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Pentax Optio S50 Cut-off Voltage ???

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Anonymous
April 19, 2005 12:12:10 PM

Archived from groups: rec.photo.digital (More info?)

Last week I bought a Pentax Optio S50 with 128Mb card. It takes great
pictures, has an excellent menu system and is nice and compact.

However, it is completely unusable due to the ridiculously short life
it gives AA alkaline batteries. So far, I've used two pairs of
Duracells and the lithium(?) AA supplied by Pentax with the camera, to
take 22 pictures (plus 5 to 10 minutes of previewing pictures on the
screen).

A search on the internet shows that other people have found this to be
the case, both with this Pentax and others.

NiMH rechargeables seem to get a good name, but does anyone have any
direct experience using them with this model? Also, does anyone know
the cut-off voltage for this model. I am worried that it might be too
close to the 1.2V for fresh NiMH.

[The funny thing about all this is that the camera was chosen BECAUSE
it used normal AA sized batteries and not an internal battery. I
thought I could replace them with ease and not worry about carrying a
charger about with me. Of course, now I'm replacing them with a bit too
much ease!]


Thanks.
Anonymous
April 21, 2005 4:12:36 PM

Archived from groups: rec.photo.digital (More info?)

"LJMeek" <Lindsay.Meek@Jacobs.com> wrote in message
news:1113923530.111293.258630@f14g2000cwb.googlegroups.com...
....
> Last week I bought a Pentax Optio S50 with 128Mb card. It takes great
> pictures, has an excellent menu system and is nice and compact.
>
> However, it is completely unusable due to the ridiculously short life
> it gives AA alkaline batteries. So far, I've used two pairs of
> Duracells and the lithium(?) AA supplied by Pentax with the camera, to
> take 22 pictures (plus 5 to 10 minutes of previewing pictures on the
> screen).
....

You problem is endemic to pretty much every camera that uses AA sized
batteries. The real issue is the design of the battery. Alkaline batteries
are optimized for long shelf life (little to no self discharge) and high
capacity
(long run time). As with every engineering solution, there are tradeoffs.
Alkalines have a high internal resistance, so they have a fairly low
instantaneous current capability. In simple terms, they aren't terribly
good for devices that use short duration, high bursts of power (like digital
cameras). They are good for things that use steady, long term power
(like clocks, etc...). I believe that the chemistry actually depletes
around
the internal electrodes during momentary high discharge usage. This
causes the battery to look like it is exhausted. Actually, if you let the
battery rest for a while, it should once again function. Obviously, that's
less than ideal for camera use.

As an alternative, most cameras that can use alkaline AA batteries can
also use non-rechargeable Lithium-Ion AA batteries. These also have
a long shelf life, high capacity, and can deliver the instantaneous current
demanded by digital cameras. (Don't be fooled by various marketing
names like "titanium, etc...". Only real lithium-ion batteries will do.)
In my older Minolta S404, the "heavy duty" (read non-alkaline) AAs that
came with the camera couldn't even turn the camera on, but a pack of
Lithium-ion batteries works like a charm.

So, what's the draw back of non-rechargeable Lithium-ion? Cost. I doubt
that you will find them for less than $2.00 (American) each.

Your third alternative is NiMH rechargeable AA batteries. With a good
"fast charger" or a trickle charger (not a timed charger), you can get
hundreds, even thousands of uses from each battery. They are pretty
inexpensive, and work wonderfully in digital cameras. The downside
is shelf life. NiMH have a relatively high self-discharge rate, so they
do run down, even just sitting in a drawer. I have a two sets that I
use in my S404, and I try to remember to "top off" the batteries when
I know I'll be shooting the next day. I also keep a set of Lithium-ion
non-rechargeable for emergencies. My batteries are rated at 1850mAh,
but you can find new ones up to 2500mAh.

Some newer cameras are designed to use (apparently) smaller bursts
of current, and work much better with alkaline batteries. Also some
battery manufacturer's are developing alkaline batteries with lower
internal resistances that should work better in digital cameras.

Good luck,


--
Dan (Woj...) [dmaster](no space)[at](no space)[lucent](no space)[dot](no
space)[com]
===============================
"The sky turned to black / Would he ever come back?
They would climb a high dune / They would pray to the moon
But he'd never return / So the sisters would burn
As their eyes searched the land / With their cups full of sand"
Anonymous
April 22, 2005 8:29:32 AM

Archived from groups: rec.photo.digital (More info?)

Thanks for that.

Since my post, I've taken the plunge and bought 4 AA 2300mAh Uniross
NiMH with a 2-hour charger. I got them yesterday and determined to see
how long the batteries lasted. (I know this is a bit sad, but that's
science for you.) They were brilliant. For almost 4 hours *continuous*
use, I took flash photographs. I filled (and deleted) my 128Mb SD card
just over 3 times, leaving the LCD lit throughout. The camera then
reported a "depleted battery", but I can still preview.

The charger charges 2 or 4 at a time. Since you say they can run down
sitting in a drawer, is it better for their life to lie with a charge,
or without? The charger instructions have no guidance on this.

There's no zealot like a convert. I will never buy any standard size
alkaline batteries again, especially for kids toys, etc.

Thanks again.
Related resources
Anonymous
April 22, 2005 9:02:49 PM

Archived from groups: rec.photo.digital (More info?)

My 700 mAh NI-CD batteries don't last that long,but they are OK for me.I
also bought another set of 2 AA NICD batteries (5.60 euro) for my pocket
light which I use when I work and have to cut the power.The original Orbit
charger came with 4 NI-CD batteries and cost 11 euros.

--
Tzortzakakis Dimitrios
major in electrical engineering, freelance electrician
FH von Iraklion-Kreta, freiberuflicher Elektriker
dimtzort AT otenet DOT gr
? "LJMeek" <Lindsay.Meek@Jacobs.com> ?????? ??? ??????
news:1114169372.278788.229340@f14g2000cwb.googlegroups.com...
>
> Thanks for that.
>
> Since my post, I've taken the plunge and bought 4 AA 2300mAh Uniross
> NiMH with a 2-hour charger. I got them yesterday and determined to see
> how long the batteries lasted. (I know this is a bit sad, but that's
> science for you.) They were brilliant. For almost 4 hours *continuous*
> use, I took flash photographs. I filled (and deleted) my 128Mb SD card
> just over 3 times, leaving the LCD lit throughout. The camera then
> reported a "depleted battery", but I can still preview.
>
> The charger charges 2 or 4 at a time. Since you say they can run down
> sitting in a drawer, is it better for their life to lie with a charge,
> or without? The charger instructions have no guidance on this.
>
> There's no zealot like a convert. I will never buy any standard size
> alkaline batteries again, especially for kids toys, etc.
>
> Thanks again.
>
Anonymous
April 25, 2005 7:49:26 PM

Archived from groups: rec.photo.digital (More info?)

"LJMeek" <Lindsay.Meek@Jacobs.com> wrote in message
news:1114169372.278788.229340@f14g2000cwb.googlegroups.com...
>
> Thanks for that.
>
> Since my post, I've taken the plunge and bought 4 AA 2300mAh Uniross
> NiMH with a 2-hour charger. I got them yesterday and determined to see
> how long the batteries lasted. (I know this is a bit sad, but that's
> science for you.) They were brilliant. For almost 4 hours *continuous*
> use, I took flash photographs. I filled (and deleted) my 128Mb SD card
> just over 3 times, leaving the LCD lit throughout. The camera then
> reported a "depleted battery", but I can still preview.

Just the right tool for the job. }:) 

>
> The charger charges 2 or 4 at a time. Since you say they can run down
> sitting in a drawer, is it better for their life to lie with a charge,
> or without? The charger instructions have no guidance on this.
....

I don't know the answer. I tend not to leave mine in the charger, based
on some recommendation or warning that came with either the charger
or the batteries. On the other hand, I've left them charging overnight
with no harm. A trickle type charger shouldn't cause a problem, and
any decent "fast" charger goes into trickle mode after the battery
charges, so I expect there would be no problem, unless the charger
somehow failed. Then you could wind up with a little overheat/fire
problem.

Other than that, I think NiMHs recommend storing when charged.


--
Dan (Woj...) [dmaster](no space)[at](no space)[lucent](no space)[dot](no
space)[com]
===============================
"The sky turned to black / Would he ever come back?
They would climb a high dune / They would pray to the moon
But he'd never return / So the sisters would burn
As their eyes searched the land / With their cups full of sand"
Anonymous
April 26, 2005 4:58:24 AM

Archived from groups: rec.photo.digital (More info?)

Cheers.
!