Rechargeable Cell Size Standards -was- Actual Size of 4/3 A NIMH Cells With Tabs Length Dimension

Methinks you protest too much. What is it about your application that can't tolerate a battery being .2% too short?

Ever measured the value of a resistor? How about the diameter of a bolt. Or the amount of coffee in a tin.

Funny story. Back in the old days when a tin of tuna was marked 6oz., I drained the water and weighed the net weight. Then I bitched at ChickenOfTheSea. They gave me the runaround, but once they decided that I was willing to hold as long as it takes, the came back with the admission that there was typically 3.5oz. of tuna in the can. And they saw no problem with that.

Hey, it's OK to say you don't know (but it's not required).

What I asked is if there are any size standards, and where they might be.. because I can't find 'em.

Like I mentioned, this was referring to not being able to find accurate, published (available to anyone, even you) lengths of common cells.

The reason for asking was to try to determine if there is a shorter version of the high capacity cells available.

The arrangement of the 12 cells in the pack is 3 "sticks" (end-to-end) of 4 cells each. The difference it makes is that the 4/3A cells I bought are longer, not shorter, and I don't need a precision caliper to see the sticks are ~1/4" longer. Is that the .2% you were harping about?

The difference is not modifying a ruggedized military grade xenon arc lamp if I can discover that there may be a cell size available, that I don't know about.

You're free to price a 22-1002 NIMH battery pack at Xenonics or military supply source to see if it might be more economical to rebuild packs with fresh, high capacity cells.

I didn't have the used battery pack to examine earlier because I couldn't find any new or used ones that were reasonably priced.. I half expected there to be some consistency in cell sizes.

-- Cheers, WB .............

Almost all battery powered devices has springs in the battery holders. Why do you think the springs are for?

I thing you are hunting ghosts.

Ok, so what if you found a single standard that was all encompassing. How does that help you buy cells? You're still gonna get whatever they send you. And high capacity cells tend to push the envelope...pun intended. Also, high capacity cells sometimes don't work so well in high drain applications. I put some computer grade 18650's in an electric screwdriver. Performance sucked. I guess there's a reason why it came with cells rated at half the capacity for high-drain applications.

What did they say when you called a major battery supplier or two or three?

No, those were your numbers closer to 66.11mm in length (not 66.25 mentioned previously).

I feel your pain, but I still don't think a standard will help you at all, unless you buy from the same place as the original.

And the length of the "stick" may include some interconnect between the cells.

A cells will be shorter.

That's a reasonable half-expectation.

I can tell you that I've rebuilt a few computer battery packs with

18650's and the space was always smaller than the batteries.

I'm thinking of a quantity of less than 1.. which maybe equals the number of times you've rebuilt a battery pack.

Battery pack.. hard plastic case with cells in it.

Battery pack, not a compartment for common retail store batteries.. ruggedized military grade light.

-- Cheers, WB .............

Only one manufacturer, Panasonic, showed any accurate specs for the sizes of their cells, but didn't list the 4/3A size cells.

Those numbers under the Diameter and Length headings show the size +/- size tolerances that can be expected.

And this is why I don't usually call manufacturers and vendors.. because I expect I'll need to keep repeating myself until it's time for them to go home.

The difference in size I mentioned was the cells I bought are 66.11mm, and the cells that were in the used battery pack are 63.4mm. I didn't have the used pack when I contacted a battery vendor, which I needed to explain twice, so I bought some cells based upon the measurement he sent me, and they were actually a little shorter than the measurement he specified.

The reason for my inquiry was that I might discover (learn for myself) a cell size that I don't know about.. which would be about 63mm long.

Significantly shorter cells' capacities are limited to ~2000mAh, not the

4100mAh of the OEM cells. Quality equipment designers want to know the precise size and weights of various parts to be considered for their new designs.

The tone of my initial post today was my usual sarcasm, as I'm not taking this seriously enough to lose sleep over, however, I have been expecting to be able to find a source for cell sizes. Lots of hours of looking online, and not much real data.

With the multitude of portable devices past and present, I woulda guessed that there would be more listings of sizes and size comparisons than 1 Wikipedia page and a Panasonic data sheet from 2005.

Premium quality battery manufacturers (mostly just Japanese brands) have several grades/series of rechargeable cells specifically intended for particular applications.. Mp3 player or industrial tool, for example. Maybe 5 grades of each different chemistry.

I suppose you coulda guessed that computer and power screwdriver power demands are not the same.

-- Cheers, WB .............

The following is not meant sarcastically or personally.

In trying to adapt CR123A lithium cells to a Polaroid 360 designed for PX-24 alkaline batteries, I had to insert several brass washers to make up the difference in length. Differences of a fraction of a millimeter don't seem important.

My experience with Chinese batteries is that the manufacturers don't care about the exact dimensions. The batteries are sometimes too fat to fit.

I did quite a bit of reasearching without finding much data for rechargeable cells. The cells I bought from TNR Batteries are FDK America brand, made in Japan (not just the lowest price I could find on Shenzhen/eBag).

I've modified circuit boards and battery compartments in plastic housings before, not a big deal with a Dremel/rotary tool. And when it's an older device, newer cells generally have more capacity in smaller cells, so it works out easily.

When I'm making up new battery packs I don't have any trouble with exact sizes because they don't have to fit in an existing hard plastic space. I use plastic sheet stock on the sides and shrink thick skins on them, because they can go into belt pouches.

I've only noticed one other instance where a little extra NIMH battery length made it a little more difficult to insert/remove AA NIMH cells in a charger.. yeah, they were from a discount store, off brand.

There will obviously be variations in dimensions of any particular size of cell, and even some China manufacturers specify size tolerances for their cells (Tenergy).

The issue I brought up was that there doesn't seem to be any concise listings of different cell sizes, not their exact dimensions and tolerances.

For almost all *letter* sizes of rechargeables, there are generally several sub-sizes.

We've never seen more portable devices than there are presently. It's a bit curious that battery size comparisons and datasheets/information seem to be so obscure.

--
Cheers, 
WB 
............. 


"William Sommerwerck"  wrote in message  
news:klta65$oj3$1@dont-email.me... 
> The following is not meant sarcastically or personally. 
> 
> In trying to adapt CR123A lithium cells to a Polaroid 360 designed for  
> PX-24 alkaline batteries, I had to insert several brass washers to make up  
> the difference in length. Differences of a fraction of a millimeter don't  
> seem important. 
> 
> My experience with Chinese batteries is that the manufacturers don't care  
> about the exact dimensions. The batteries are sometimes too fat to fit.

"tuinkabouter"

** To apply pressure to the electrical contacts ** Rechargeable cells that are intended to be manufactured into custom packs are made in a great many sizes and there is little benefit ( for the makers) in exact standardisation.

So they don't pay it much attention.

And no-one but a fool would attempt to catalogue it all.

.... Phil

mike formulerede spørgsmålet:

Andy Rooney in his 60-minutes essays once talked about everything getting smaller, like paper towls, cans of washingpowder or food etc.

But ended with admitting they were not better themselves: 60 minutes only was about 45 minutes of programming, the rest commercials :-)

Leif

--
Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske  
beslutning at undlade det.

After numerous additional more hours of searching, all I was able to find out was that NEDA cooperates in the "standardization of names" for components such as batteries.

The IEC is an organization "dealing with" electrical, electronic and related technologies. This publication is specifies marking, designation, dimensions, tests and requirements for portable sealed nickel-metal hydride.

The IEC publication 61951-2 second edition 2003-2004 includes NIMH cells in Part II. The report covers letter designations related to grades of performance, temperature capabilities, recharging rate capibilities and discharging endurance. These letters are not the AA, AAA, C, D etc assigned to different sizes, but instead classification letter prefixes or suffixes.

The 4/3A cells aren't even shown, although the (several) other sizes of A cells are, but the pub is already a decade old. The IEC reports/publications don't appear to be easily accessible for non-members.. oic, the pubs are for sale, same as BSI pubs.

It's not likely that any manufacturers are required to comply with standards, although some companies traditionally have, as it makes product procurement easier.. like mil-specs designate numerous characteristics of parts and materials.. when the particular mil-spec is looked up, there are all the characteristics.

Stated in the Energizer compliance statement "All Energizer and Eveready products are designed to meet or exceed the requirements of the various national and international industry battery standards.

Then they list reference publications for various organizations' standards including IEC, NEMA, ANSI, ASTM and JIS, indicating their products' compliance with industry standards.

NEMA/ANSI C18.2 pub's purpose is: to ensure the electrical and physical interchangeability of products from different manufacturers.. and also to provide guidance to consumers, manufacturers, designers and other end users.

Funny thing is, the pub doesn't include where the info can be found.. just rest assured that they spent a lot of effort compiling the data, even though they might be the only people to have ever seen it.

After all this time it occurred to me that one of the internal safety components in the military cells may have been ommitted so the cells could be shorter, because the military doesn't risk/face damage or injury litigation the way battery manufacturers do with consumer end users.

I think my quest is concluded.. if 18x63 or 64mm long 4/3A cells exist, no one is interested in selling them.

--
Cheers, 
WB 
............. 

"Wild_Bill"  wrote in message  
news:G67gt.184388$6r1.42381@en-nntp-07.dc1.easynews.com... 

>I get dizzy roaming around from one supplier/manufacturer to another  
>looking for any standards as they apply to differently sized cells. 
>