I recently purchased a Canon a630 (following
recommendations in this very group).
Lovely camera. Enjoyed using it.
Got 550 shots (with lots of display use
and reviewing) from the set of Alkaline
batteries supplied with it.
When I replaced them with a brand new,
fully charged, set of 2700 mAH NiMh
I only got 70 shots before the
red "battery low" icon appeared.
Worse, I put a second set of charged
2100 mAH batteries in, and these were
immediately reported as battery low.
I have metered (vintage AVO mk8!) both
sets of NiMh batteries and all read 1.25
volts, which is what the advanced manual
says "branded" Canon NiMh batteried
would yield.
The Alkaline batteries were
presumably much high voltage, at
1.5 V nominal.
> I have metered (vintage AVO mk8!) both
> sets of NiMh batteries and all read 1.25
> volts, which is what the advanced manual
> says "branded" Canon NiMh batteried
> would yield.
Does your meter put a load on the battery? Even dead batteries can
read full voltage when no load is applied (and a volt meter draws VERY
little current).
FWIW, I've been using nicad in my a710 without a problem, and in fact,
was surprised how long the batteries have lasted. However, I haven't
used a flash, either.
Larry Bud wrote:
>> I have metered (vintage AVO mk8!) both
>> sets of NiMh batteries and all read 1.25
>> volts, which is what the advanced manual
>> says "branded" Canon NiMh batteried
>> would yield.
>
> Does your meter put a load on the battery? Even dead batteries can
> read full voltage when no load is applied (and a volt meter draws VERY
> little current).
Yes, especially a good one.
I will attempt to improvise a "reasonable" load to check
further.
On Mon, 25 Jun 2007 10:46:08 +0100, bugbear wrote:
> Lovely camera. Enjoyed using it.
> Got 550 shots (with lots of display use
> and reviewing) from the set of Alkaline
> batteries supplied with it.
>
> When I replaced them with a brand new,
> fully charged, set of 2700 mAH NiMh
> I only got 70 shots before the
> red "battery low" icon appeared.
>
> Worse, I put a second set of charged
> 2100 mAH batteries in, and these were
> immediately reported as battery low.
>
> I have metered (vintage AVO mk8!) both
> sets of NiMh batteries and all read 1.25
> volts, which is what the advanced manual
> says "branded" Canon NiMh batteried
> would yield.
>
> The Alkaline batteries were
> presumably much high voltage, at
> 1.5 V nominal.
>
> Has anyone else had trouble like this?
No. I have two similar cameras, a Fuji S5100 and a Canon A620 and
they both are able to take more shots with NiMH batteries and far
more with NiMH batteries if the flash is frequently used. Since
you're getting the expected usage from alkaline batteries, which
very quickly drop well below 1.5 volts with some use, it seems that
there may be some problem with either your NiMH batteries or with
the charger that you're using. The charger is the prime suspect if
it doesn't have 4 individual charging circuits as well as an LED (or
LCD display) for each AA cell. Or it could be that the only thing
that's defective is the "battery low" circuit's trigger level.
If you check your manual, you'll see that the use of the LCD
shouldn't be any kind of a problem, since it uses so little battery
power that whether alkalines or NiMH batteries are used, the LCD
display can be used for 20 hours of viewing. If you have no good
way to check the batteries or the charger, get a cheap $5 battery
tester from Radio Shack, the kind that has no LEDs, just an
old-fashioned analog needle-pointer meter. I'm assuming that your
vintage meter has a much too high input resistance/impedance to be
an effective battery tester. Alternatively, you could use it while
the batteries are in a cheap battery holder, under a 150 or 220 ohm
load. Then after charging the NiMH batteries, use them in your A630
while you take lots of test shots with the flash disabled.
When the "battery low" indicator comes on, continue using the
camera until the voltage is so low that the camera powers off by
itself. If this doesn't happen until you've taken well over 1,000
shots, then there's nothing wrong with the camera other than a less
than useful "battery low" warning indicator. If the batteries go
flat before approaching 1,000 shots, take them out and test each one
with the battery tester to see if any one or two seem noticeably
weaker than the others. If so, you'll then have to determine if the
problem is with the batteries or with your charger.
On Mon, 25 Jun 2007 10:46:08 +0100, bugbear wrote:
> I recently purchased a Canon a630 (following
> recommendations in this very group).
>
> Lovely camera. Enjoyed using it.
> Got 550 shots (with lots of display use
> and reviewing) from the set of Alkaline
> batteries supplied with it.
>
> When I replaced them with a brand new,
> fully charged, set of 2700 mAH NiMh
> I only got 70 shots before the
> red "battery low" icon appeared.
>
> Worse, I put a second set of charged
> 2100 mAH batteries in, and these were
> immediately reported as battery low.
>
> I have metered (vintage AVO mk8!) both
> sets of NiMh batteries and all read 1.25
> volts, which is what the advanced manual
> says "branded" Canon NiMh batteried
> would yield.
>
> The Alkaline batteries were
> presumably much high voltage, at
> 1.5 V nominal.
>
> Has anyone else had trouble like this?
>
> BugBear
Similar situation with my wife's niken 2100. We've stopped using
rechargeables in it and now use Lithium AAs. FWIW Sanyo (enerloop) and
rayovac (hybrid) NiMH batteries claim to have eliminated 'shelf life'
problems. Standard NiMH batteries loose charge at a significant rate.
One point to note with NiMh is that you only achieved the full capacity discharge after a few charge and discharge cycles.
The Avo 8 input resistance... that is the loading across a circuit is 20,000 ohms per volt, so if you are measuring 3 volts the circuit will see 3 x 20K ohms hence ohms per volt, by Ohms law dividing the applied voltage by it's resistance (V/R = I) the meter will draw a current of only 150uA or 0.00015 Amp, your camera will draw considerably more current.
As one reply suggested you can not measure the voltage on a battery without a load because of it's internal resistance, this rises as the battery discharges, all that you would be measuring is the open circuit terminal voltage and the current drawn would be that of the measuring device.
One question that 'may' be raised is how are you charging them are they being fully charged?
Normally batteries are charged at about a tenth of their total capacity for around 16 hours, which means 210mA for 16 hours.
NiMh are far better than NiCads in terms of their capacity and it's memory retention isn't as bad as Nicads, yet again far better are the Lithium Ion batteries because of their low self discharge rate but are more expensive.
In article <467f8ee0$0$8726$ed2619ec@ptn-nntp-reader02.plus.net>, bugbear <bugbear@trim_papermule.co.uk_trim> wrote:
>I recently purchased a Canon a630 (following
>recommendations in this very group).
>
>Lovely camera. Enjoyed using it.
>Got 550 shots (with lots of display use
>and reviewing) from the set of Alkaline
>batteries supplied with it.
>
>When I replaced them with a brand new,
>fully charged, set of 2700 mAH NiMh
>I only got 70 shots before the
>red "battery low" icon appeared.
>
>Worse, I put a second set of charged
>2100 mAH batteries in, and these were
>immediately reported as battery low.
>
NiMh batteries need a few series of charge / discharge cycles before they get
to full capacity
>I have metered (vintage AVO mk8!) both
>sets of NiMh batteries and all read 1.25
>volts, which is what the advanced manual
>says "branded" Canon NiMh batteried
>would yield.
>
>The Alkaline batteries were
>presumably much high voltage, at
>1.5 V nominal.
>
>Has anyone else had trouble like this?
>
> BugBear
bugbear wrote:
> Larry Bud wrote:
>>> I have metered (vintage AVO mk8!) both
>>> sets of NiMh batteries and all read 1.25
>>> volts, which is what the advanced manual
>>> says "branded" Canon NiMh batteried
>>> would yield.
>>
>> Does your meter put a load on the battery? Even dead batteries can
>> read full voltage when no load is applied (and a volt meter draws VERY
>> little current).
>
> Yes, especially a good one.
>
> I will attempt to improvise a "reasonable" load to check
> further.
You really want to do a pulse load test. A few high end chargers are
able to do this, as well as a standalone tester.
I think you may have one weak cell in each set.
See "http://www.thomas-distributing.com/zts-mini-mbt-battery-tester.htm"
In article <davy.2srhjj@no.email.invalid>,
davy <davy.2srhjj@no.email.invalid> wrote:
> One point to note with NiMh is that you only achieved the full capacity
> discharge after a few charge and discharge cycles.
>
> The Avo 8 input resistance... that is the loading across a circuit is
> 20,000 ohms per volt, so if you are measuring 3 volts the circuit will
> see 3 x 20K ohms hence ohms per volt, by Ohms law dividing the applied
> voltage by it's resistance (V/R = I) the meter will draw a current of
> only 150uA or 0.00015 Amp, your camera will draw considerably more
> current.
20,000 ohms/V refers to the FS Voltage SETTING. That is, if you put the
meter on the 30V setting the resistance will be 600,000 ohms.
>
> As one reply suggested you can not measure the voltage on a battery
> without a load because of it's internal resistance, this rises as the
> battery discharges, all that you would be measuring is the open circuit
> terminal voltage and the current drawn would be that of the measuring
> device.
>
Measuring OC voltage is still useful, such as looking for bad cells.
> One question that 'may' be raised is how are you charging them are they
> being fully charged?
>
> Normally batteries are charged at about a tenth of their total capacity
> for around 16 hours, which means 210mA for 16 hours.
>
Few modern battery charges take 16 hours to charge, 4 is about the most
you'll find.
--
Clark Martin
Redwood City, CA, USA Macintosh / Internet Consulting
"I'm a designated driver on the Information Super Highway"
bugbear wrote:
> Larry Bud wrote:
>>> I have metered (vintage AVO mk8!) both
>>> sets of NiMh batteries and all read 1.25
>>> volts, which is what the advanced manual
>>> says "branded" Canon NiMh batteried
>>> would yield.
>>
>> Does your meter put a load on the battery? Even dead batteries can
>> read full voltage when no load is applied (and a volt meter draws VERY
>> little current).
>
> Yes, especially a good one.
>
> I will attempt to improvise a "reasonable" load to check
> further.
OK; this morning, I fiddled around with some
wire and a torch bulb.
A single battery from the 2100 mAH set
reads 1.25 volts "open circuit", and when driving
..5 amp though a bulb still held at 1.15 volts.
Of the 2 sets of 4 NiMh batteries I have, one
is old 2100 mAH (I used it in my previous Canon a60 and Canon a510)
and one is new (2700 mAH, first use).
I will try to rig a more convenient battery-under-load
testing circuit and report back.
I do have a "proper" NiMh charger
(Uniross, model # forgotten), with separate
indicator LED for each battery.
Issues with NiMh batteries in Canon a630? 
Linear Mode
