NiMh battery problems!

[spoolin01]

Poor execution or not, all three of my A570 cameras work great, shoot great, great features, great optics for a P&S and work fine shot after shot for a full day of diving with the Eneloop/Duracell Pre-charged batteries.

I am not hard headed, I just go with what works.

N

Well, so those hours of troubleshooting did pay off . ... and there's always room for those older NiMHs in the drawer with the NiCds, alkalines, 10 sizes of button batteries (in three chemistries), proprietary batteries with no more purpose, and chargers that all work at the same few voltages but don't interchange plugs or match current.

 

[Maddog59]

I'm not talking about defective batteries. When we talk about electronically matched cells we're talking about the load capacity of the cell in Mah and as twenty cells will have twenty different load ratings it is most important that the cells are matched in operating sets where all the cells in the pack are as close to each other as possible + or - 3% is the ideal.
The best way to do this is with a computerised load rating tester, but as these are expensive and time consuming to use the best we can do as a consumer is to use a charger which will measure and record the capacity of each cell as it is charged.



Maddog59
Canon G10, Patima Housing, 2 x Inon Z240/4 Strobes electronically wired,Maha C 9000 charger

 

[spoolin01]

If you're not talking about defective batteries then I think this capacity-matching thing is nonsense. Does your camera work with matched 2500mAh cells? Matched 2250mAh cells? Matched 2000mAh cells? What do you think the camera sees when you pair a 2500 with a 2000 cell? ...A single voltage and a single current stream (follow the connections on your battery compartment and the circuit to and from the circuit board if you don't believe me), and how you make that up matters not a bit to the camera, as long as you're above the threshold required by the camera. If the camera can work with two matched batteries of a given capacity to provide 100 shots, it should sure work if you swap one of those batteries for one with 3%, or 20%, more capacity. This is not where the answer lies to these problems.

Regarding what you can tell by looking at any numbers the smart charger is putting out -

• you can tell by touching the batteries that some of that input current is making heat, not stored capacity. That's why the totalized number can go above the rated battery capacity.
• how well matched are the independent channels in your charger? Are the channels independent? Some chargers used paired channels. If they're not applying and detecting matched voltage, current, and time parameters in independent channels, then the numbers don't compare.
• many chargers can totalize the discharge current, which seems closer to what you say you want to know. Let's say you've got two batteries whose discharge profiles cross at a certain point on the x- and y-axis (see linked graph in #36 above), chosen by the battery charger (whatever y-axis endpoint the manufacturer defined for 'fully discharged'). This is your definition of matching by capacity. The camera operates in a zone above that, voltage-wise (they usually seem to crap out around 1.1-1.2 volts, the chargers take them below 1.0 volt that I have observed.). What does the capacity number tell you about 'matching', in any sense, in the zone the camera uses? Can't those curves have un-matched profiles over any part of the range? Does that matter? (I don't think it does)
• most NiMH smart chargers just top the battery off from wherever it was when you put it in the charger. They don't discharge first, as that is not recommended for routine charging. So you're not getting a total capacity read - but maybe you're getting one that relates more closely to the number you say you want...
• if you match two batteries, are they still matched next week after 3 or 10 discharge/charge cycles? Do you have to laboriously match them each time you charge them? Are they still matched after you charge than wait a week or two before using the camera? (How do you check that the self-discharge rates are matched?) If you waited a week or two after using the camera before charging, did the self-discharge rates match, so that your next capacity matching numbers are relevant (assuming you're not discharging the batteries fully, whatever that means, as part of the re-charge process)?
• the LaCrosse charger I use, when using the capacity check routine, takes the batteries through as many charge/discharge cycles as are needed to get the same reading - whatever it's keying on to mean fully charged - twice in a row. Apparently, as often said about batteries, it can take more than one cycle, at any time in the battery's life span, to bring it fully up to capability. Is a charger with this function required to determine matching adequately?

I think this is a notorious 'measure with micrometer, cut with axe' situation. Battery performance and testing is the axe, there's no reason the camera should be designed to require micrometer precision. Most weren't in the past, I suspect most aren't these days. Batteries provide unregulated voltage and current and it's no secret they don't do this stably over any part of their cycle. Any power source varies in performance with regard to those parameters, over time, under varying load or other conditions (temperature), and between units. Electrical and electronic devices are engineered with that in mind. Alkalines - much worse than NiMH in stability of performance under load - seemed nevertheless perfectly adequate in these applications for many years.

Poor execution.

 

[Maddog59]

Well it seems that my 30 years of experience in this field is not worth much these days, so I think that I will just go on doing what I have been doing and recomending to my customers that they should not heed my advice and just use Alkaline batteries in their gear from now on. I will continue to use my matched cells and only get the 4 or 5 dives per charge that I get now knowing that if I just pick up four different batteries off the shelf they will give me a better performance than I am getting now.(BTW Do they need to be the same brand? Because from what you have been saying I can just throw any cells together and get fantastic results.)
But I digress! All I was trying to say in my original post was that if you use a good quality low discharge battery and a good charger such as the La Crosse or the Maha you will get much better performance than if you use general consumer batteries from the supermarket.


Maddog59:mooner:

Canon G10, Patima Housing, 2 x Inon Z240/4 Strobes Maha C 9000 Charger.

 

[Puffer Fish]

Well it seems that my 30 years of experience in this field is not worth much these days, so I think that I will just go on doing what I have been doing and recomending to my customers that they should not heed my advice and just use Alkaline batteries in their gear from now on. I will continue to use my matched cells and only get the 4 or 5 dives per charge that I get now knowing that if I just pick up four different batteries off the shelf they will give me a better performance than I am getting now.(BTW Do they need to be the same brand? Because from what you have been saying I can just throw any cells together and get fantastic results.)
But I digress! All I was trying to say in my original post was that if you use a good quality low discharge battery and a good charger such as the La Crosse or the Maha you will get much better performance than if you use general consumer batteries from the supermarket.


Maddog59:mooner:

Canon G10, Patima Housing, 2 x Inon Z240/4 Strobes Maha C 9000 Charger.

I happen to have both of those chargers, and over the last few years have had issues with my strobes not working correctly....(YS110's). I number the batteries when I get a set, and have traditionally bought the highest capacity I could get.

What I have found is that it is common for one of the batteries to discharge much faster than the rest...do not know about all brands, but every battery set I have purchased above 2,600 mah, after 0 to 100 cycles, has had this issue. The worst I have had was a set of Sanyo 2700's, where one fell off the table onto a hard floor. After that, the set would appear to be working, but the strobe would not flash correctly, and when tested, 90% of the load was going thru that one battery.

Up until then, I was not aware that shock can easily damage these batteries.

Since switching to the duracell low discharge, have not had the issue, but only have 80 cycles on one set... the other set of low discharge was Chinese, and made it thru 50 something cycles before having the same issue as other batteries.

I can recondition them to get the same discharge rate, and it works for one cycle... then fails again.

I suspect that both shock and bad quality control are the issue (imagine that, China having a quality control issue).

What just causes charging issues with strobes using 4, would cause a shut down in a camera using only two.

Alk. batteries, oddly enough, seem to be much more repeatable. Don't know if this is because they are easier to make, or because the process is better controlled or both.

I also will continue to use Japanese low discharge batteries now...

Note: I did not go looking for this issue, but would have my strobe suddenly not control the flash correctly....a turn off and on would work for 4 or 5 more flashes and then just strobe at maximum capacity. Have never had it happen with batteries that uniformly discharge.

Note2: I suspect this is nothing more than an internal resistance issue.

 

[spoolin01]

MadDog- it wasn't my intent to insult you or diminish your experience. I don't have detailed knowledge of battery physics or your experience with photography or cameras, but I have some basis in education and experience for understanding what's going on. Since you point to substantial performance differences between general purpose batteries as an issue, and that careful matching is critical for camera performance, I'm interested in the science and technology underlying this problem. For the moment I'm sticking with the hypothesis that for these few problem situations, it's the camera not the batteries, for the reasons already given.

Which brands have you had luck with? I've tried most of the name brands that I've seen (I don't recall anything I'd recognize as a general purpose NiMH in retail outlets - they're all name-branded) and it was the Sanyo, Sony, and Kodak specifically that I tried in my two A720s. I've also got dozens of the Tenergy generics, which continue to work reliably in my strobes - as do the name brands - which is mainly where I use NiMH batteries these days. I've seen the same thing as the post above - there is a pretty high incidence of individual batteries that are obviously different from their mates when you look at the voltage, etc while they're charging/discharging. When I buy a set I always buy a couple of extras since this is such a regular issue - it's as true of those name brands I try as of the generics. My collection of punk batteries reflects most of the brands. I'm not such a heavy user that I get anywhere near the stated 500 cycle life, probably no battery I use has gone through more than 40 or 50 cycles, this happens pretty much out of the box.

By the way, you CAN mix different brands, I've done it without issue in Ikelite strobes at least. Don't brands ever sell batteries made at different factories, or change anything in the production process - without changing the model identification so you won't unknowingly pair two branded batteries that are just as different as two batteries from different brands? Do the brands have their own factories or source their batteries from factories that don't produce the same batteries for sale under other brand names? The chemistry and capacity determine the voltage discharge profile for the most part, so far as I know. At least some of the emphasis on brand and capacity matching comes from the common use of chargers that charge all the inserted batteries as if they were in a pack, not with individual channels. I can't see how branding otherwise is critical (not that it's not a potentially good marker if you're trying to match to the n-th degree).

Again, there are two issues here. One is whether some cameras or strobes work well with some batteries and not with others. The other is whether some brands or batteries are so substandard that they aren't suitable because they fall outside the performance parameters for the NiMH technology class. I can't see that the simple information available from observing the smart chargers or from A-B testing that I can do indicates that the second proposition is a practical problem for most devices, or that having to find a new battery technology or laboriously seek out and preserve tightly matched battery sets for each device is the expected solution because of an intractable mismatch between engineering capability and NiMH battery specs. The vast majority of devices prove that, I'd say.

This discussion would benefit from someone who knows something on the camera or strobe circuitry side as to why it matters for some devices but not others.

 

[bvanant]

This continues to grow. My auction a570 should arrive soon. My guess is that the Canon guys made a really poor decision with either the components or the design of the low battery alarm circuit. Given that the circuit is probably difficult to figure out from just having the board, we will try to figure out how to make it work or not with both some controlled voltage and noisy inputs. As for paired batteries, I don't think it makes much difference in strobes at all, I routinely mix both traditional NiMH and low discharge in the same strobe with no apparent issues. Same for focus lights. As for the camera, I am not so sure since it probably was designed around 5V or 3V components and one bad battery might cause some issues.

In any case the fun continues.

Bill

 

[Maddog59]

I happen to have both of those chargers, and over the last few years have had issues with my strobes not working correctly....(YS110's). I number the batteries when I get a set, and have traditionally bought the highest capacity I could get.

What I have found is that it is common for one of the batteries to discharge much faster than the rest...do not know about all brands, but every battery set I have purchased above 2,600 mah, after 0 to 100 cycles, has had this issue. The worst I have had was a set of Sanyo 2700's, where one fell off the table onto a hard floor. After that, the set would appear to be working, but the strobe would not flash correctly, and when tested, 90% of the load was going thru that one battery.

Up until then, I was not aware that shock can easily damage these batteries.

Since switching to the duracell low discharge, have not had the issue, but only have 80 cycles on one set... the other set of low discharge was Chinese, and made it thru 50 something cycles before having the same issue as other batteries.

I can recondition them to get the same discharge rate, and it works for one cycle... then fails again.

I suspect that both shock and bad quality control are the issue (imagine that, China having a quality control issue).

What just causes charging issues with strobes using 4, would cause a shut down in a camera using only two.

Alk. batteries, oddly enough, seem to be much more repeatable. Don't know if this is because they are easier to make, or because the process is better controlled or both.

I also will continue to use Japanese low discharge batteries now...

Note: I did not go looking for this issue, but would have my strobe suddenly not control the flash correctly....a turn off and on would work for 4 or 5 more flashes and then just strobe at maximum capacity. Have never had it happen with batteries that uniformly discharge.

Note2: I suspect this is nothing more than an internal resistance issue.

Puffer Fish, you are right on the money when you say it's an internal resistance problem. but as most cameras have a very narrow band width for voltage. if you have one cell that is dragging the others down and it causes the voltage to drop below the camera shut down voltage(usually about 1.0volt), your going to have troubles and as flash units don't have a shutdown voltage they just stop charging and you have the same trouble for the same reason.
Over the years I have made many hundreds of battery packs, mainly in the past with Nicd cells up to 10000mHa and 36 volts for both Military and Emergency service apllications as well as consumer based products but these days it is mainly Nmhi cells that I use and I am still learning about the pros and cons of each type of Nmhi brand. I have talked with many "experts" in this field and have found that you can get twenty different opinions from twenty different people on most topics when it comes to the properties of batteries and the reasons why they behave a particular way. One of the main reasons I troll this forum is to see what problems people are having with batteries in their equipment. This problem of flash units and cameras behaving eraticaly seems to be a very common problem. I even have my Mother In-Law complaining at the moment that her camera is eating batteries.
So I'm not sure what the answer is to this question but I don't think it's a camera problem per se but more of an incompatability issue with high discharge batteries. Like you, I only use Japanese low discharge cells in my flash unit and I seem to be getting very good and consistant numbers from them. I also number the cells to keep track of them.
And as I first stated in this thread, the chargers I use aren't the total answer but they help me to keep track of where my cells are at.


Maddog59

Canon G10, Patima Housing, 2 x Z240/4 Strobes hard wired(because I'm old fashioned) eneloop batteries and Maha C 9000 charger.

 

[Maddog59]

MadDog- it wasn't my intent to insult you or diminish your experience. I don't have detailed knowledge of battery physics or your experience with photography or cameras, but I have some basis in education and experience for understanding what's going on. Since you point to substantial performance differences between general purpose batteries as an issue, and that careful matching is critical for camera performance, I'm interested in the science and technology underlying this problem. For the moment I'm sticking with the hypothesis that for these few problem situations, it's the camera not the batteries, for the reasons already given.

Which brands have you had luck with? I've tried most of the name brands that I've seen (I don't recall anything I'd recognize as a general purpose NiMH in retail outlets - they're all name-branded) and it was the Sanyo, Sony, and Kodak specifically that I tried in my two A720s. I've also got dozens of the Tenergy generics, which continue to work reliably in my strobes - as do the name brands - which is mainly where I use NiMH batteries these days. I've seen the same thing as the post above - there is a pretty high incidence of individual batteries that are obviously different from their mates when you look at the voltage, etc while they're charging/discharging. When I buy a set I always buy a couple of extras since this is such a regular issue - it's as true of those name brands I try as of the generics. My collection of punk batteries reflects most of the brands. I'm not such a heavy user that I get anywhere near the stated 500 cycle life, probably no battery I use has gone through more than 40 or 50 cycles, this happens pretty much out of the box.

By the way, you CAN mix different brands, I've done it without issue in Ikelite strobes at least. Don't brands ever sell batteries made at different factories, or change anything in the production process - without changing the model identification so you won't unknowingly pair two branded batteries that are just as different as two batteries from different brands? Do the brands have their own factories or source their batteries from factories that don't produce the same batteries for sale under other brand names? The chemistry and capacity determine the voltage discharge profile for the most part, so far as I know. At least some of the emphasis on brand and capacity matching comes from the common use of chargers that charge all the inserted batteries as if they were in a pack, not with individual channels. I can't see how branding otherwise is critical (not that it's not a potentially good marker if you're trying to match to the n-th degree).

Again, there are two issues here. One is whether some cameras or strobes work well with some batteries and not with others. The other is whether some brands or batteries are so substandard that they aren't suitable because they fall outside the performance parameters for the NiMH technology class. I can't see that the simple information available from observing the smart chargers or from A-B testing that I can do indicates that the second proposition is a practical problem for most devices, or that having to find a new battery technology or laboriously seek out and preserve tightly matched battery sets for each device is the expected solution because of an intractable mismatch between engineering capability and NiMH battery specs. The vast majority of devices prove that, I'd say.

This discussion would benefit from someone who knows something on the camera or strobe circuitry side as to why it matters for some devices but not others.

Hi Spoolin01,
No offence taken and none meant, this is a forum for people to air their opinions and to gain knowledge from other like minded enthusiasts. I also appreciate where you are coming from when you say that you are interested in the science of the subject. I myself,am more interested in the application of the technology and the associated problems there in.
Your first point as to name brands is valid in that most cells are named by the manufacturer but what I was trying to get at is that if you walk in to a supermarket and buy a set of Sanyo Nimh AA cells (standard Sanyo 2500 mAh cells) you won't get the same battery as if you were to buy your batteries from a specialist dealer who if asked, will recomend the right cell for your particular application. (say Sanyo eneloop 2000 mAh low discharge cells) There is a big difference in the performance of just these two brand name cells! I'm sure if you tried a set of the eneloop cells in your A720's you find a much better performance over the other brands you named.
Secondly, yes you can mix and match cells of different brands and capacity but you won't get anywhere near the same performance from the pack.
Third, the performance of particular Nmhi cells is governed by the makeup of the technology used in the cell manufacture and as different aplplications need different power requirements the manufacturers make the cells to suit. It is up to the consumer to decide which technology is best for their application. This is why you can buy different type of disposable cells from carbon technology to hi performance alkalines and Nmhi disposables.
Also the charger I use has individual channels for each cell and monitors the cells accordingly.

These links were on a post in the underwater photograhpy section and I thought they might be relevent to this discussion:

Review: Pre-Charged (Low Self-Discharge) Rechargeable Battery Comparison

Review: Testing Sanyo's Eneloop Low Self-Discharge Rechargeable Battery



Maddog59:mooner:


Canon G10, Patima Housing, 2 x Z240/4 strobes hard wired, (because I'm old fashioned) eneloop batteries and a Maha MH-C 9000 charger - Analyzer.:mooner:

 

[spoolin01]

Comparing Eneloop and standard NiMH technology is a red herring. Forget what brand or technology is providing the power, consider it as a black box. To explain the problems cited as battery technology and not camera design, you've got to show that somehow, standard NiMH battery technology is inadequate to provide a basically stable, repeatable, and known voltage over the expected total current discharge. Even garden variety NiMHs do it well, so far as I can tell. If it will power a strobe or light, it will power a camera. The job of final voltage regulation is in the camera (or strobe or - often but not always - in the light), not in the battery. Thank god Canon didn't design the engine computer in my Ford...

My issue with this discussion is with the continued assertion that there are these special batteries, either good (that perhaps only specialty retailers can get) or bad, within the typical NiMH offerings. Can anyone provide any testing data (not camera testing...) to back this up? Again, I'm not talking about Eneloops, but feel free to show data about any other long-standing NiMH brand you know of. It would be particularly convincing to see data from battery pairs where either the rated capacities are different by some middling amount, or where one matched-rating battery is older and has lost a middling amount of capacity through normal aging, or from brands which behave differently. I'd like to see the enormous voltage spike when you put the pair together that would explain how the poor Canon engineers missed building in the compliance to handle it, this completely unusable power source. Remember - these aren't dead or defective batteries, just not exquisitely matched (or special), and if you do any of the garage-mechanic testing on them - capacity verification, voltage, charge/discharge rate, you don't see any qualitative differences in the performance of these batteries (total capacity could differ, but that doesn't explain why they fail in the cameras right out of the charger). That's the little data I've seen or generated, I'd love to see the rest. Until data is brought forth, I still stand by my suspicion: the electrons are there, and at a usable voltage. The engineers just didn't design properly around the well-established specs of the power source.