P3D Re: Ni-Cad batteries

[michaelk@xxxxxxxxxxxxxxxxxx (Michael Kersenbrock)]

> > Their voltage is pretty much
> > constant until it nose-dives right at the very end.  Unlike
> > Alkalines.
> > 
> > Mike K.
> 
> You missed the point completely! Each CAMERA will determine if there
> is enough room. I have yet to find a point and shoot that IS designed

Seems to me margin is just that.  Margin.  If the camera will work
with 2.2 Volts or greater, and 2.4 is provided, then it will work
just fine.  If you say that the camera itself needs 2.6 volts sometimes
to make up for some event, then you're right that it won't work -- but
you're not right that it'll work with 2.2 as previously stated.

Some cameras may not like the very low ESR, in particular their flash
charging circuit may depend upon inrush current being battery limited.

> for ni-cads. So if it is a two cell camera, it is designed around a
> 3.0 volt supply. To start with only 2.4 volts isn't enough when the
> camera (a Nikon) is inoperable at 2.2 volts. With the current involved
> during frame advance, dirty battery contacts alone would render the
> camera inoperable.

True, but hopefully the contacts aren't that dirty.  Even my old
P&S cameras have contacts that look like they're new. With NiCad's
low ESR, the voltage also won't drop within the battery like 
it would with Alkalines.  NiCad ESR is *MUCH* lower than Alkaline's.
The difference in a flash unit (recharge time) is sometimes dramatic.

I've used NiCad's in a couple P&S's that say not to use
NiCad's, and they've worked fine as far as I could see.  :-)

Yes, I've been naughty.  

Mike K.


P.S. - Devices designed for Alkalines usually are designed for
       operation with a voltage down to less than 1-volt per
       cell.  Else the battery life of the Alkalines will be
       quite short.  :-(  Certainly one advantage of Realists
       (etc) -- the non-existant battery lasts "forever".  :-)




  


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