Re: Camera zaps NiMH batteries

On Sun, 27 May 2007 02:09:08 -0500, BaumBadier wrote:

Therein lies your problem, Alkalines and NiMHs are not the same voltage.
Alkalines run about 1.6v per cell when fresh, NiMHs up to about 1.25-1.3v per
cell when freshly charged. Your camera is probably detecting the slightly lower
voltage of the NiMHs and shutting down.

We don't yet know enough to conclude what the problem is. It's
true that alkaline batteries start at a higher voltage than NiMH,
but all of the cameras I'm aware of will not shut down until the
NiMH batteries are exhausted, which is *very* close to the 1.0 volt
level per cell. Under the load imposed by cameras, even fresh
alkalines will probably drop to below the 1.5v level very quickly.


Since it appears your camera wants a higher voltage,

We don't yet know that this is true. I have a hunch that a new
set of NiMH batteries would greatly outlast fresh alkalines.


you might do better with disposable Li-Ion AA cells. But be aware
their top voltage when fresh can be as high as 1.9v per cell.

Wrong on two counts. Li-Ion cells are rechargeable cells and they
*are not* made into AA cells, since they would be over 3 volts per
cell. Lithium batteries (Lithium/Iron Disulfide (Li/FeS2)), such as
the Energizer L91 AA cells don't provide voltages that high when
fresh except possibly under zero load. According to Energizer's
data sheets, under loads significantly lower than that required by
cameras, they provide as much as 1.5 volts to the camera only when
fresh out of the package. The data *** shows that they can
provide 1.6 volts when fresh, but the example they give for this is
a 100mW load that's so light that the batteries can provide that
power for just about 45 hours.


Some people run them for a few minutes in a pen-light to cut off the
peak charge before using them in digital cameras to be safe.

That can't hurt, other than to waste some of the power, but it's
not likely to help. On the other hand, some cameras should *not*
use lithium AA batteries at all, depending on how they were
designed. Several models from different manufacturers specifically
warn that lithium AA batteries should not be used.

Examples:
Kodak's manuals for the C300, C533, C643 and C663 indicate that
lithium AA batteries can be used. But owners of other Kodak models
have said that their manuals warned to avoid using lithium
batteries.

Sony's manual for the DSC-H1 recommends that NiMH batteries should
be used, and adds :

:> Batteries you cannot use with your camera
:> Alkaline batteries
: Manganese batteries
:> Lithium batteries
:> Ni-Cd batteries


But they have an amazing shelf life so there is virtually no charge lost
between infrequent uses of your camera, even when setting for years.

Very true. Energizer's L1 AA cells retain 90% of their rated
capacity after sitting unused for 15 years at 21º C. Their E91 and
X91 alkaline AA cells retain 80% of capacity after 7 years at 21º C.

While you can't expect standard NiMH batteries to provide any
power if they sit unused for a year or two, the new NiMH batteries,
such as Sanyo's Eneloops and RayOVac's Hybrids can sit unused for
more than a year and will still retain a good percentage of their
power.

.

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