£10 for twelve 1800 mAh NiMH AA cells from Maplins - bargain?

[Zak]

On Mon 23 May 2005 16:34:49, Quaoar wrote:

I don't have a micrometer to do the measurements, but the
Panasonic 2300mah AAs that I purchased recently are perhaps a
fraction of a millimeter too large diameter and consequently
difficult to fit into the molded slots in a charger but
especially in several scanner radios and a logitech cordless
mouse. Trimming the label jackets helps, but they are still a
very tight fit. There is no question that the diameter is
greater than any 1800mah AA cells I have.

I think also that sometimes the cell has a flatter button to
deliberately make it harder to go into consumer products.

 

[Dr Teeth]

There is no question that the diameter is
greater than any 1800mah AA cells I have.

The contacts are at the *end* so *length* counts, not diameter.

--
Cheers,

Guy

** Stress - the condition brought about by having to
** resist the temptation to beat the living daylights
** out of someone who richly deserves it.

 

[Gama Chameleon]

The contacts are at the *end* so *length* counts, not diameter.

*snort*. So how does it fit in the battery compartment if its too
wide?

 

[kony]

The contacts are at the *end* so *length* counts, not diameter.

Sometimes that is true but not others. A battery
compartment can be wide enough for the cells but at the end
where the contact is it may be molded to taper (sort-of
notched) to better align the contacts in the center.

That can result in the battery fitting in the compartment
but the slightly larger cell diameter causes the negative
end to sit further back, compressing the spring more than
usual while the positive button end doesn't touch the
(typically) non-sprung flat contact. In other words,
because one end has the spring it sits further down in the
compartment. While this is rarer, it is possible.

 

[Colin Reddish]

I don't have a micrometer to do the measurements, but the Panasonic
2300mah AAs that I purchased recently are perhaps a fraction of a
millimeter too large diameter and consequently difficult to fit into the
molded slots in a charger but especially in several scanner radios and a
logitech cordless mouse. Trimming the label jackets helps, but they are
still a very tight fit. There is no question that the diameter is
greater than any 1800mah AA cells I have.

That is not my experience. I have just measured (with a micrometer) the
diameter of a variety of cells I have and there is no significant difference
between any of them. The range of diameters between individual points on the
same cell and between different capacity cells (1300, 1800 and 2300 NiMH and
also some NiCd AA cells) and different manufacturers (Uniross, Vanson, Hama
and GP) was 14.00 to 14.30 mm. There was no correlation between the average
diameter and cell capacity, type or manufacturer.

 

[kony]

That is not my experience. I have just measured (with a micrometer) the
diameter of a variety of cells I have and there is no significant difference
between any of them. The range of diameters between individual points on the
same cell and between different capacity cells (1300, 1800 and 2300 NiMH and
also some NiCd AA cells) and different manufacturers (Uniross, Vanson, Hama
and GP) was 14.00 to 14.30 mm. There was no correlation between the average
diameter and cell capacity, type or manufacturer.

It may be that there are some "true" 2300mAh cells that
aren't the larger diameter but one has to be careful when
considering off-brand generics, as their labeled capacity
can tend to be a little optimisic, if not an outright lie
based on different testing methodology.

The Panasonic (sanyo) cells are among the best in the
industry, I doubt many (if any) manufacturers make cells
with higher true capacity in a smaller volume unless they're
using another construction that has other limitations (like
higher internal resistance, lower current potential).