Short rechargeable AA battery life in PowerShot A Series

[vivona]

I am researching the cause of short rechargeable Ni-MH battery life in PowerShot A series cameras that use 2 AA batteries. I have the A540, but I have read similar complaints for similar Canon A series cameras.

I would love to hear how many pictures you usually get on a set of freshly charged set of AA batteries. To keep things constant, I need to know how many shots you get with all flash shots and the LCD on. With alkalines, I get 90, but with Ni-MH I sometimes only get about 5 to 10 before the low battery indicator begins flashing and a total of 20-30 before the camera quits. With each reply, please tell the camera model, the number of shots and the brand and maH rating of the batteries use are using.

I am NOT referring to the recall of a small number of A540 and A530 cameras that have a incorrectly formed battery cover spring. My camera is not included in that recall and the battery cover spring is formed okay.

I am referring to cameras that will get the expected 90 shots with alkalines, but with some Ni-MH batteries, the low battery warning indicator will come on after a few shots.

What I have found is that all Ni-MH batteries drop their voltage when first being used, then stay at a steady voltage for the remainder of their useful charge before the voltage drops again. If you have a Ni=MH battery that drops too low for the PowerShot's battery monitoring circuitry, you will get very short battery life.

I plan to set up a test using the external power connector and a variable power supply to find the exact voltages that the A540 shows the low battery indicator and the "change the batteries" message (assuming that these functions are active when voltage is supplied from the external power connector). I can then compare the voltages to the discharge voltage curve of Ni-MH batteries using the voltage graphs at http://www.users.on.net/~mhains/Reviews.html. That should document how compatable the A540 is with the typical selection of rechargable batteries. The voltage graphs at that website are for 4 batteries, so I will use half the voltage for the 2 batteries used in the A540. For now, note how quickly the rechargable batteries drop in voltage before the voltage graph flattens out. (click on the "click here" in the Voltage graph column). If the A540 quits at the bottom of the initial drop in the voltage graph, that would explain the short battery life.

From the graphs at the above website, it appears that the Sanyo eneloops will work the best with the PowerShot cameras. I have ordered a set and will test them soon.

In the meantime, I have a support email going with Canon asking them if they could issue a firmware upgrade that would lower the cutoff voltage for the A540 and similar cameras. I don't know if it is firmware changable, but it is worth asking for.

Don't forget to reply with your experience with rechargeable batteries in a two AA battery PowerShot A Series. I also welcome any other comments on the subject.

Thanks!

[AutoXer]

There may be another variable - brand of rechargable Ni-MH battery. I use Panasonic, Energizer, and Sanyo brands in my A700 and have never had a problem with battery life out of those. However, I have unfortunately also purchased some "off brand" Ni-MH rechargables and found their shooting life to be crap after just a few recharges. So this could be one variable.

Another problem could be the charger - if it isn't a smart enough charger to charge each cell individually, then its possible that it shuts off charging to ALL batteries as soon as ONE battery is at "full charge", and if one of your batteries isn't quite up to snuff it could cause the charging cycle to shut down prematurely, which would look just like lousy battery life from the camera.

Finally, I keep all sets of 4 batteries I purchase together forever (I mark them so a set always stays together), never mixing and matching from another set. So far, no problems, and I use these rechargables in my A700, I used them previously in my Minolta 7Hi, and I use them in my VIvitar 285HV flashes, too.


Jim

[Tanisark]

I have twelve of the Digital Concepts batteries in my camera case (two are in the camera) that I keep fully charged. I only have a 256mb cards which gives me 146 images. On a fully charged set I am able to get between 100 images and a full card before the low battery indicator comes on. That’s with flash and LCD on. Of course, that’s shooting one after the other as soon as the flash recharge cycles and then I have to change the batteries and the card. After the indicator comes on I get maybe five before it dies completely.
The batteries, as I said, are Digital Concepts that I got at Wal-Mart, Ni-MH 2200 mAh, and on a two/four battery 1-hour charger. However, as AutoXer said, it may depend on the charger. I have found that they last longer if I charge only two at a time instead of charging four at a time. I have also found that they don’t “hold” a charge. If they are not used within a week or so I will only get ten to twenty shots. I don’t know if this is normal with rechargeables because these are the only set that I have purchased and I only use them in the camera. My portable scanner has disposable batteries.
I hope this helps. The batteries work okay for what I need but I would be interested in any information that would help extend the battery life and any updates.

[vivona]

There may be another variable - brand of rechargable Ni-MH battery.

That is certainly revealed by the results at http://www.users.on.net/~mhains/Reviews.html. It is surprising how much the voltage curves vary by the different brands. If your camera cuts off at 1.1v per cell, it is easy to see how short the battery life would be for many of the tested batteries. Look at each battery's voltage graph and divide the results by 4 to get the voltage per cell.

On a fully charged set I am able to get between 100 images and a full card before the low battery indicator comes on

Canon claims 360 shots with Ni-MH with the LCD on and every other shot being a flash shot, so you are probably a bit low comparatively, but not unreasonably so.

It seems that the cutoff voltage of the Canon A540 is not universally compatible with the discharge voltage curve of Ni-MH batteries and using a battery that discharges with a voltage above the cutoff voltage is the key. I won't be able to run my voltage test on my A540 until Jan 6th, but when I have the numbers I will post them. In the meantime, I am testing a new set of Energizer 2500maH batteries and have some Sanyo eneloops coming in the mail. The eneloops show a relatively high voltage graph in the tests and should give me much better results.

By the way, my old PowerShot A40 which uses 4 AA cells would get hundreds of shots over several weeks on a single charge of Ni-MH cells. I can take the cells that have discharged to the "change batteries" point in my A540 and put them in the A40 and they will run a long time. So, the current draw and cutoff voltage of a camera certainly has a large part in battery life.

[mishnogram]

I have owned the A610 and currently own an A40 and A520 along with an S2IS. The A520 is really bad for battery life on NiMh for me. I use 2300 mAh and 2500Mah Energizer NiMh on all my cameras. On the A610, I could easily get hundreds of shots as with my A40. On my 520, I'm constantly strugling with keeping them powered up so I've almost stopped using it. My Powershot S2 though has gone as high as 400 plus shots on a single set of 4 batteries.

Chargers and batteries will make a huge difference so keep that in mind. I'm on the market for a Maha charger that's supposed to be one of the best brands out there.

[vivona]

It appears that the A Series PowerShots that use 4 AA cells do not have as much of a problem with battery life as the ones that use 2 cells. With 4 cells, the higher voltage allows the same power with half the current, so the current draw from the cells is 50% less and the voltage doesn't drop nearly as much during use. Looking at it from the other way around, when you go from 4 cells to 2 cells, you have to draw twice the current to get the same amount of power, so battery life suffers.

[vivona]

I have received two replies from Canon in response to my support request email. The first reply referred me to the recall regarding the battery door spring. When I assured them that my camera was not affected by the recall, their second reply told me that different brands of alkaline batteries will perform differently. I had clearly told them twice that alkalines were working fine and that my problem was only with Ni-MH rechargeables.

It appears that Canon support, like many other companies' email support correspondence I have experienced over the years, is merely prewritten responses that are quickly selected based on keywords in your request. I doesn't appear that they actually read through your email. Or, if they do, they are not highly trained and really don't understand the technical stuff. I think at this point I will give up on expecting any help from Canon.

In the meantime, based on the battery graphs at http://www.users.on.net/~mhains/Reviews.html it appears that selecting a battery that maintains a relatively high voltage over the entire discharge voltage curve is the answer. The Sanyo eneloops look real good in this regard. I have a set of Sanyo eneloops coming in the mail. Meanwhile, I did buy a new set of Energizer 2500 mah batteries and they are at 158 pictures and still going fine.

[mishnogram]

Please keep us informed. I'd really like to find a way to improve the battery life of my A520. If the eneloops do it, then I'd definitely go out and buy a set.

[Xorro2k]

Hi, I have recently upgraded from the A40 to the A710 IS and have experienced everything mentioned in the first post with regard to battery life.

I was quite pleased that the A710 only takes 2 batteries, as it meant I would get twice as much use out of the 2 sets of 4 I currently have, however I have been astonished at the speed in which the low battery indicator comes on.

For instance I took around 20 photos in approx 20 mins (some with flash) and the battery indicator came on.

I am using Hahnel 1700mah and Uniross 2000mah, both are NiMh.

I am currently looking for some 2700mah branded cells, but would be interested in hearing more from other users.

P.S. The camera came with 4 alkaline batts which lasted about 3 times longer than the rechargables.

[Robukincan]

Camera: New A630
Batteries: New DURACELL NIMH AA rechargable
Comment: I'm amazed how long these guys last - i get at least 2/300 photos out of them ... they are awesome!

[AutoXer]

Never heard of Hahnel, never heard of Uniross. Try a name-brand battery - Panasonic, Energizer, Fuji, Kodak, Sanyo.

Jim

[Zero1]

Originally Posted by Xorro2k

Hi, I have recently upgraded from the A40 to the A710 IS and have experienced everything mentioned in the first post with regard to battery life.

I was quite pleased that the A710 only takes 2 batteries, as it meant I would get twice as much use out of the 2 sets of 4 I currently have, however I have been astonished at the speed in which the low battery indicator comes on.

For instance I took around 20 photos in approx 20 mins (some with flash) and the battery indicator came on.

I am using Hahnel 1700mah and Uniross 2000mah, both are NiMh.

I am currently looking for some 2700mah branded cells, but would be interested in hearing more from other users.

P.S. The camera came with 4 alkaline batts which lasted about 3 times longer than the rechargables.

I upgraded to an A710 from an A40 as well and noticed the opposite. The alkaline batteries that came with the camera lasted 20 min before the low bat light came on and another 10 min before it shut down. I took around 10 flash pics and 20 non-flash with LCD on and IS on. My Energizer 2500 however is still going after 3 days of use, around 200 pics with half of them with flash.

[SuperBet]

Hey! Check this!

http://www.usa.canon.com/consumer/co...=2111&id=28799

[vivona]

Originally Posted by SuperBet

Hey! Check this!

http://www.usa.canon.com/consumer/co...=2111&id=28799

Hey, check this:

Originally Posted by vivona

I am NOT referring to the recall of a small number of A540 and A530 cameras that have a incorrectly formed battery cover spring. My camera is not included in that recall and the battery cover spring is formed okay.

[vivona]

Here is an update.

I got a set of Energizer 2500mAh cells and put them in 12 days ago. I got 280 pictures, most with the flash and all with the LCD on before the low battery indicator came on. That is a substantial improvement over my other batteries. It gets back to the variability between brands of batteries as illustrated in the voltage graphs at http://www.users.on.net/~mhains/Reviews.html . If your camera cut off at .9V like the tests show, then you would get the expected runtime. If it cuts off at a higher voltage, say 1.1V, then it would cut off very early for many of the cells tested. I haven't located the correct plug to test the A540 with an external power supply and only recently found the polarity of the connector (it isn't marked on the camera, but is center-positive). I am betting that the A540, and the other two-battery cameras in the A series, cut off around 1V or so.

I just got my Sanyo eneloops and will begin their test soon. I expect them to perform very well because of their higher than normal voltage graph.

By the way, Robukincan, the A630 gets better battery life because it uses 4 cells and that allows the current draw to be about half of a 2-cell camera, so the voltage drop isn't as fast.