Capacity of various Duracell AA cells?

|It's hard work untangling Duracell's pruct range and the relative |performance. | |I don't think Duracell are great value but they can be got anywhere |and I want to know the relative merits of their popular alkaline |batteries. | |--------- | |What is the rated capacity in mAh of an alkaline Duracell AA cell in |the following product ranges which I recall from (perhaps faulty?) |memory: | | Duracell (ordinary) | Duracell Plus | Duracell M3 | |--------- | |The Duracell web site has a technical page but it refers only to: | (1) Ultra Digital | (2) Coppertop |

|yours confused

Confusion is Duracell's marketing ploy which you have fallen for :-(

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.

NiMh batteries are sold by Ampere Hour Capacity, why not Alkalines.

each

They can't, there is no one figure. Capacity of alkaline cells varies depending on the load exerted on them. The relationship between current drawn and useful voltage delivered is not linear. However, the specs are available:

-- Mike W

One place I work at spends many thousands a year on alkaline cells for radio mics, etc.

Duracell *Procell* seems to be consistently the best value when bought in bulk. Shops will often charge up to four times the price of a Procell for a gold top but they certainly don't last appreciably longer.

Thing to be vary of is cells sold at car boot sales, etc. They may be forgeries or well past their sell by date. And often poor value.

Anyone any thoughts on Energisers? I bought a load to use when cooped up in a hospital room, and I used them so heavily I lost track of how long they lasted.

But CPC have a good offer on them right now...

|> |It's hard work untangling Duracell's pruct range and the relative |> |performance. |> | |> |I don't think Duracell are great value but they can be got anywhere |> |and I want to know the relative merits of their popular alkaline |> |batteries. |> | |> |--------- |> | |> |What is the rated capacity in mAh of an alkaline Duracell AA cell in |> |the following product ranges which I recall from (perhaps faulty?) |> |memory: |> | |> | Duracell (ordinary) |> | Duracell Plus |> | Duracell M3 |> | |> |--------- |> | |> |The Duracell web site has a technical page but it refers only to: |> | (1) Ultra Digital |> | (2) Coppertop |> |

|> |yours confused |>

|> Confusion is Duracell's marketing ploy which you have fallen for :-( |>

|> 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. | |They can't, there is no one figure. |Capacity of alkaline cells varies depending on the load exerted on them. |The relationship between current drawn and useful voltage delivered is not |linear. However, the specs are available: | |

Just a marketing excuse. It would be a simple matter to give a single figure based on a single load ?cycle? and a single voltage endpoint. That would give enough information even for someone like me who understands the real specs were I to put my mind to it.

In message , "Dave Plowman (News)" writes

So how do GP super Alkaline compare ?

I buy them in boxes of 40 from CPC

more megawatt hours / buck IMHO

AmpHour (or WattHour) is not really a constant number. And sometimes it isn't even very important. For example, the common CR watch cell batteries have impressive milliwatt hour ratings, but only at instantaneous current loads below 100 microamps. So if you try to draw a milliamp, you won't see anything like the rated capacity.

The message from Dave Fawthrop contains these words:

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.

I suspect having two figures, C1 and C10 rates, for example, might be a way round it but there's pleny who'll say it's too confusing.

But doesn't the Ah rate of nicads vary in the same way?

Owain

The message from Owain contains these words:

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.

each

No, it is virtually constant.

-- Mike W

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

The message from Tim S contains these words:

Yeah, useless bunch that test the obvious but ignore the interesting aspects of things.

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

Yup I used to do that as well...

However I found they are very poor in comparison. They will run my Psion

Having said that they are plenty good enough for low drain long shelf life applications like remote controls, clocks etc.

|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.

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

Hmmm! I'd of thought a company that uses batteries on a daily basis would go in for rechargables?

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