battery power determinants in digital cameras

[Nodda Duma]

Instead of torque, think of it in terms of power: The voltage multiplied by the current.

 

[Chan Tran]

I think you have accomplished the most difficult task and that of connecting wires to the battery compartment so you can power it with an external source. If I have done that I would certainly make an experiment to see how low the voltage gets when the camera is drawing the most current. I would try that with 2 new batteries, 2 used batteries and 3 used batteries and perhaps even with a solid regulated 3V power supply and also measuring the current. With those information collected I would then determine that problem.

 

[David Lyga]

Thank you Nodda for the clarification of my analogy.

Chan Tran: Surprisingly, the difficulty was more formidable than anticipated. What I did was this, (after spending hours, over weeks, pondering the issue): I bought a very cheap dollar store packet of plastic highlighter pens that were slightly less than the diameter of an AA battery. I then removed the ink pod from the rear, and, now empty and hollow, I cut two cylinders each to a bit less than the length of an AA battery. I then put a screw with nut at the bottom of the cylinder (in order to be able to touch the positive and negative battery terminals) and attached wires, securely, by tightening each nut. The nut was a bit wider than the cylinder, so it would stay just below the cylinder. The wires were drawn through the respective cylinders and could easily exit the camera's battery compartment easily, because on the Nikon Cool Pix 3200 there is a tiny opening where the battery compartment cover meets the compartment. (Otherwise, I would have had to drill a tiny hole in an area that was not encumbered with electronics.) Thus I was able to draw the wires out of the camera body, and, because there was no metal on top of the cylinder, the normal metal bridging the two batteries that was on the bottom of the battery cover, mattered not and shorted out nothing. The battery compartment closed, but just barely, as I had wanted, making certain that each cylinder, and its respective screw and nut, would remain touching the terminals.

I had bought a three-AA cell battery holder that I was able to insert the batteries to, in series, thus giving 4.5 volts. Thus, my experiment was complete, excect for one minor thing: the damn thing did not supply enough power to the camera!!!!

Chan Tran: I did test the three-cell configuration beforehand, using messy tape and persistence, before I delved into the project. But, as with my finished project, the camera still fired up. What I failed to do was to follow through with an actual exposure and see it saved to my SD card, I had thought that the 'firing up' of the camera would be sufficient, my guarantee that all would be well. I learned something here: David Lyga is capable of high stupidity. - David Lyga

 

[Chan Tran]

Thank you Nodda for the clarification of my analogy.

Chan Tran: Surprisingly, the difficulty was more formidable than anticipated. What I did was this, (after spending hours, over weeks, pondering the issue): I bought a very cheap dollar store packet of plastic highlighter pens that were slightly less than the diameter of an AA battery. I then removed the ink pod from the rear, and, now empty and hollow, I cut two cylinders each to a bit less than the length of an AA battery. I then put a screw with nut at the bottom of the cylinder (in order to be able to touch the positive and negative battery terminals) and attached wires, securely, by tightening each nut. The nut was a bit wider than the cylinder, so it would stay just below the cylinder. The wires were drawn through the respective cylinders and could easily exit the camera's battery compartment easily, because on the Nikon Cool Pix 3200 there is a tiny opening where the battery compartment cover meets the compartment. (Otherwise, I would have had to drill a tiny hole in an area that was not encumbered with electronics.) Thus I was able to draw the wires out of the camera body, and, because there was no metal on top of the cylinder, the normal metal bridging the two batteries that was on the bottom of the battery cover, mattered not and shorted out nothing. The battery compartment closed, but just barely, as I had wanted, making certain that each cylinder, and its respective screw and nut, would remain touching the terminals.

I had bought a three-AA cell battery holder that I was able to insert the batteries to, in series, thus giving 4.5 volts. Thus, my experiment was complete, excect for one minor thing: the damn thing did not supply enough power to the camera!!!!

Chan Tran: I did test the three-cell configuration beforehand, using messy tape and persistence, before I delved into the project. But, as with my finished project, the camera still fired up. What I failed to do was to follow through with an actual exposure and see it saved to my SD card, I had thought that the 'firing up' of the camera would be sufficient, my guarantee that all would be well. I learned something here: David Lyga is capable of high stupidity. - David Lyga

I sure wish to meet you some day.

 

[bdial]

This pic may help a little;

 

[DWThomas]

This pic may help a little;

I love it!

 

[Paul Howell]

I have a Pentax K2000, one of the instruction books, it came with 2, stated not to use used batterers, don't mix used and new batteries, not to mix brands and remove the batteries if the camera was going to be ideal for more than a couple of weeks. Oddly enough Minolta gave the same directions for the 12 batteries used to power the 12 AA motor drive for the A9000. There is an old saying, Penney Wise is Pound Foolish. Saving a few dollars can ruin your camera.

 

[Jim Jones]

I was an electronics repairman for most of my working years, and still don't know as much as I should about batteries. Most of the advice given by others is good. Strong batteries in series with a weak battery can apply reverse voltage to the weak one. In the case of the old Ni-Cad batteries, this ruined the weak battery. Sometimes a quite powerful charging current of the correct polarity would bring it back to limited life. See, I used to try stupid things, too. Eneloops are all the AA batteries I use in electronic equipment. So far the lower voltage as compared to fresh alkaline batteries hasn't caused problems. Just now four AA Eneloops fresh from the charger measured between 1.427 and 1.455 volts with a digital multi-meter. As others have noted, this kind of meter doesn't place a proper load on the batteries. That voltage will drop down a bit, and then be stable for quite a while. A couple on Eneloops that haven't been recharged for a year or so measure about 1.28 V.For anyone who uses a lot of AA batteries, rechargeable Ni-MH are cost effective. Eneloops may be the preferred brand for many of us. There are cheap batteries of all types, often from China, that are not reliable. The Nikon DSLRs that I use now require a proprietary rechargeable battery. I can get maybe four or five hundred shots over a few hours of sports photographs on one charge. After almost 8 years I haven't had a Nikon battery loose noticeable efficiency.

 

[David Lyga]

I sure wish to meet you some day.

It will be an experience that you will never forget. But ... that experience just might be not what you had expected. Still I would like to meet anyone who dares such. I do not bite. - David Lyga

 

[David Lyga]

After the Samsung disaster on one of its laptops (or phones) I tend to heed these advisory mandates. - David Lyga

 

[David Lyga]

I was an electronics repairman for most of my working years, and still don't know as much as I should about batteries. Most of the advice given by others is good. Strong batteries in series with a weak battery can apply reverse voltage to the weak one. In the case of the old Ni-Cad batteries, this ruined the weak battery. Sometimes a quite powerful charging current of the correct polarity would bring it back to limited life. See, I used to try stupid things, too. Eneloops are all the AA batteries I use in electronic equipment. So far the lower voltage as compared to fresh alkaline batteries hasn't caused problems. Just now four AA Eneloops fresh from the charger measured between 1.427 and 1.455 volts with a digital multi-meter. As others have noted, this kind of meter doesn't place a proper load on the batteries. That voltage will drop down a bit, and then be stable for quite a while. A couple on Eneloops that haven't been recharged for a year or so measure about 1.28 V.For anyone who uses a lot of AA batteries, rechargeable Ni-MH are cost effective. Eneloops may be the preferred brand for many of us. There are cheap batteries of all types, often from China, that are not reliable. The Nikon DSLRs that I use now require a proprietary rechargeable battery. I can get maybe four or five hundred shots over a few hours of sports photographs on one charge. After almost 8 years I haven't had a Nikon battery loose noticeable efficiency.

Revered names do have their place within our confusing world. Developing brand names are done for good reason. - David Lyga

 

[David Lyga]

I have a Pentax K2000, one of the instruction books, it came with 2, stated not to use used batterers, don't mix used and new batteries, not to mix brands and remove the batteries if the camera was going to be ideal for more than a couple of weeks. Oddly enough Minolta gave the same directions for the 12 batteries used to power the 12 AA motor drive for the A9000. There is an old saying, Penney Wise is Pound Foolish. Saving a few dollars can ruin your camera.

Yes, to you and others: I do appreciate being thwarted from my 50s and 60s battery mentality. My stupidity has limits. - David Lyga

 

[Chan Tran]

I do check battery with no load. For alkaline if the voltage is less than 1.5V it's considered dead. For NiMH if it's less than 1.25V it's considered dead.

 

[David Lyga]

That is some concept that I fail to understand. If 1.25 volts is sufficient, why is 1.49 volts insufficient? - David Lyga

 

[Chan Tran]

That is some concept that I fail to understand. If 1.25 volts is sufficient, why is 1.49 volts insufficient? - David Lyga

Because I measure them without a load (only with the DMM which draw almost no current). Under typical load the alkaline that measure 1.49V would drop to lower than 1.2V I would expect. A NiMH which measured 1.25V with no load would maintain about 1.2V under load. In fact I am confident that your CP3200 would work if the voltage of the 2 batteries is 2.4V or more.

 

[David Lyga]

OK, then it is the 'ability to pull power' that determines sufficiency with 'digital writing'. I think I finally am getting this. To me, it is simply 'torque'. That is how I remember best. - David Lyga

 

[MattKing]

David:
If you shuffle your shoes on a carpet and then reach out to touch something, there is a good chance you will feel a shock. That is referred to as static electricity, and it can easily involve a charge (essentially pressure) of 25,000 volts!
That little shock isn't particularly dangerous and damaging, because the amperage (volume, not pressure) of electricity is so small.
Those testers measure voltage only, whereas the capacity of a battery is actually related to its ability to supply amperage at a sufficient voltage.
Those testers aren't really capable of responding to a transient spark like static electricity, but if they were, they would reed something like 25,000 volts!

 

[Chan Tran]

OK, then it is the 'ability to pull power' that determines sufficiency with 'digital writing'. I think I finally am getting this. To me, it is simply 'torque'. That is how I remember best. - David Lyga

That is why when you have your batteries outside of the camera I would want to check their voltage when the camera is working.

 

[David Lyga]

"when the camera is working" I interpret to mean "as the drain is happening". I think I do understand. - David Lyga

 

[David Lyga]

David:
If you shuffle your shoes on a carpet and then reach out to touch something, there is a good chance you will feel a shock. That is referred to as static electricity, and it can easily involve a charge (essentially pressure) of 25,000 volts!
That little shock isn't particularly dangerous and damaging, because the amperage (volume, not pressure) of electricity is so small.
Those testers measure voltage only, whereas the capacity of a battery is actually related to its ability to supply amperage at a sufficient voltage.
Those testers aren't really capable of responding to a transient spark like static electricity, but if they were, they would reed something like 25,000 volts!

Thank you Matt: you people try so hard with me and I appreciate it. There is more to life than a battery tester, that is for sure. Dark energy pervades. - David Lyga

 

[Chan Tran]

"when the camera is working" I interpret to mean "as the drain is happening". I think I do understand. - David Lyga

Yes at the time the camera is taking the picture and writing the card. The voltage would be up and down but I would want to find out at which time the voltage is at its lowest and at what voltage. Since your camera would work with 2 new but not 3 used I think with the 3 used one although the voltage is higher than 3V when the camera is off it would be lower than 2.4V when it stopped working.

 

[David Lyga]

...essentially, because, during the actual drain (i.e, 'writing'), the pull on the battery power is so intense. (This is analogous to a healthy eighty year-old person being asked to run fast, but for only 100 meters. He quickly exhausts himself.) You have explained well and I thank you. - David Lyga

 

[Chan Tran]

Yup! you got it David. That's why with nominal voltage of 1.2V for the NiCad and NiMH which is lower than the 1.5V alkaline they recycle the flash faster than the alkaline can. During the initial charging of the flash capacitor the batteries would be under an almost short circuit situation. Many of the old flashes designed counting on the fact that the alkaline batteries voltage would drop so low in this condition and wouldn't put out too much current and when I used the NiCad in the Vivitar 202 with NiCad (NiCad actually performs a bit better than NiMH in this situation) it recycled so fast and smoked the flash. The flash still worked after that though.

 

[Alan Edward Klein]

Lithiums are great in cold weather as they hold their charge and don't fade.

 

[blockend]

If you shuffle your shoes on a carpet and then reach out to touch something, there is a good chance you will feel a shock

That brings back memories of working in a building with carpets of man made fibre, and a pair of crepe soled desert boots. Opening my car door at the end of the day would produce a shock that was painful enough to be debilitating, at least temporarily. The crack made by the charge was audible and the flash easily visible, especially at night. Changing shoes reduced the effects considerably. All off topic.

I'm surprised to hear any working digital cameras still use AA cells. My experience of renewing batteries suggests the host device expires as soon as I've purchased them. A phenomenon that's new to me but research suggests is far from uncommon, is battery swelling. I first noticed this on a Fuji X-Pro1 in which I falsely assumed the release spring had weakened. It turned out the battery had swollen to an interference fit. As I had four used in rotation, two of which had grown sufficiently to be unusable and the camera wasn't in constant use, the charge cycle of each battery wasn't great. The batteries were Chinese knock-offs but it seems the Fuji originals are also prone to cell enlargement.