[clarenceclose]

I had purchased (2) Minolta NP-400 batteries (Li-Ion, 7.4V, 1500 mAh) as spares for my K10D and had no problem with them until I tried continuous shooting.
fn button/up arrow/continuous shooting/OK/OK
then select subject and go for continuous shoot by holding down the shutter release.
2-3 shots max then get 'battery depleted' on LCD. Top LCD show graphic of depleted battery.
Turn camera off and back on and the top LCD shows graphic of full battery.
Do continuous shoot again, same problem, same fix.
Same problem with both batteries and they are definitely fully charged.

Put in Pentax battery that came with the camera (Li-Ion, 7.4V, 1650 mAh) do the above and can shoot until the card is full.

The Minolta spares work fine for one shutter release/one shot.

Anyone else have similar experience?
Defective batteries or just not hot enough to do the work?

[Tom Brown]

It could be they are protected cells and are cutting out on their protection circuit. This would happen if they are not designed to drive the current required by the 10D.

Have you tried it with SR switched off? If you lower the current demands, the Minolta batteries might work fine.

[NaClH2O]

Hi Clarence, just a guess here, but where I work we do a LOT of work with sensitive electronics at small voltages/amperage, and while it doesn't seem like a lot 150mAh difference could be enough to shut down the camera during continuous shooting. I do know that that amount of difference can shut down our propulsion logic and turn off power to a 600V subway motor. Maybe you will have to reserve the Pentax battery for that and rely on the Minolta's for individual shooting.

NaCl(just my own $.05 and worth all of that)H2O

[clarenceclose]

Thanks. Will check with the SR off too. Good tip.
Another thing I noticed but failed to mention: The Minolta batteries do the same fail if I take to many photos to fast, which is similar to continuous shooting mode.
Appreciate the inputs.

Checked it out with SR off and it works in continuous mode fine. Must be too much draw does the shut down.
Thanks again.

[Alvin]

Hi Clarence, just a guess here, but where I work we do a LOT of work with sensitive electronics at small voltages/amperage, and while it doesn't seem like a lot 150mAh difference could be enough to shut down the camera during continuous shooting. I do know that that amount of difference can shut down our propulsion logic and turn off power to a 600V subway motor. Maybe you will have to reserve the Pentax battery for that and rely on the Minolta's for individual shooting.

NaCl(just my own $.05 and worth all of that)H2O

Clarence,

Salty's been giving a lot of nickles lately Here's two more.

I've been having a problem with my cellphone when I used a "new" battery. Similar spec, fits my phone just fine, and it came from the same manufacturer, it was just designed for a different series phone. Use the cellphone normally, no problem, switch to speaker phone, everything goes haywire.

So I'm coming to the same conclusion as Salty and Tom, they just beat me to the punch.

[newtmaker]

I just checked my K10D with the B&H Battery. Works just like the Pentax version.
Are the Minolta batteries smaller ah rating?

Walt

[rprii]

mAh (milliAmpHours) is a rating of the approximate amount of time a battery will last between charges. The important figure is the voltage . . . as long as the voltage is 7.4, you should not have a problem. I have a Lenmar equivalent that is rated at 1500mAh . . . I cannot tell the difference between it and the oem Pentax (rated at 1620 mAh). I can rip off continuous shots until the card is full with either battery.
Sounds to me like you got a couple of defective batteries.

[Tom Brown]

Are the Minolta batteries smaller ah rating?

The problem isn't the Ah rating.

If you were to short a Li-Ion out, or allow it to reverse current (most likely because it's in series with a stronger cell), Li-Ions will fail in a manner battery manufacturers describe as, "rapid vent with flame".

This is what happened to the famous Dell and Sony laptops.

For this reason, most Li-Ion cells have a protection circuit that will disconnect the battery in the event of being discharged too quickly (short protection) or being completely drained (low charge protection). If a device draws energy too quickly, the protection circuitry on the cell will think the cell is shorted and it is designed to disconnect in this event.

The circuit is doing it's job. The problem is the circuit and possibly the energy cell wasn't designed for the load a K10D demands.

It's hard to believe there are electronics inside a tiny battery but they're usually in there and with the highly publicised laptop meltdowns, I'd be surprised if we see any unprotected cells at all anymore.

[rprii]

The problem isn't the Ah rating.

If you were to short a Li-Ion out, or allow it to reverse current (most likely because it's in series with a stronger cell), Li-Ions will fail in a manner battery manufacturers describe as, "rapid vent with flame".

This is what happened to the famous Dell and Sony laptops.

For this reason, most Li-Ion cells have a protection circuit that will disconnect the battery in the event of being discharged too quickly (short protection) or being completely drained (low charge protection). If a device draws energy too quickly, the protection circuitry on the cell will think the cell is shorted and it is designed to disconnect in this event.

The circuit is doing it's job. The problem is the circuit and possibly the energy cell wasn't designed for the load a K10D demands.

It's hard to believe there are electronics inside a tiny battery but they're usually in there and with the highly publicised laptop meltdowns, I'd be surprised if we see any unprotected cells at all anymore.

Relating apples to oranges . . . see my previous post or do some study on the internet as to the meaning of mAh & voltage. whether it is LIon, AA Lithium, etc, . . . bottomline is voltage not mAh. Again, mAh petains to longevity not output power.

Totally different issue as relates to Dell/Sony . . . btw . . . between myself and my employees, we have about 30 Dells anbd 60 IBMs . . . none had a problem . . . the sky is falling !!!!!

Investigate and judge for yourself . . . it is easy.

[Tom Brown]

. . . see my previous post or do some study on the internet as to the meaning of mAh & voltage.

I fancy myself reasonably well versed in the areas of mAh, voltage, and battery technology.

. . . bottomline is voltage not mAh.

If you will read the first line of my response, I think you will see that you are flaming the wrong person.

Again, mAh petains to longevity not output power.

mAh pertains to a cell's ability to source current over time. Power capacity would be rated in Wh or a prefixed derivative.

Totally different issue as relates to Dell/Sony . . .

No. It was the same issue. The problem was not with the Li-Ion chemistry but rather the failure of the protection circuitry to prevent current flowing through the cells from reversing. In this case, the circuit is not failing but it is preventing the battery to function at high current loads. Citing the laptop issues was simply a way to demonstrate the requirement Li Ion cells have for protective circuitry because they have an extremely high energy density and can be dangerous if mistreated.

The protection circuit issue with the Sony batteries is well documented.

btw . . . between myself and my employees, we have about 30 Dells anbd 60 IBMs . . .

The company I work for has several thousand laptops, mostly IBM but a few hundred Dells as well. We've had no explosive battery failures either. Do I win something? lol!

it is easy.

rprii, I believe if you will carefully read my post you will find that I bear a strong understanding of the principals and technology involved here. This is how I was able to take an educated guess as to the cause of clarence's problem. The protection circuit is the only logical thing that could cause the cited issue.

If you wish to compare education and experience in the areas of electrical theory or battery technology, that is fine with me. Regardless of who may be superior in some way, however, is there not a way we can conduct ourselves as gentlemen?

I believe you have not read my post carefully and have chosen to flame with little understanding of the concept I was trying to convey.

[-=JoN=-]

got an impact battery from b and h as a secondary, it's performance has been spotty. figure might as well just plunk down the extra dough for a good set....

[clarenceclose]

Thank you all. This has been very informative and educational.

As I had said, after the initial information, when I run with SR off the battery performs in continuous mode with no trouble so I would agree with Tom that there is some protective mechanism in the Minolta battery that prevents it from such a discharge under the higher draw required with the SR.

Another good thing I learned is the SR must have a pretty good drain on the battery which would shorten the amount of long term power in the form of photo count before expiration of the charge. This could have serious ramifications should I choose to go on a backpack and only have the batteries as a power source. From now on I will run with the SR off unless needed for lower light situations.

Again, thanks to you all.

[trog100]

another reason for the off switch.. SR consumes a fair about of power.. having used a panasonic FZ20 that has no shake reduction off switch and dosnt seem to suffer by it i have wondered why pentax felt the need to "imply" it has problems by the inclusion of an off switch..

useing the system as a dust cleaner wont help either.. especially if its set to activate every time the camera is turned on..

i do wonder about its longevity as well..

trog

[rprii]

another reason for the off switch.. SR consumes a fair about of power.. having used a panasonic FZ20 that has no shake reduction off switch and dosnt seem to suffer by it i have wondered why pentax felt the need to "imply" it has problems by the inclusion of an off switch..

useing the system as a dust cleaner wont help either.. especially if its set to activate every time the camera is turned on..

i do wonder about its longevity as well..

trog

Unless Pentax is lying, SR adds little, if any, power demands . . .
From the Pentax SR Guide . . .
"Since the SR system is activated only when you press the shutter release, any effect on battery consumption is negligible."
and
"Does battery life change while the SR system is engaged?
No, battery life remains the same whether the SR system is turned on or off."

you can go here to access the entire document . . .
http://www.pentaxslr.com/files/scms_docs//PENTAX_SR_Description_091506.pdf

Have not seen any white papers about the DR system but it probably does reduce battery life expectancy . . . but does not add excessive draw . . . I seriously doubt that Pentax would add a feature that is going to have a power requirement higher than the batteries rated voltage. My guess is that it is also "negligible". Unless, maybe, you turn your camera on/off several hundred times a day.

Based on my own experience and the threads I have seen, the expentancy of these batteries, whether OEM or third-party, is pretty amazing. Generally, I get over 800 shots per charge and that includes direct USB transfer to my desktopl/laptop.

BTW, except when using a tripod, I have SR "on" all the time. I only use DR ocassionally.

[Alvin]

"Since the SR system is activated only when you press the shutter release, any effect on battery consumption is negligible."

In burst mode, you have your finger already holding down the shutter for 3 or 4 frames in a row (perhaps more), I would assume this would keep the SR activated between the frames, adding more electrical load. Even if it is what we, or Pentax, consider negligible, Clarence is using a non-Pentax battery and the added electrical load may have been enough to trigger the camera (or the battery) to cut the circuit.