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I was in Best Buy today, looking at the Canon A540 and SD600. The A540
takes 2 AA batteries, and the SD600 takes one of those rectangular Lithium
Ion batteries. A couple of Best Buy employees said that the Lithium Ion
battery holds a lot more charge than NiMH batteries. They said the SD600
camera would be able to take around 200 shots before the battery ran out,
while the A540 would only be able to take around 30-40 shots before the
batteries ran out.

I am extremely skeptical of what they said. If what they said is true,
then there is no reason why any camera on the market today would take AA
batteries instead of the Lithium Ion battery.

So were they right or wrong?

"void" <> wrote in message
news...
>I was in Best Buy today, looking at the Canon A540 and SD600. The A540
>takes 2 AA batteries, and the SD600 takes one of those rectangular Lithium
>Ion batteries. A couple of Best Buy employees said that the Lithium Ion
>battery holds a lot more charge than NiMH batteries. They said the SD600
>camera would be able to take around 200 shots before the battery ran out,
>while the A540 would only be able to take around 30-40 shots before the
>batteries ran out.
>
> I am extremely skeptical of what they said. If what they said is true,
> then there is no reason why any camera on the market today would take AA
> batteries instead of the Lithium Ion battery.
>
> So were they right or wrong?

Strictly speaking they are wrong, the NiMh batteries may well be larger in
capacity but as the stored charge is used the voltage will drop and
particularly in cameras this can be a problem, LIon batteries on the other
hand should hold a higher voltage as the stored charge reduces and therefore
may keep operating even though the stored charge is less.

"void" <> writes:
> I am extremely skeptical of what they said. If what they said is
> true, then there is no reason why any camera on the market today would
> take AA batteries instead of the Lithium Ion battery.
>
> So were they right or wrong?

The practical answer is, it will burn through alkaline AA cells pretty
fast (they're not built for the high current that a camera needs) but
NiMH rechargeable AA cells will run it for a long time, at least as
long as the small li ion packs. I have the A530 (similar to A540) and
charge up the AA cells once in a while. I really like being freed
from proprietary batteries.

In article <>,
"void" <> wrote:

> I was in Best Buy today, looking at the Canon A540 and SD600. The A540
> takes 2 AA batteries, and the SD600 takes one of those rectangular Lithium
> Ion batteries. A couple of Best Buy employees said that the Lithium Ion
> battery holds a lot more charge than NiMH batteries. They said the SD600
> camera would be able to take around 200 shots before the battery ran out,
> while the A540 would only be able to take around 30-40 shots before the
> batteries ran out.
>
> I am extremely skeptical of what they said. If what they said is true,
> then there is no reason why any camera on the market today would take AA
> batteries instead of the Lithium Ion battery.
>
> So were they right or wrong?

LiIon batteries have about the same, or maybe a little less, amp hour
rating as NiMH but at three times the voltage, half the weight, and with
less self-discharge.

The downside to LiIon batteries is that they're expensive and their life
can be shorter than NiMH.


http://en.wikipedia.org/wiki/Lithium_ion_battery
http://en.wikipedia.org/wiki/NiMH

void wrote:
> I was in Best Buy today, looking at the Canon A540 and SD600. The A540
> takes 2 AA batteries, and the SD600 takes one of those rectangular Lithium
> Ion batteries. A couple of Best Buy employees said that the Lithium Ion
> battery holds a lot more charge than NiMH batteries. They said the SD600
> camera would be able to take around 200 shots before the battery ran out,
> while the A540 would only be able to take around 30-40 shots before the
> batteries ran out.
>
> I am extremely skeptical of what they said. If what they said is true,
> then there is no reason why any camera on the market today would take AA
> batteries instead of the Lithium Ion battery.
>
> So were they right or wrong?

Neither. Each battery has its advantages and disadvantages.

NiMH AAs can be swapped out easily, and they're inexpensive to buy, but
store less energy than the Li Ion batteries.

Li Ion batteries are quite expensive, even if they are designed to be
swapped out. But they do have a higher energy density.

My camera is an A540. and it takes NiMH AAs. You can also put Alkaline
batteries in this camera in a pinch, but they don't last too long. Takes
non-rechargeable Lithium batteries also.

--
Pat O'Connell
[note munged EMail address]
Take nothing but pictures, Leave nothing but footprints,
Kill nothing but vandals...

Kevin McMurtrie <> writes:
> LiIon batteries have about the same, or maybe a little less, amp hour
> rating as NiMH but at three times the voltage, half the weight, and with
> less self-discharge.

Nah. Total energy in the same volume is about the same. The lithium
ion cells do weigh less. NiMH self-discharge varies with the cells.
Lithium cells develop it too.

"Pete D" <> wrote in message
news:45628ff3$0$1602$...
>
> "void" <> wrote in message
> news...
>>I was in Best Buy today, looking at the Canon A540 and SD600. The
>>A540 takes 2 AA batteries, and the SD600 takes one of those
>>rectangular Lithium Ion batteries. A couple of Best Buy employees
>>said that the Lithium Ion battery holds a lot more charge than NiMH
>>batteries. They said the SD600 camera would be able to take around
>>200 shots before the battery ran out, while the A540 would only be
>>able to take around 30-40 shots before the batteries ran out.
>>
>> I am extremely skeptical of what they said. If what they said is
>> true, then there is no reason why any camera on the market today
>> would take AA batteries instead of the Lithium Ion battery.

They were wrong, but not for the reasons mentioned. The sales geeks
got their info mixed up.

Using Alkaline AA cells is a bad idea because they are not high
current discharge capable like rechargeables, so they tend to work for
only a few dozen shots before their voltage level drops enough that
they appear dead to the camera. Allowing Alakaline cells to "rest" for
a while may help get a few more shots, but they're simply a poor
choice for high current devices like cameras.

The Li-Ion and Ni-MH cells can produce higher current levels and the
camera makes better use of their performance.

>> So were they right or wrong?
>
> Strictly speaking they are wrong,

No, strictly speaking they were RIGHT. Lithium-based batteries have a
higher charge density per weight than any other rechargeable cell.

The problem is the confusion with AA and rechargeables.

> the NiMh batteries may well be larger in capacity but as the stored
> charge is used the voltage will drop and particularly in cameras
> this can be a problem, LIon batteries on the other hand should hold
> a higher voltage as the stored charge reduces and therefore may keep
> operating even though the stored charge is less.

I'm sorry but you're wrong again.

Li-Ion discharge voltage also drops, but in a more steady drop (linear
curve) than Ni-MH or Ni-Cad cells, which tend to dip, then level off,
then drop off at the end of charge (stepped curve). Li-Ion drops
steadily and smoothly as the charge level drops - they do not hold
voltage levels while discharging at all.

Please research battery technology from reputable sources before
spreading incorrect information. We already have enough misinformation
about technology as it is.

I once had to do research into various battery technologies for a
work-related contract purchase. If you want specific quotes, try
places like:

http://www.hardingenergy.com/

http://www.electricitystorage.org/

"Bill" <> wrote in message
news:.. .
> "Pete D" <> wrote in message
> news:45628ff3$0$1602$...
>>
>> "void" <> wrote in message
>> news...
>>>I was in Best Buy today, looking at the Canon A540 and SD600. The A540
>>>takes 2 AA batteries, and the SD600 takes one of those rectangular
>>>Lithium Ion batteries. A couple of Best Buy employees said that the
>>>Lithium Ion battery holds a lot more charge than NiMH batteries. They
>>>said the SD600 camera would be able to take around 200 shots before the
>>>battery ran out, while the A540 would only be able to take around 30-40
>>>shots before the batteries ran out.
>>>
>>> I am extremely skeptical of what they said. If what they said is true,
>>> then there is no reason why any camera on the market today would take AA
>>> batteries instead of the Lithium Ion battery.
>
> They were wrong, but not for the reasons mentioned. The sales geeks got
> their info mixed up.
>
> Using Alkaline AA cells is a bad idea because they are not high current
> discharge capable like rechargeables, so they tend to work for only a few
> dozen shots before their voltage level drops enough that they appear dead
> to the camera. Allowing Alakaline cells to "rest" for a while may help get
> a few more shots, but they're simply a poor choice for high current
> devices like cameras.
>
> The Li-Ion and Ni-MH cells can produce higher current levels and the
> camera makes better use of their performance.
>
>>> So were they right or wrong?
>>
>> Strictly speaking they are wrong,
>
> No, strictly speaking they were RIGHT. Lithium-based batteries have a
> higher charge density per weight than any other rechargeable cell.
>
> The problem is the confusion with AA and rechargeables.
>
>> the NiMh batteries may well be larger in capacity but as the stored
>> charge is used the voltage will drop and particularly in cameras this can
>> be a problem, LIon batteries on the other hand should hold a higher
>> voltage as the stored charge reduces and therefore may keep operating
>> even though the stored charge is less.
>
> I'm sorry but you're wrong again.
>
> Li-Ion discharge voltage also drops, but in a more steady drop (linear
> curve) than Ni-MH or Ni-Cad cells, which tend to dip, then level off, then
> drop off at the end of charge (stepped curve). Li-Ion drops steadily and
> smoothly as the charge level drops - they do not hold voltage levels while
> discharging at all.
>
> Please research battery technology from reputable sources before spreading
> incorrect information. We already have enough misinformation about
> technology as it is.
>
> I once had to do research into various battery technologies for a
> work-related contract purchase. If you want specific quotes, try places
> like:
>
> http://www.hardingenergy.com/
>
> http://www.electricitystorage.org/
>

Perhaps you should learn to interpret your infomation sources better. What I
said still stands up.

Cheers.

Pete D
NiMH Voltage

The discharge voltage profile of a NiMH battery is considered “flat” (see
Figure 3.7.2 C/10 Discharge

Profile @ 25°C) and varies with the rate of discharge and temperature. As a
fully charged battery is

discharged the voltage begins at about 1.5 volts followed by a sharp drop to
around 1.3 volts. The

voltage remains between 1.3 to 1.2 volts for about 75% of the profile until
a second sudden drop in

voltage occurs as the useful capacity of the battery begins to deplete.



Lithium Ion



5.4 Rate Capability

Table 5.4.1: Charge/Discharge Chemical Reactions

Typical Performance Characteristics of Lithium Ion Batteries



5.5 Discharge Characteristics

At a constant current discharge rate, the lithium ion battery maintains a
relatively flat voltage discharge profile

with a steep decrease in the profile near the end of discharge. The battery
should not be discharge to less than

3.0 volts per battery.

void wrote:
> I was in Best Buy today, looking at the Canon A540 and SD600. The A540
> takes 2 AA batteries, and the SD600 takes one of those rectangular
> Lithium Ion batteries. A couple of Best Buy employees said that the
> Lithium Ion battery holds a lot more charge than NiMH batteries. They
> said the SD600 camera would be able to take around 200 shots before the
> battery ran out, while the A540 would only be able to take around 30-40
> shots before the batteries ran out.

The Best Buy employees are full of it. According to
"http://www.dcresource.com/reviews/canon/powershot_a540-review/" the
A540 is good for 360 shots, while the SD600 was rated at 160 shots.

> I am extremely skeptical of what they said.

I wouldn't expect the employees of the big-box electronics retailers to
know anything about the products they are selling, other than which
products have the better spiffs.

> If what they said is true,
> then there is no reason why any camera on the market today would take AA
> batteries instead of the Lithium Ion battery.

Sure there is. If there was a Li-Ion pack the same size as the two AAs
in the A540, then the A540 would get about 500 shots from a battery. The
reason the manufacturers use AA batteries is because it saves them the
expense of providing a rechargeable battery and charger. The AA
batteries are less energy dense for a given weight and volume, and have
other performance issues that may or may not be important considerations
for you, but the main reason they are used in the low-end cameras is
because they're cheap.

On Mon, 20 Nov 2006 22:52:17 -0600, void wrote:

> I was in Best Buy today, looking at the Canon A540 and SD600. The A540
> takes 2 AA batteries, and the SD600 takes one of those rectangular Lithium
> Ion batteries. A couple of Best Buy employees said that the Lithium Ion
> battery holds a lot more charge than NiMH batteries. They said the SD600
> camera would be able to take around 200 shots before the battery ran out,
> while the A540 would only be able to take around 30-40 shots before the
> batteries ran out.

Typical store drones that have no qualms about spouting
disinformation. They probably have no idea how many shots the A540
can take and might even be playing games with customers. The next
one might be told just the opposite. Canon, like many other camera
manufacturers is conservative about evaluating battery life, using a
test based on the CIPA standard test procedure, which among other
things takes each shot after fully zooming the lens, and every other
shot uses a full power flash. The manual for the A530/A540 states
that it's good for 90 shots using alkaline batteries or 360 shots
using NiMH AA batteries, in both cases with the LCD monitor turned
on. If the LCD monitor is turned off and the viewfinder is used
instead, alkalines are good for 600 shots and NiMH batteries are
good for 1000 shots per charge. These last numbers may not be using
the CIPA procedure, so perhaps the flash wasn't used for them. But
in any case, if a salesman tries to compare the SD600 using Li-Ion
batteries, the A540 should be compared using NiMH rechargeable
batteries, and whether you use the CIPA test results of 360 shots or
the less stringent test getting 1000 shots, the SD600 with its
unspecified 200 shots falls far behind. Dpreview hasn't reviewed
the SD600, but their review of the SD550, which uses an NB-3L Li-Ion
battery says "Battery life when using LCD not fantastic" and:

> The 4.2v Li-ion battery pack will give you around 150 shots if you use
> the LCD (CIPA standard) - slightly lower than the SD500 thanks to the
> larger screen. If you switch to the optical viewfinder and only use the
> LCD to check your pictures every now and then you can easily get well
> over 550 shots out of a single charge.The battery takes around 100
> minutes to charge fully.

So it's very likely that the SD600 gets about 1/2 the number of
shots per charge than the A540 gets, under similar conditions. High
quality name brand NiMH batteries are much cheaper than Li-Ion
batteries, and you can get good "smart" chargers that can recharge
the NiMH AA cells in as little as 15 minutes.

One other thing to consider. Some people have preferred Li-Ion
batteries because they could hold a charge far longer than
traditional NiMH batteries before they need to be recharged, due to
self-discharge losses. Sanyo and RayOVac have a new type of NiMH
battery that can go 3 or 4 times longer between charges than Li-Ion.
Sanyo's are called "Eneloop" batteries, and RayOVac's are called
"Renewal" batteries (not to be confused with their older, dismal
"Renewal" alkaline batteries). These new NiMH cells can retain much
of their initial charge even after sitting on a shelf for up to two
years, and when charging, any standard NiMH charger can be used.
Unlike most NiMH batteries that require charging before their first
use, these new NiMH types state on their packaging that they're
precharged and can be used immediately.


> I am extremely skeptical of what they said. If what they said is true,
> then there is no reason why any camera on the market today would take
> AA batteries instead of the Lithium Ion battery.
>
> So were they right or wrong?

Your skept-O-meter is working and well calibrated.