battery power determinants in digital cameras

At least to me, this posting asks a very interesting question, the answer of which might confound my limited knowledge of electronics. This requires the help from someone with an in-depth knowledge of both electronics and digital technology.

I have a few, very small cheap digital cameras which suit my needs well. When I acquired these, I made certain that each took two AA batteries because I did not want to bother with chargers for such limited use. I knew before I had bought these, as most will know, that AA alkalines do not last too long in these cameras, maybe about 40 shots per set. (I accept that and know that rechargeable batteries are available.) When the batteries are 'deficient' a screen warning shows, stating that 'batteries are exhausted'. Out of curiosity, I have always tested these 'exhausted' AA batteries on a battery tester and compared the readings with those from new alkalines. Amazingly, the reading difference was very slight and I could not really understand why the camera no longer saw the 'used' batteries as being sufficiently powerful.

Being ever frugal, I got thinking. If two 'used' batteries were insufficient, why not use THREE 'used' alkalines to bring back the power to proper strength and not have to segregate such 'used' batteries when they are still very good? (I certainly had enough used batteries lying around, as I do not generally discard such but use them for other things such as radios and flashlights.)

I bought a cheap three AA cell battery holder which would provide a 4.5 volt 'in series' output into the camera (NIKON CoolPix 3200). I figured a way to attach the camera's battery terminals correctly and securely, with wires coming out of the camera into this three-cell holder. (I know that this sounds nuts ... but I am a rather nutty person; besides, I wanted to prove how smart I was in doing this 'waste avoidance'.) However, before I tested this voltage in the camera, I wanted to verify the power output, in comparison with the output from two fresh alkaline batteries. Again, I used a battery checker and found the output from the two fresh batteries to be slightly less than the output from the three slightly used batteries. This was as predicted. But to verify, I tested both battery sets with a 6 volt lantern bulb and, again, found the output of the three used batteries to cause the bulb to be a bit brighter than the output did from the two fresh akalines. This was what I had predicted, as the 'used' batteries had registered as almost new on the battery checker. I thoroughly checked all wiring and was ready to use the 4.5 voltage in the camera. In advance, I knew that this was risky: Would the 4.5 volts blow out the camera's circuitry?

The 4.5 volts proved, initially, to fire up the camera, but when I attempted to take a picture, the screen 'batteries exhausted' showed up. Of course, I was utterly amazed, because this three-set arrangement had tested a bit stronger than the two fresh alkalines. Miffed, I removed the three cell wiring from the camera and put into the camera the two fresh cells. It worked perfectly. I tested again and again and found the three 'used' cell arrangement to always show 'exhausted'; the two fresh cells worked perfectly despite the fact that the three cell arrangement always registered with a bit more power on traditional battery meters and bulbs.

With my limited knowledge of both electronics and digital technology, I am truly stumped. I had always thought that battery power was indicated in one way only: by testing on either a battery checker or with an incandescent bulb. Apparently, there is a certain 'power' that digital needs from its battery source that does not register on traditional meters. Apparently, fresh alkalines have this 'dark energy!!!' but used ones no longer have this dark power. My tests were done with complete accuracy but have been proven to show that there is 'some' power that digital cameras need which remains inscrutable and arcane (if not downright insane). Can anyone address this dilemma? - David Lyga

I'm typing on a phone so I'll keep it short. The camera measures the voltage while current is drawn from the battery. Drawing current causes the voltage to drop. If the voltage drops too much, the battery is exausted. A voltmeter draws much less current than the camera. So the voltmeter might measure close to 1.5 V while the camera measure much less. Don't connect 4.5 V to a 3 V camera. As you've noticed it doesn't help and it might damage the camera electronics.

As spijker states, the real meteic is power.


Use Lithiums. They will last longer.

IMHO, you're chasing false economy here David. For one thing mixing partially used batteries, or even worse, mixing fresh ones and used ones is an excellent way to induce leakage. This happens because the batteries with more charge are basically "trying" to charge the weaker ones when they're in a circuit. The charging creates pressures the battery case isn't designed to accommodate.
However, if you're really determined to try and squeeze more juice out, a better approach might be to use 4 batteries, with a pair in parallel (connected negative to negative) then the two pairs in series, assuming you're working with a device that needs 3 volts.
That gives you the correct voltage and gets you more energy capacity. Note, this is a theoretical suggestion, not something I've tried, or would likely try.
I put my "almost worn out" batteries in my clocks that use a single battery. The quartz clock movements can go for a long time on very little power, and there are no leakage issues since they just use a single battery.

Though expensive to buy initially, there are now rechargeables available that retain their charge for a year or more, a few sets of those and you might not need to buy batteries ever again. The lithium AA's work well too, they have a very long shelf life, perform better in cold weather than alkalines, and last a very long time in high-demand circuits like cameras. They are pricey too, but will easily outlast 4 or perhaps 5 sets of standard AA's. They also weigh less. The major downside is that they produce slightly more voltage under load than alkaline batteries, and some devices can't tolerate them, though the only camera I know of where they are specifically not recommended is the Hasselblad ELX.

Sorta along the same lines, I have two Canon digitals which use the same proprietary LI battery. The Canon Powershot G9 is a smallish viewfinder type and the Canon Rebel XTI is an older SLR. When I place the battery in the G9 it shows a full charge. Remove and put the battery into the Rebel and it shows 3/4 charge. Thinking the Rebel consumes a lot more power even when at rest, between actuations.

spijker said:

I'm typing on a phone so I'll keep it short. The camera measures the voltage while current is drawn from the battery. Drawing current causes the voltage to drop. If the voltage drops too much, the battery is exausted. A voltmeter draws much less current than the camera. So the voltmeter might measure close to 1.5 V while the camera measure much less. Don't connect 4.5 V to a 3 V camera. As you've noticed it doesn't help and it might damage the camera electronics.

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As a kid, I used to hook up batteries that had more power than the device that they were attached to required. It was great fun watching certain games run faster, sound higher in pitch, etc, but ultimately I fried them all as the circuits in them could not handle the extra voltage. There's a reason they are specified to a specific voltage.

spijker said:

I'm typing on a phone so I'll keep it short. The camera measures the voltage while current is drawn from the battery. Drawing current causes the voltage to drop. If the voltage drops too much, the battery is exausted. A voltmeter draws much less current than the camera. So the voltmeter might measure close to 1.5 V while the camera measure much less. Don't connect 4.5 V to a 3 V camera. As you've noticed it doesn't help and it might damage the camera electronics.

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You know, I get the idea that you are presenting an analogy: that of 'torque' from an automobile engine. I am beginning to see the light here, but I will read others' comments. Thank you. - David Lyga

Doing what you attempted is a good way to have a battery explode. Simply put, what you're measuring to see if a battery is good or not, is the voltage. What the camera also needs to run (outside of the voltage), is the amperage. Voltage can be a decent indicator of the amount of power left in a battery, because as the amount of amps a battery outputs drops, so does its volts. But running three batteries in series to up the voltage doesn't do anything to up the amperage. That's why it's still not working. What's worse, is because you're now overdrawing these dying batteries (and probably mixing and matching batteries at various levels of drain), you're greatly increasing the risk of having one explode on you. Like a literal, loud, spew battery acid everywhere type of explosion. And since I'm assuming you're not enclosing these batteries in something to protect you, your running the risk of serious personal injury. Also, as previously mentioned, you run the risk of destroying the camera by running too high of a voltage through it (though at only around 1.5v higher, I don't think that's likely the issue).

If you want longer lasting batteries, get some lithium batteries. Energizer makes what they call an "Ultimate Lithium". They run at a slightly higher voltage than alkaline, but should still be safe to use in your camera. They also have a steadier power curve, which means they don't drop off and die nearly as quickly. As an added bonus, they don't leak like alkalines will, and they take to being stored for long periods of time much better.

I could get a lot more technical, but I don't think that would help. That's pretty much as simply as I can figure to put it. Bottom line, what you attempted was dangerous and should not be repeated.

RattyMouse said:

As a kid, I used to hook up batteries that had more power than the device that they were attached to required. It was great fun watching certain games run faster, sound higher in pitch, etc, but ultimately I fried them all as the circuits in them could not handle the extra voltage. There's a reason they are specified to a specific voltage.

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You know, in fairness to me, I once had a Canon S2 IS which took four AA batteries. On this camera there was a DC input which stated 7.4 volts, so, using this general 'voltage roughness' to project onto other digital cameras, I had 'determined' that my attempt with 4.5 volts would not upset the apple cart. Still, even with the 'greater' power, the 'torque' from the three slightly used batteries was not sufficient to 'tell' the camera that it had enough power.

You have to understand that, at 68, 'batteries' hold an entirely different meaning for me, as the only 'new' battery development during my younger years was 'alkaline' (essentially, 'better' zinc and carbon batteries but not really otherwise 'different', as Lithiums are). Apparently, with alkalines there is an initial surge that the camera wants (needs?) in order to fully process the image. This surge is, I guess, quickly lost. - David Lyga

jim10219 said:

Doing what you attempted is a good way to have a battery explode. Simply put, what you're measuring to see if a battery is good or not, is the voltage. What the camera also needs to run (outside of the voltage), is the amperage. Voltage can be a decent indicator of the amount of power left in a battery, because as the amount of amps a battery outputs drops, so does its volts. But running three batteries in series to up the voltage doesn't do anything to up the amperage. That's why it's still not working. What's worse, is because you're now overdrawing these dying batteries (and probably mixing and matching batteries at various levels of drain), you're greatly increasing the risk of having one explode on you. Like a literal, loud, spew battery acid everywhere type of explosion. And since I'm assuming you're not enclosing these batteries in something to protect you, your running the risk of serious personal injury. Also, as previously mentioned, you run the risk of destroying the camera by running too high of a voltage through it (though at only around 1.5v higher, I don't think that's likely the issue).

If you want longer lasting batteries, get some lithium batteries. Energizer makes what they call an "Ultimate Lithium". They run at a slightly higher voltage than alkaline, but should still be safe to use in your camera. They also have a steadier power curve, which means they don't drop off and die nearly as quickly. As an added bonus, they don't leak like alkalines will, and they take to being stored for long periods of time much better.

I could get a lot more technical, but I don't think that would help. That's pretty much as simply as I can figure to put it. Bottom line, what you attempted was dangerous and should not be repeated.

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NO, the three batteries had just about the same strength, through the same usage, but, no, the casing was open, thus, as you said, I might have been vulnerable. I will cease this operation, but fail to see how an explosion could have manifested. Still, I heed well when I am frightened. - David Lyga

David,
Since you already made your 3 cell battery pack that is outside of the camera I would suggest you to build a 2 cell pack. Put the 3 used batteries in the 3 cell pack and 2 fresh batteries in the 2 cell pack. Connect the voltmeter to the pack (which is possible because you have the pack external) and measure the voltage especially when you try to take a picture. Do the same for both pack and see if the 2 fresh cells would produce higher voltage than the 3 used cells. If so your battery tester doesn't put sufficient load on the battery for testing.
I wouldn't worry too much about alkaline batteries explode if you use them under you supervision and not use them unattended.

Enelopes.....probably the best rechargeable battery out there. These are a real simple way to reduce battery consumption.

David,
I think it's less expensive if you build a 2 cell for D batteries. They cost typically 2.5 times that of AA but last about 5 times that of AA.

Chan Tran said:

David,
Since you already made your 3 cell battery pack that is outside of the camera I would suggest you to build a 2 cell pack. Put the 3 used batteries in the 3 cell pack and 2 fresh batteries in the 2 cell pack. Connect the voltmeter to the pack (which is possible because you have the pack external) and measure the voltage especially when you try to take a picture. Do the same for both pack and see if the 2 fresh cells would produce higher voltage than the 3 used cells. If so your battery tester doesn't put sufficient load on the battery for testing.
I wouldn't worry too much about alkaline batteries explode if you use them under you supervision and not use them unattended.

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I used to not worry about alkaline batteries exploding, because I had never seen or heard of one doing it. Leaking, sure. But exploding? Then about three months ago my girlfriend was powering a small electric motor that ran off 8 AA batteries (a geared linear actuator for a costume she was making). She didn't have 8 new AA batteries, so she grabbed 4 new and 4 older, but still usable AA's that still had plenty of charge. After about 30 seconds of use, one of the batteries blew up and shattered the plastic battery holder and leaked battery fluid all over the inside of the case. She was unharmed, but scared. So up until then I always thought alkalines were relatively safe. And I still believe they're still a lot safer than something like a Lithium Ion! But my illusion of their complete safety cracked with that battery case.

Anyway, your idea about an external battery back is still a good one. I'd look to either run 4 AA's (in a series/parallel configuration for the same voltage at double the available power), or a larger cell (like C or D), as you mentioned. Though, any of those requires you to keep extra batteries outside of the camera, which will make it heavier and more cumbersome. So I still default back to my Lithium battery idea (not lithium ion rechargeable, which is a different technology), just because it's the easiest solution (though would be more costly).

jim10219 said:

I used to not worry about alkaline batteries exploding, because I had never seen or heard of one doing it. Leaking, sure. But exploding? Then about three months ago my girlfriend was powering a small electric motor that ran off 8 AA batteries (a geared linear actuator for a costume she was making). She didn't have 8 new AA batteries, so she grabbed 4 new and 4 older, but still usable AA's that still had plenty of charge. After about 30 seconds of use, one of the batteries blew up and shattered the plastic battery holder and leaked battery fluid all over the inside of the case. She was unharmed, but scared. So up until then I always thought alkalines were relatively safe. And I still believe they're still a lot safer than something like a Lithium Ion! But my illusion of their complete safety cracked with that battery case.

Anyway, your idea about an external battery back is still a good one. I'd look to either run 4 AA's (in a series/parallel configuration for the same voltage at double the available power), or a larger cell (like C or D), as you mentioned. Though, any of those requires you to keep extra batteries outside of the camera, which will make it heavier and more cumbersome. So I still default back to my Lithium battery idea (not lithium ion rechargeable, which is a different technology), just because it's the easiest solution (though would be more costly).

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Jim,, your comments are MORE than appropriate and I thank you for this information. Am I to believe that parallel alignment is not dangerous, as voltage is not increased, simply buoyed-up for a longer lasting situation? Yes, two D cells should work wonders, in series, but, again, as you infer, for what real, lasting purpose other than to prove a (bulky) point? AA Alkalines are often on sale, and really cheap, AND they are invariably half the cost of those D cells at the same sale. I like to draw blood out of stone, but this time I am running scared with your girlfriend's experience (I wish these dangers were better known). - David Lyga

Chan Tran said:

David,
Since you already made your 3 cell battery pack that is outside of the camera I would suggest you to build a 2 cell pack. Put the 3 used batteries in the 3 cell pack and 2 fresh batteries in the 2 cell pack. Connect the voltmeter to the pack (which is possible because you have the pack external) and measure the voltage especially when you try to take a picture. Do the same for both pack and see if the 2 fresh cells would produce higher voltage than the 3 used cells. If so your battery tester doesn't put sufficient load on the battery for testing.
I wouldn't worry too much about alkaline batteries explode if you use them under you supervision and not use them unattended.

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I am now a bit afraid of such 'gentle' batteries. In my whole life I have never had a battery explode, but that does not mean that I think I am right here. Thank you all. - David Lyga

RattyMouse said:

Enelopes.....probably the best rechargeable battery out there. These are a real simple way to reduce battery consumption.

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How long do enelopes hold their charge?

Alan Edward Klein said:

How long do enelopes hold their charge?

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It depends on what they are powering. All I know is that they are the industry leading rechargeable battery.

David Lyga said:

Jim,, your comments are MORE than appropriate and I thank you for this information. Am I to believe that parallel alignment is not dangerous, as voltage is not increased, simply buoyed-up for a longer lasting situation? Yes, two D cells should work wonders, in series, but, again, as you infer, for what real, lasting purpose other than to prove a (bulky) point? AA Alkalines are often on sale, and really cheap, AND they are invariably half the cost of those D cells at the same sale. I like to draw blood out of stone, but this time I am running scared with your girlfriend's experience (I wish these dangers were better known). - David Lyga

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I would try to avoid using batteries in parallel if I can. The reason is simply if the 2 batteries in parallel don't have the same voltage the current will flow from the high voltage one to the lower voltage one.

Well I never got too deeply into it but I suspect there are significant transient loads during various phases of a digicam's operation -- as with those lens assemblies that whir and turn and extend via motorized mechanics. Writing to memory cards is another area where power consumption likely jumps up. The color LCD display is another battery hog. All that stuff has gotten more efficient than it once was, but nothing is free.

It's likely the "battery tester" David uses may have some sort of load built in -- but then the question becomes what is that load. I would point out that the rechargeables I'm aware of do not normally put out the same voltage as alkaline cells to begin with, usually about 1.25 although some of the lithium units are 3.-something so maybe they could replace two alkaline cells in series. Some cameras -- my ancient and no longer properly functioning Canon A80 was one -- are designed to use NiMh cells or alkalines.

The thought passed through what's left of my mind that the battery sensing circuit might look for a certain operating voltage and flag too much as well as too little. But the software geeks being in a hurry they just called the 'ExhaustedBattery' routine in that event, as "it uses two batteries, the voltage can never be high." One never can be sure what evolutionary process a chunk of software has been through. (BTDT )

Those special super-duper rechargeables are Eneloop batteries - note spelling. They are supposed to be very effective at minimizing self discharge, but again, they only put out about 1.2 volts.

My random thoughts ...

DWThomas said:

Those special super-duper rechargeables are Eneloop batteries - note spelling. They are supposed to be very effective at minimizing self discharge, but again, they only put out about 1.2 volts.

My random thoughts ...

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Thank you for correcting my mistake.

David Lyga said:

Jim,, your comments are MORE than appropriate and I thank you for this information. Am I to believe that parallel alignment is not dangerous, as voltage is not increased, simply buoyed-up for a longer lasting situation? Yes, two D cells should work wonders, in series, but, again, as you infer, for what real, lasting purpose other than to prove a (bulky) point? AA Alkalines are often on sale, and really cheap, AND they are invariably half the cost of those D cells at the same sale. I like to draw blood out of stone, but this time I am running scared with your girlfriend's experience (I wish these dangers were better known). - David Lyga

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I shouldn't have mentioned the parallel/series idea. It's better than running your three batteries in series to extend the life of the old batteries, but still not a good idea. Like Chan stated, if one of the batteries is weaker than the others, it could cause a back current on that battery and run another explosion/leak risk. Basically any modification from the original design is going to have it's drawbacks. The camera was made one way. For better or worse, that's the way it's going to work best. Anything else will likely introduce more problems than it solves.

Really, your best, safest, and easiest option is to just start using the lithium AA batteries I keep suggesting. No modifications required. They're regular AA batteries with a different chemistry inside, and can be found at most places where you buy regular AA batteries. They'll last a whole lot longer (probably about 4x's longer) than the Alkalines you've been using, because unlike an Alkaline, they don't steadily loose voltage over their lifespans, rendering it useless long before the battery is actually dead. They stay around 1.6-1.4 volts pretty much until the minute they die. They are specifically designed for high drain devices that require a higher voltage to maintain operation, just like your digital camera. I don't use them often due to their increased cost over regular batteries and the fact that in most devices, they don't offer any real benefit (other than reduced chance of leakage). However, there are a few devices where they are definitely worth while, like digital cameras or anything else that drains regular batteries really quickly. Using them in something like a TV remote, which typically have a very low drain and high tolerance for low voltages, would be a waste of money.

The Enloops are supposed to retain 85% of their charge for a year. They have good capacity too, 2550 mili-amp hours which puts them on par with premium alkalines.
One side-effect advantage of the lithium AA's is that they are a bit lighter than alkaline AA's, not a big deal on a device that uses 2, but noticeable on my F3 that uses 8.
Lot's of info about AA'a here; https://en.wikipedia.org/wiki/AA_battery

DWThomas said:

Well I never got too deeply into it but I suspect there are significant transient loads during various phases of a digicam's operation -- as with those lens assemblies that whir and turn and extend via motorized mechanics. Writing to memory cards is another area where power consumption likely jumps up. The color LCD display is another battery hog. All that stuff has gotten more efficient than it once was, but nothing is free.

It's likely the "battery tester" David uses may have some sort of load built in -- but then the question becomes what is that load. I would point out that the rechargeables I'm aware of do not normally put out the same voltage as alkaline cells to begin with, usually about 1.25 although some of the lithium units are 3.-something so maybe they could replace two alkaline cells in series. Some cameras -- my ancient and no longer properly functioning Canon A80 was one -- are designed to use NiMh cells or alkalines.

The thought passed through what's left of my mind that the battery sensing circuit might look for a certain operating voltage and flag too much as well as too little. But the software geeks being in a hurry they just called the 'ExhaustedBattery' routine in that event, as "it uses two batteries, the voltage can never be high." One never can be sure what evolutionary process a chunk of software has been through. (BTDT )

Those special super-duper rechargeables are Eneloop batteries - note spelling. They are supposed to be very effective at minimizing self discharge, but again, they only put out about 1.2 volts.

My random thoughts ...

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You know, I 'study' these problems in a strictly utilitarian sense, l(ike I used to study the grooves on my 45s and 78s when I was a child), noticing that there were wide grooves and narrow groves. As a result, I feel a need to qualify what you say in that I honestly feel that the whirs and motors are NOT the problem, but, rather, 'writing' is the new concept. For some reason, 'torque' is needed for writing to the card. The battery must be more than of adequate voltage. Conceptually, (and NOT technically, where I fall by the wayside) a type of surge is needed which only NEW alkalines can deliver. This concept is new to me. - David Lyga

jim10219 said:

Really, your best, safest, and easiest option is to just start using the lithium AA batteries I keep suggesting. No modifications required. They're regular AA batteries with a different chemistry inside, and can be found at most places where you buy regular AA batteries. They'll last a whole lot longer (probably about 4x's longer) than the Alkalines you've been using, because unlike an Alkaline, they don't steadily loose voltage over their lifespans, rendering it useless long before the battery is actually dead. They stay around 1.6-1.4 volts pretty much until the minute they die. They are specifically designed for high drain devices that require a higher voltage to maintain operation, just like your digital camera. .

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You know, you just might have talked me into doing something, jim, in that it takes literally decades for me to recognize new technology. For example, my FIRST mobile phone was acquired in 2009 and it is the same filpfone design I have now!!! My first credit card was acquired in 2016 (I had no need before then!!!) And (please do not keep me up laughing all night about this): Until about one month ago I had been using, solely, library computers. Last month I got sick of that restriction and sent away for a refurbished Samsung Chromebook for a total of $81, including postage. I did not know if I would be able to figure out how to operate it, but I liked it so much I bought an identical one the following week. I cannot tear myself away from this 'machine', (although logging onto banks and emails requires that I be in a secure WiFi location with password).. Yes, I still use library computers that are hard-wired, but the opening up of my mind is turning out to be something very enriching.

The responses to this topic have been far from useless and I take them all to heart. Fear is a funny thing: if you told me that in two weeks I would have to be at a certain address in Timbuktu, alone, I would not wince. If you told me that I had to drive a bus for a few miles in Philadelphia, I would faint from fright. - David Lyga