From: Ron Hunter on
ASAAR wrote:
> On Mon, 25 Jun 2007 16:09:51 -0700, SMS wrote:
>
>>> I also saw you point out some of the inaccuracies in this very thread ... and
>>> you are correct, mostly silence.
>> Sorry, he was filtered long ago. If he's changed his ways I need to go
>> clear him out of my filter to see what he's saying now.
>
> Sorry, but when I pointed out your inaccuracies and misstatements,
> well before you started using your filter, you never even attempted
> to disprove any of my corrections. You simply ignored them and
> continued spouting the same inaccurate facts. It's *you* that needs
> to change your ways, but I'll be quite surprised if you do. We can
> start with one of your repeated points of misinformation, that
> cameras don't or can't have battery meters for NiMH cells due to
> their supposedly flat discharge curve. There's plenty of evidence
> that that is untrue, and I could repeat some of the reasons for you
> if you're willing, but I'm amazed that a self-proclaimed "battery
> expert" wouldn't know this already.
>
Isn't a battery meter on a device using NiMH batteries rather like a
radar detector with such a short range that it only tells you you have
been caught? Given the discharge curve, it need only be a dot in the
LCD display that says your battery is below the cutoff voltage. Still,
my camera do have such a warning, and it really means what it says
because only a couple of pictures can be taken with that warning on
before ugly things start to happen.
From: SMS on
Ron Hunter wrote:

> I don't think you can blame the batter manufacturers for this. It is a
> matter of convenience (and cost) taken by the camera manufacturer. It
> is also probable that the AA batteries are removed more often that
> Li-Ion batteries, so this makes the problem worse. Still not a fault of
> the batteries.

It's a problem that is aggravated by the type of battery. More frequent
insertion and removal of the batteries, plus the way the batteries make
contact. On my D-SLR, they solve this problem with an AA battery tray
for the grip. This not only makes it much faster to swap batteries (you
can buy extra trays) but eliminates the issue of the battery door and
tabs. Of course a manufacturer could make battery packs with NiMH cells,
such as are used in many cordless phone handsets, and use a little
connector or other mechanical method of making contact, but this is
normally not done.

BTW, replacement battery doors for many cameras are available from
"http://www.digitalcamerapartsdepot.com/". However be sure that the
damage isn't flimsy plastic tabs inside the camera, rather than tabs on
the door itself. If the tabs that break are inside the camera, i.e. such
as the Canon A640, buy a roll of duct tape.
From: SMS on
Ron Hunter wrote:

> Isn't a battery meter on a device using NiMH batteries rather like a
> radar detector with such a short range that it only tells you you have
> been caught? Given the discharge curve, it need only be a dot in the
> LCD display that says your battery is below the cutoff voltage. Still,
> my camera do have such a warning, and it really means what it says
> because only a couple of pictures can be taken with that warning on
> before ugly things start to happen.

Yes, that's currently the case. It's too expensive for a manufacturer to
integrate a pulse-load type of battery tester into an AA powered camera,
especially since they couldn't charge extra for it since so few users
would understand that it's something that's worth an extra couple of
dollars.

It's more like the oil pressure light on a car. Rather than being
labeled "Oil," which many people believe means that they need to add oil
soon, or have an oil change, the manufacturer should label it "$5000
unless you stop NOW."
From: ASAAR on
On Tue, 26 Jun 2007 04:13:25 -0500, Ron Hunter wrote:

>> Sorry, but when I pointed out your inaccuracies and misstatements,
>> well before you started using your filter, you never even attempted
>> to disprove any of my corrections. You simply ignored them and
>> continued spouting the same inaccurate facts. It's *you* that needs
>> to change your ways, but I'll be quite surprised if you do. We can
>> start with one of your repeated points of misinformation, that
>> cameras don't or can't have battery meters for NiMH cells due to
>> their supposedly flat discharge curve. There's plenty of evidence
>> that that is untrue, and I could repeat some of the reasons for you
>> if you're willing, but I'm amazed that a self-proclaimed "battery
>> expert" wouldn't know this already.
>>
> Isn't a battery meter on a device using NiMH batteries rather like a
> radar detector with such a short range that it only tells you you have
> been caught? Given the discharge curve, it need only be a dot in the
> LCD display that says your battery is below the cutoff voltage. Still,
> my camera do have such a warning, and it really means what it says
> because only a couple of pictures can be taken with that warning on
> before ugly things start to happen.

Not at all, and I see that the spouter of disinformation has
already chimed in to support this erroneous view of yours. In
addition to the highly accurate 14 segment LCD display that I have
on one of my radios, which unfortunately you can't see, but which
would corroborate the accuracy of NiMH battery meters, there are two
other devices that convincingly show that you're mistaken.

First, I had Palm PDAs that ran battery meter software which had
calibration settings for alkaline, NiMH and Li-Ion batteries.
Several used two AAA batteries and another used either four AAA
batteries or a Li-Ion battery pack. The voltage was displayed by
the software to 0.01 volt, and the warning level triggered at 2.10
volts for the two AAA PDAs (which could be user modified) and the
current voltage was always displayed in a tiny font on the screen.
Battery life was about 50 hours and when the warning triggered at
2.10 volts, the PDAs easily had more than 10 hours of battery life
remaining, since the PDAs could still operate until the voltage
dropped slightly below 1.90 volts. Using alkaline batteries, that
was no problem. Using NiMH batteries, the voltage would quickly
plummet after 2.00 volts was reached. But until that 2.00 volt
threshold was reached, each 0.01 volts was good for about one hour
of battery life, both for alkaline and NiMH batteries. This battery
meter was extremely accurate and reliable. Being able to predict
the end of a 50 hour battery life to within a couple of minutes is
probably good as any high tech. Li-Ion battery meter has ever
achieved.

The other example is one which you and many others may be familiar
with. My last several cell phones used Li-Ion batteries, and they
all used a multi-segment vertical display to show both the signal
strength and the battery level. Several previous cell phones used
NiMH batteries and had the same type of signal strength and battery
meters. They both performed about the same, with the segments
winking out at a uniform rate over the 6 to 7 days worth of life
each battery charge was good for. The NiMH batteries did NOT cut
out without a warning as you suggested. There was absolutely no
difference between how the battery meter worked, for both NiMH and
Li-Ion batteries. Anyone that has used cell phones for more than
the last couple of years probably has used models that worked with
NiMH batteries. I highly doubt that I'm the only one that had
models with decent battery meters.

There is *no* reason why decent battery meters can't be designed
into cameras that use NiMH AA batteries. If you've only used
devices that show tiny, virtually useless dots, or warnings that
come so late that they didn't provide enough warning time, that's
the fault of the device's designers, and they did a poor job.
Similarly, if your camera does "ugly things" only several shots
after the warning appears, that also indicates poor design, unless
I'm misinterpreting what you said. A well designed camera should do
an orderly shutdown well before any type of battery gives out. If
yours doesn't, the camera's designers were incompetent. I suspect,
though, that you're just talking about experiencing an orderly,
intentional shutdown, and not something like losing power after a
shot but before the image was completely written to the flash card.
That, I agree, would be pretty "ugly".

From: batterylogic on
On 12 Jun, 15:51, SMS <scharf.ste...(a)geemail.com> wrote:
> Allen wrote:
> > SMS wrote:
> > <snip>
> >> Yeah, that's the bottom line, though the low-end cameras like the
> >> Canom A series use AA batteries because it saves the manufacturer
> >> money. With the Sanyo eneloop batteries, at least one of the many
> >> problems of AA batteries is solved (self-discharge) though the other
> >> problems remain.
>
> > Please list at least some of the "many problems" of AA batteries.
> > Allen
>
> See "http://batterydata.com". In the table of contents click on
> "Advantages of Li-Ion Batteries/Disadvantages of NiMH batteries (AA/AAA)"
>
> But here's a list:
>
> -High Self-Discharge Rate
> -Lower Number of Charge/Discharge Cycles
> -Lower Energy Density by Weight and Volume
> -Inconvenience of charging and swapping and keeping track of multiple
> packs of multiple cells
> -Poor Cold weather performance
> -Lower reliability of devices that use them
> -Lower reliability of batteries over long periods of non-use
> -No protection circuitry
> -No accurate charge level indication in device is possible
>
> I do have cameras that use AA batteries, as well as ones that use Li-Ion
> batteries. While I've learned to "never say never," it'd be highly
> unlikely that I'd buy another camera that used AA batteries.
>
> The advantages of Li-Ion are overwhelming, while the sole advantage of
> AA is that if you find yourself ITMON (in the middle of nowhere) with no
> vehicle and no AC power, you can always buy some AA batteries at that
> little country store.
>
> Even the price of AA batteries isn't really an advantage if you look at
> the big picture. As long as the camera you use has after-market Li-Ion
> packs available, the price difference is small to non-existent.
>
> It's not for no reason that all the high end cameras use Li-Ion, not to
> mention all cell phones, PDAs, laptop computers, etc. Even some high end
> flashlights and bicycle lights now use Li-Ion rechargeables.

Just go straight to http://www.batterylogic.co.uk and treat yourself
to some Hybrio batteries and the Technoline iCharger. Your investment
will pay for itself in no time and you will have a very good charger
and batteries. There are so many things that use AA/AAA batteries you
will be sorted for a long time to come!