On 5/1/2013 1:23 PM, Wild_Bill wrote:
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.

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?

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?

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

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 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.

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.
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.

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


"mike" wrote in message
...
On 5/1/2013 4:35 AM, Wild_Bill wrote:
I get dizzy roaming around from one supplier/manufacturer to another
looking for any standards as they apply to differently sized cells.

Where do the 18650, 17670 and (fractional) A sizes come from? EIA now
known as ECIA, IP&E, iNEMI?
Probably not EIA/ECIA http://en.wikipedia.org/wiki/EIA_standards
IEC, maybe.
I've looked at the consumer battery size charts (wiki etc) and haven't
seen anything that's even close to being concise.

Great Googly Moogly.

Update:
I bought some used OEM battery packs and upon opening one, found the
length of the cells to be about 63mm (63.4 x 18mm dia). The skins are
marked NT410LAH, but the actual metal shell is marked H410LAH-C under
the skin (also 1K05F likely a date/production number).
These cells are stated to be 4100mAh NIMH. Coincidently, GC brand has a
GC410LAH cell.

Previously posted in Feb, I was inquiring about cell lengths.
Excerpt:
I received my order of 4/3 A NIMH 4500mAh cells (with tabs) and they
measure
closer to 66.11mm in length (not 66.25 mentioned previously).

Apparently, it's another issue of non-standardized "standards".

Specs for 18650 flat top cells show 65.5 x 18mm.
Most sellers show flat top 4/3A cells as over 65 x 17mm
Specs for 17670 flat top cells show 66/67 x 17.5mm

As a point of levity, an Amazon seller shows 4/3A flat top cells to be:
Width: 0.66" Height: 2.61" Diameter: 0.69"

I saw a mention of a 7/5A cell size.. really? Can't come up with another
letter?
So maybe the OEM cells in this instance are 14/12A.

Panasonic OEM/industrial chart shows "18670 (L-Fat-A)" cells.. but no
4/3A size.

Dizzy I tellya.

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