From: ASAAR on
On Tue, 12 Jun 2007 07:51:29 -0700, Fudmeister S. Scharf stated:

>> Please list at least some of the "many problems" of AA batteries.
>> Allen
> . . .
>
> But here's a list:
>
> -High Self-Discharge Rate

More of your nonsense and apparent disinformation. Li-Ion
batteries do have a lower self-discharge rate than the standard, old
type NiMH batteries. But the new type (Sanyo Eneloop, RayOVac
Hybrid, etc.) of precharged NiMH batteries have much lower
self-discharge rates than Li-Ion. The self discharge rates of
alkaline and lithium AA batteries is so low that it's silly to even
think of them having *any* self discharge rate. Both alkalines and
lithium AA batteries have shelf lives many years longer than the
life of the typical camera that they're used in.


> -Lower Number of Charge/Discharge Cycles

Another of your repeated, dishonest claims. Most NiMH battery
manufacturers claim at least 1,000 charge/discharge cycles. At
least one makes a more modest claim of 500 cycles. Name a Li-Ion
manufacturer that claims more than 1,000 charge/discharge cycles.

But comparing the number of cycles is pointless, because
virtually no Li-Ion battery, at least those used in most consumer
cameras, will last long enough to undergo even 100 charge/discharge
cycles. Pros might exceed several hundred, but most people don't
use their cameras so heavily. Even *you* have stated, right here,
that Li-Ion batteries have a life of about 3 years. Let's see, with
1,000 charge cycles spread out over 3 years, that amounts to needing
to recharge the Li-Ion battery every day. At about 300 shots per
charge, that amounts to over 100,000 shots per year. Most people
take several hundred shots per year. Some dedicated amateurs might
exceed several thousand. At these rates the batteries would need to
be recharged from a couple of times/year to a couple of dozen times
per year. And by the time the Li-Ion batteries would need to be
replaced, it's unlikely that the batteries would have reached a
dozen charge/discharge cycles for most people, or 100 cycles for any
but the most atypical active amateurs

In other words, your claim that Li-Ion batteries provide a greater
number of charge/discharge cycles is not only incorrect, it's a
bogus, meaningless claim, since virtually nobody that treats their
batteries properly (ie, they don't kill them by using them
improperly) will ever utilize the potential of either Li-Ion or NiMH
batteries.


> -Lower Energy Density by Weight and Volume

Yes, at least for NiMH AA batteries where weight is concerned.
But the energy density of NiMH batteries has greatly increased over
the years. My early 900mAh NiMH batteries contained 1/3 the energy
of today's 2,700mAh batteries. So the difference between the energy
density of Li-Ion and today's NiMH batteries with respect to volume
is quite small. My latest Canon P&S that uses AA NiMH batteries can
take up to 1,600 shots per charge. Can you name another P&S camera
that uses Li-Ion batteries that comes close to 1,600 shots per
charge? If not, how about 800 shots per charge?


> -Inconvenience of charging and swapping and keeping track of multiple
> packs of multiple cells

You're still using bogus arguments, talking about cameras that
were sold at least 5 years ago. Many of today's cameras can and do
go several months on a single charge. That has been reported by
many people in this newsgroup over the last couple of years. They
no more need multiple sets of batteries than cameras that use Li-Ion
batteries. If fact, it's worse for many cameras that use Li-Ion
batteries, as I'm not aware of any that can go for over 1,000 shots
per charge. They would NEED multiple battery packs. My Fuji and
Canon P&S cameras don't, so I don't even think about bringing more
than the batteries installed in the camera unless I'll be away
taking many pictures for several days. Even then I don't *have* to
bring a second set along, since if need be, I can pick up some more
AA batteries wherever I happen to be, 24x7.


> -Poor Cold weather performance

Also misleading. Li-Ion performs better at moderately low
temperatures than alkaline and NiMH batteries. But when the
temperatures get very low, Li-Ion batteries also suffer, and quit
working when lithium AA batteries keep working without (so to speak)
raising a sweat. You are aware, aren't you, that lithium AA
batteries are rated for use in temperatures as low as 40 below zero?
If you doubt it, check one of Energizer's lithium AA packages, where
the temperature range is clearly printed. Li-Ion batteries don't
come close to matching that low temperature ability.


> -Lower reliability of devices that use them

Not that I've ever noticed. I've had a couple of cell phones that
had to be replaced due to battery problems. They used Li-Ion
batteries. My older cell phones that use NiMH batteries still work,
and the only reason why I stopped using them was related to
switching to another carrier that had a more economical plan.


> -Lower reliability of batteries over long periods of non-use

Absolutely wrong, FUDmeister Flash. If unused for really long
periods, NiMH batteries usually have no problems that a couple of
charge cycles (or a charger's reconditioning cycle) won't usually
cure. I'm still using a large number of 1,600 mAh RayOVac NiMH
batteries, most of which have sat unused at one time or another for
a year or two. Li-Ion batteries on the other hand can become
completely inoperable, and won't be able to be charged at all if
they go too long between charges. This is well known, and several
Li-Ion battery manufacturers include instructions with their battery
packs, warning that a slight charge (just a few minutes is enough)
is needed at least every 6 months. And with shelf lives of 8 years
and 15 years, this is *not* a problem for alkaline and lithium
batteries.


> -No protection circuitry

Because they don't need protective circuits. Li-Ion batteries
have been notorious for either exploding, or more usually, creating
intense fires. Protective circuits aren't used where they aren't
needed. Even single cell lithium AA batteries have protective
circuits (internal) that alkaline and NiMH don't require. Why do
you think that NiMH and even much lower capacity NiCd batteries
perform much better in speedlights than lithium AA batteries? Hint:
The lithium battery's protective circuit.


> -No accurate charge level indication in device is possible

This is a flat out lie. It's only economics that prevents
accurate charge level indicators from being used for NiMH or NiCD
batteries. I've already given an example of a very accurate battery
meter used with NiMH batteries, but your Li-Ion zealotry may have
something to do with your repeating this nonsense.

From: SMS on
Thomas T. Veldhouse wrote:

> As for that. If you use your flash a lot and often, then look at PowerEx or
> Sanyo 2700mAh NiMH batteries. If you tend to leave your flash unused for a
> couple weeks at a time, I would consider buying the low discharge batteries.
> I own several Rayovac Hybrid 2100mAh batteries and several Sanyo Eneloop
> 2000mAh batteries. Both of these batteries tend to exceed the rated
> capacities on most cases, however I did more variance with the Rayovac
> batteries. These should hold a charge between uses even when months apart.

I think the issue here is that the camera is used infrequently. That
being the case, the original poster might want to consider using either
Sanyon eneloop, or Energizer lithium non-rechargeables.

My son has an old A60, similar to the original poster's A70, and the
Energizer lithium non-rechargeables work well considering that he uses
the camera infrequently. Next time I see the eneloops on sale I might
buy four of them.
From: Thomas T. Veldhouse on
ASAAR <caught(a)22.com> wrote:
>
>> -No accurate charge level indication in device is possible
>
> This is a flat out lie. It's only economics that prevents
> accurate charge level indicators from being used for NiMH or NiCD
> batteries. I've already given an example of a very accurate battery
> meter used with NiMH batteries, but your Li-Ion zealotry may have
> something to do with your repeating this nonsense.
>

It is VERY possible. Simply applying the load and checking the volage will do
it. Consider this fine piece of equipment.

http://www.thomasdistributing.com/zts-mini-mbt-battery-tester.htm

--
Thomas T. Veldhouse

If you took all of the grains of sand in the world, and lined
them up end to end in a row, you'd be working for the government!
-- Mr. Interesting


From: SMS on
Thomas T. Veldhouse wrote:

> It is VERY possible. Simply applying the load and checking the volage will do
> it. Consider this fine piece of equipment.
>
> http://www.thomasdistributing.com/zts-mini-mbt-battery-tester.htm

LOL, so how often should someone remove the batteries from their camera
to test them? I've had that battery tester on the web site for more than
a year. It's a workaround to the issue, albeit a clumsy one.

I should have said that it's not possible inside the camera. Or perhaps
more accurately, it's too expensive to implement the pulse load test
inside the camera, especially considering the manufacturers are cutting
every possible expense on the AA powered cameras in the first place.

It's an inherent characteristic of NiMH batteries that the voltage
discharge curve is so flat. This isn't necessarily a bad thing, but it
does mean that it's non-trivial to measure remaining capacity, and it
results in the lack of accurate battery level indicator in-camera for AA
powered cameras.

Steve
"http://batterydata.com/"



From: Thomas T. Veldhouse on
SMS <scharf.steven(a)geemail.com> wrote:
> LOL, so how often should someone remove the batteries from their camera
> to test them? I've had that battery tester on the web site for more than
> a year. It's a workaround to the issue, albeit a clumsy one.
>
> I should have said that it's not possible inside the camera. Or perhaps
> more accurately, it's too expensive to implement the pulse load test
> inside the camera, especially considering the manufacturers are cutting
> every possible expense on the AA powered cameras in the first place.
>
> It's an inherent characteristic of NiMH batteries that the voltage
> discharge curve is so flat. This isn't necessarily a bad thing, but it
> does mean that it's non-trivial to measure remaining capacity, and it
> results in the lack of accurate battery level indicator in-camera for AA
> powered cameras.
>

You can get reasonably accurate capacity readings based on voltage alone, but
it doesn't work well when the battery becomes damaged [or nears end-of-life].
The MB-D200 grip for the Nikon D200 takes any AA battery and of course the
standard LiIon batteries. The D200 can be configured to know that it is using
NiMH batteries and does a good job with it.

I simply stated it is possible, not that it is practical for in camera field
use on cheap consumer point-and-shoots.

--
Thomas T. Veldhouse

If you took all of the grains of sand in the world, and lined
them up end to end in a row, you'd be working for the government!
-- Mr. Interesting