their cells it wouldn't be long before the others followed.
IIRC there is a "gentlemen's agreement[1]" between Ever Ready and Duracell over marketing the very highest capacity cells in Europe.
[1] qv Consumer ripping-off system.
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each
No, it is virtually constant.
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Primary cell makers do disclose capacities. Just not for alkaline or zinc carbon it seems. Lithium primary cells, which aren't that exotic these days, often have capacity information available.
Tim
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Yeah, useless bunch that test the obvious but ignore the interesting aspects of things.
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They don't set out to be a specialist mag. They are there to give guidance to those who don't really care much about reading in depth reviews. And most camera mags etc use jargon those just looking for say a holiday camera won't understand.
Surprised no-one commented on their router test a couple of months ago.
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Tim Auton wrote:

I've found good data on most common alkaline cells at the manufacturers' web sites. They typically show discharge capacity or voltage vs time for a variety of common discharge regimens.
Roy Lewallen
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Guy King wrote:

Recharchable cells for public retail have always shown the AH, same as car batteries.
Otherwise we wouldn't know how long to charge them in the fixed curent chargers which was all that used to be available until recently.
john2
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wrote:
|Guy King wrote: |>>Until Alkaline battery manufacturers state the Ampere hour capacity on each |>>battery, I will believe that they are all the same and buy the cheapest |>>available. |> Their argument against doing this is that the effective Ah rate of each |> cell differs at different discharge rates and that comparing like with |> like wouldn't be possible. | |But doesn't the Ah rate of nicads vary in the same way?
The same thing happens with *all* batteries whatever the Chemistry.
NiMhs give a single figure, why not Alkalines?
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Dave Fawthrop wrote:

NiMh capacity varies only a relatively small amount over a very wide range of load conditions. By comparison, alkalines vary a whole lot. The amount you can get out of one depends heavily not only on the discharge rate, but how long the cell is allowed to rest in between partial discharges. Also, cells can be optimized for light or heavy discharge rates, so one which does better at low rates might do worse at high rates.
You can be sure that if manufacturers were pressed to come up with a single number for alkaline cell capacity, each would set up the test at the most favorable condition for their particular cell (and then inflate the result, like they all do for NiMh cells). The resulting numbers would be totally useless.
Take a look at the data sheets which are readily available at the manufacturers' web sites, and it won't take long to see what I mean.
Roy Lewallen
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|Dave Fawthrop wrote:
|> wrote: |> |> |Guy King wrote: |> |>>Until Alkaline battery manufacturers state the Ampere hour capacity on each |> |>>battery, I will believe that they are all the same and buy the cheapest |> |>>available. |> |> Their argument against doing this is that the effective Ah rate of each |> |> cell differs at different discharge rates and that comparing like with |> |> like wouldn't be possible. |> | |> |But doesn't the Ah rate of nicads vary in the same way? |> |> The same thing happens with *all* batteries whatever the Chemistry. |> |> NiMhs give a single figure, why not Alkalines? | |NiMh capacity varies only a relatively small amount over a very wide |range of load conditions. By comparison, alkalines vary a whole lot. The |amount you can get out of one depends heavily not only on the discharge |rate, but how long the cell is allowed to rest in between partial |discharges. Also, cells can be optimized for light or heavy discharge |rates, so one which does better at low rates might do worse at high rates. | |You can be sure that if manufacturers were pressed to come up with a |single number for alkaline cell capacity, each would set up the test at |the most favorable condition for their particular cell (and then inflate |the result, like they all do for NiMh cells). The resulting numbers |would be totally useless.
Not IMI totally useless, just limited. Better than the nothing which the average buyer, who would not understand the data sheets, has at the moment. Then an international standards body should set up the test method.
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on each

cheapest
each
with
rates.
moment.
I personally use aerocells, a brand name of lidl chain,german supermarket.They come for 3 euros a 8 cells, so I don't really mind if they last 1 year or 11 months 15 days in a quartz clock.
-- Tzortzakakis Dimitrios major in electrical engineering,freelance electrician 542nd mechanized infantry batallion dimtzort AT otenet DOT gr
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But limited to uselessness for most consumers. A single number won't tell you if a particular battery is better suited for years of life in a digital clock or more pictures in a digital camera. Batteries optimized for one scenario would be awful in the other.
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wrote:

Since the early seventies, probably earlier, there were two kinds of battery that a consumer would see for either a dry cell or an alkaline: Long Life, and High Power. So if you use a single value for capacity per battery type, and it is printed honstly on the appropriately named battery, people will know that this figure applies if they use the battery appropriately.
There are two points that could be confusing:
1. Mixing up the battery types. 2. Demands that are some way between both types.
There's not much you can do about the first, when people fail to understand the difference, telling them more data won't help, but telling them less is disrespectful.
The second case is the tougher one, and there the single value won't be enough, but you can refer people to a makers graph of lifetime for average current drawn per life, one graph per battery type (Both graphs printed on cardboard packaging for both types). They can put both plots together and make their own choice. The point where the plotted lines cross is the set of conditions for which both batteries are equal to the task. This idea is simple enough to grasp by intuition, and also highly informative if you look at the values for capacity and drawn current.
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On Mon, 08 May 2006 09:00:02 -0400, William P.N. Smith
|>|You can be sure that if manufacturers were pressed to come up with a |>|single number for alkaline cell capacity | |>|The resulting numbers |>|would be totally useless. |> |>Not IMI totally useless, just limited. | |But limited to uselessness for most consumers.
Who would not understand the Data sheets anyway.
|A single number won't |tell you if a particular battery is better suited for years of life in |a digital clock or more pictures in a digital camera. Batteries |optimized for one scenario would be awful in the other.
Already sussed that one. Alkalines for long life NiMh for power applications
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On Mon, 08 May 2006 09:00:02 -0400, William P.N. Smith

Absolutely. The zinc-air PP3's despite costing an arm and leg and theoretically offering a higher mAh than alkalines are useless for low current applications such as smoke alarms.
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The local fire brigade in association with the local council gave away loads of smoke alarms with "10 year" lithium PP3s fitted. About three years later the batteries are dying. This wouldn't matter except that there's a pop-rivetted retainer over the battery so you "can't" replace it.
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Dave Fawthrop wrote:

They are different. ISTR the Maplin catalogue used to give the capacities some years ago (before they switched to selling boys toys, etc).
MBQ
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snipped-for-privacy@hotmail.com wrote in

Nice summing up of what's happened to Maplin there. >:) It's a sad crime what's been done to that firm.
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I believe that some two years ago Practical Sailor magazine did an AA alkaline comparison test using hand held VHF transreceiver and Duracell Copper top came out best with Panasonic better than Eveready.
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