K-x owners: NiMH batteries results please

Eruditass · 11-11-2009, 07:32 PM

Just wanted to say that my K-x actually works better with many of my NiMH on Auto, versus NiMH mode.

tomtor · 11-11-2009, 11:09 PM

Originally posted by noou

what's your point? also the guy that had reached 1000+ shots with eneloops must have reviewed his photos on the lcd and so on...

no design to argue further: here we are discussing a real problem, all the rest is useless

My point is that you are spreading misinformation. You state that the Pentax number of 640 exposures is a pessimistic guess, but it is the other way around. The CIPA standard is an optimistic estimate, not the normal behavior of most users.

When you get 350 exposures in normal usage with some LV, video and viewing your images than that is a match with the 640 exposure CIPA specification. You may state otherwise but that's based on nothing, so there is indeed no reason for me to discuss this with you any further.

tomtor · 11-12-2009, 12:23 AM

Originally posted by OutOfFocus

I will buy a suitable resistor on my way home today and measure the discharge current and voltage under better known conditions.

That will be interesting. You'll need a 1 ohm with 2 watt thermal dissipation capacity to mimic a K-X with LV. You'll probably need a bunch of standard resistors in parallel or you'll create some smoke :-)

The whole issue with the K-X is not really a firmware flaw, but that the engineers decided that you'll only get green/orange with batteries that are capable of sustaining the load of LV and video.

An alternative would have been to introduce a yellow battery mode in which LV/video is disabled. Than you would have K-M like behavior and people could use lesser NiMHs if they don't value LV or video.

Should perhaps be added to the firmware wish list. I'll do that...

jup · 11-12-2009, 01:34 AM

Originally posted by Eruditass

Just wanted to say that my K-x actually works better with many of my NiMH on Auto, versus NiMH mode.

I had similar experience. Also worked with my NiMH better on alkaline setting then NiMH setting. Seems that it's actually more tolerant to alkaline then NiMH batteries, and sometimes on auto it decides that those inserted NiMHs are actually alkalines.

OutOfFocus · 11-12-2009, 06:21 AM

Continuing the saga of my Duracell 2650's:

The discharge capacities of the cells were all approximately 2400 mAh. I recharged them at 1500 mA and put them in the camera as soon as they were charged.

The camera turned on immediately with a green battery indicator. I played for a while, took a dozen or so shots, used LV a bit. I turned the camera off and on, played some more, took a few more shots. Waited overnight, turned camera on, used LV, took a few more shots. All this time, the battery indicator remained green.

I turned the camera off, opened the battery compartment, waited a short while, closed it, waited a short while (about 10 seconds), turned power switch on. Nothing. Turned camera off and on again, and this time it turns on with a red battery indicator. Tried LV. Battery indicator still red. Turned camera off and on, tried LV again, etc. Still red. Opened battery compartment, repeat all the above. First power: nothing. Second and subsequent power ons: red indicator the entire time.

I took the batteries out and discharged them one at a time into three 10 ohm resistors connected in parallel (i.e. a 3.333 ohm resistor). Each battery read 1.28 V while discharging. I calculate the current to be about 380 mA.

OutOfFocus · 11-12-2009, 06:28 AM

Discharging into a single 1 ohm 10 watt resistor: voltages were 1.16, 1.18, 1.18, and 1.19 V.

OutOfFocus · 11-12-2009, 06:55 AM

Originally posted by tomtor

The whole issue with the K-X is not really a firmware flaw, but that the engineers decided that you'll only get green/orange with batteries that are capable of sustaining the load of LV and video.

An alternative would have been to introduce a yellow battery mode in which LV/video is disabled. Than you would have K-M like behavior and people could use lesser NiMHs if they don't value LV or video.

Should perhaps be added to the firmware wish list. I'll do that...

Perhaps you could split the current indicator into two halves: left side is battery capacity for photo mode, right side for LV/Video mode, with solid red for low and black for disabled. (Black/black is battery discharged and camera turns off.)

tomtor · 11-12-2009, 07:00 AM

Originally posted by OutOfFocus

Discharging into a single 1 ohm 10 watt resistor: voltages were 1.16, 1.18, 1.18, and 1.19 V.

That's interesting, that means that those voltages are sufficient for getting the green status in the K-X, because you used these with success in your K-X

I wonder what the results are with batteries which never give green or yellow status after being inserted in a K-X, I assume much lower voltages.

tomtor · 11-12-2009, 07:01 AM

Originally posted by OutOfFocus

Perhaps you could split the current indicator into two halves: left side is battery capacity for photo mode, right side for LV/Video mode, with solid red for low and black for disabled. (Black/black is battery discharged and camera turns off.)

Good idea, pure luxury :-)

tomtor · 11-12-2009, 07:06 AM

Originally posted by OutOfFocus

Continuing the saga of my Duracell 2650's:

I turned the camera off, opened the battery compartment, waited a short while, closed it, waited a short while (about 10 seconds), turned power switch on. Nothing. Turned camera off and on again, and this time it turns on with a red battery indicator. Tried LV. Battery indicator still red. Turned camera off and on, tried LV again, etc. Still red. Opened battery compartment, repeat all the above. First power: nothing. Second and subsequent power ons: red indicator the entire time.

The behavior after opening the battery department is IMO really a firmware flaw. It should give a similar battery reading as before removing them. I cannot see any reason for that, when you specify the use of NiMH. In auto mode I can imagine it guesses wrong.

Thanks for your experiments.

Eruditass · 11-12-2009, 10:53 AM

Here is some thorough controlled testing, please verify if you get a chance!

Re: K-x Battery Experience (Part 2): Pentax SLR Talk Forum: Digital Photography Review

lattyday · 11-12-2009, 06:30 PM

So what's the consensus, here? Which rechargeables have seemed to work the best so far? I want to make sure I get some before my k-x arrives next week...

Eruditass · 11-12-2009, 06:34 PM

I'd go with eneloop or duracell pre-charged white top (if they are still around).

Pentax in Europe has been shipping with eneloops and Ned Bunnell says he uses them, so I'd go with that

**Aristophanes** · 11-12-2009, 08:08 PM

Originally posted by lattyday

So what's the consensus, here? Which rechargeables have seemed to work the best so far? I want to make sure I get some before my k-x arrives next week...

Eneloops or any recent Powerex/Maha/Imedion.

Rechargeable Batteries Battery Chargers Rechargeable Lithium Digital Camera Batteries Maha Ansmann Energizer Sanyo ZTS

tomtor · 11-13-2009, 12:28 AM

Eneloops is without doubt the safest choice, but indeed the white top Duracell pre-charged work as well. I and others also had great results with Varta 2500 mAh.

11-12-2009, 12:23 AM	#93
tomtor Veteran Member Join Date: Apr 2008 Location: Netherlands Posts: 382	Yellow Reduced Mode Originally posted by OutOfFocus I will buy a suitable resistor on my way home today and measure the discharge current and voltage under better known conditions. That will be interesting. You'll need a 1 ohm with 2 watt thermal dissipation capacity to mimic a K-X with LV. You'll probably need a bunch of standard resistors in parallel or you'll create some smoke :-) The whole issue with the K-X is not really a firmware flaw, but that the engineers decided that you'll only get green/orange with batteries that are capable of sustaining the load of LV and video. An alternative would have been to introduce a yellow battery mode in which LV/video is disabled. Than you would have K-M like behavior and people could use lesser NiMHs if they don't value LV or video. Should perhaps be added to the firmware wish list. I'll do that...

11-12-2009, 06:21 AM	#95
OutOfFocus Senior Member Join Date: Aug 2009 Location: Houston, TX Photos: Gallery Posts: 140	Update Continuing the saga of my Duracell 2650's: The discharge capacities of the cells were all approximately 2400 mAh. I recharged them at 1500 mA and put them in the camera as soon as they were charged. The camera turned on immediately with a green battery indicator. I played for a while, took a dozen or so shots, used LV a bit. I turned the camera off and on, played some more, took a few more shots. Waited overnight, turned camera on, used LV, took a few more shots. All this time, the battery indicator remained green. I turned the camera off, opened the battery compartment, waited a short while, closed it, waited a short while (about 10 seconds), turned power switch on. Nothing. Turned camera off and on again, and this time it turns on with a red battery indicator. Tried LV. Battery indicator still red. Turned camera off and on, tried LV again, etc. Still red. Opened battery compartment, repeat all the above. First power: nothing. Second and subsequent power ons: red indicator the entire time. I took the batteries out and discharged them one at a time into three 10 ohm resistors connected in parallel (i.e. a 3.333 ohm resistor). Each battery read 1.28 V while discharging. I calculate the current to be about 380 mA.

11-12-2009, 06:28 AM	#96
OutOfFocus Senior Member Join Date: Aug 2009 Location: Houston, TX Photos: Gallery Posts: 140	Further update Discharging into a single 1 ohm 10 watt resistor: voltages were 1.16, 1.18, 1.18, and 1.19 V.

11-12-2009, 06:55 AM	#97
OutOfFocus Senior Member Join Date: Aug 2009 Location: Houston, TX Photos: Gallery Posts: 140	Sounds like a good idea Originally posted by tomtor The whole issue with the K-X is not really a firmware flaw, but that the engineers decided that you'll only get green/orange with batteries that are capable of sustaining the load of LV and video. An alternative would have been to introduce a yellow battery mode in which LV/video is disabled. Than you would have K-M like behavior and people could use lesser NiMHs if they don't value LV or video. Should perhaps be added to the firmware wish list. I'll do that... Perhaps you could split the current indicator into two halves: left side is battery capacity for photo mode, right side for LV/Video mode, with solid red for low and black for disabled. (Black/black is battery discharged and camera turns off.)

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11-11-2009, 07:32 PM	#91
Eruditass Veteran Member Join Date: Jul 2009 Photos: Gallery Posts: 2,207 Original Poster	Just wanted to say that my K-x actually works better with many of my NiMH on Auto, versus NiMH mode.

11-11-2009, 11:09 PM	#92
tomtor Veteran Member Join Date: Apr 2008 Location: Netherlands Posts: 382	Originally posted by noou what's your point? also the guy that had reached 1000+ shots with eneloops must have reviewed his photos on the lcd and so on... no design to argue further: here we are discussing a real problem, all the rest is useless My point is that you are spreading misinformation. You state that the Pentax number of 640 exposures is a pessimistic guess, but it is the other way around. The CIPA standard is an optimistic estimate, not the normal behavior of most users. When you get 350 exposures in normal usage with some LV, video and viewing your images than that is a match with the 640 exposure CIPA specification. You may state otherwise but that's based on nothing, so there is indeed no reason for me to discuss this with you any further.

11-12-2009, 01:34 AM	#94
jup Senior Member Join Date: Nov 2009 Location: San Jose, CA Posts: 103	Originally posted by Eruditass Just wanted to say that my K-x actually works better with many of my NiMH on Auto, versus NiMH mode. I had similar experience. Also worked with my NiMH better on alkaline setting then NiMH setting. Seems that it's actually more tolerant to alkaline then NiMH batteries, and sometimes on auto it decides that those inserted NiMHs are actually alkalines.

11-12-2009, 07:00 AM	#98
tomtor Veteran Member Join Date: Apr 2008 Location: Netherlands Posts: 382	Originally posted by OutOfFocus Discharging into a single 1 ohm 10 watt resistor: voltages were 1.16, 1.18, 1.18, and 1.19 V. That's interesting, that means that those voltages are sufficient for getting the green status in the K-X, because you used these with success in your K-X I wonder what the results are with batteries which never give green or yellow status after being inserted in a K-X, I assume much lower voltages.

11-12-2009, 07:01 AM	#99
tomtor Veteran Member Join Date: Apr 2008 Location: Netherlands Posts: 382	Originally posted by OutOfFocus Perhaps you could split the current indicator into two halves: left side is battery capacity for photo mode, right side for LV/Video mode, with solid red for low and black for disabled. (Black/black is battery discharged and camera turns off.) Good idea, pure luxury :-)

11-12-2009, 07:06 AM	#100
tomtor Veteran Member Join Date: Apr 2008 Location: Netherlands Posts: 382	Originally posted by OutOfFocus Continuing the saga of my Duracell 2650's: I turned the camera off, opened the battery compartment, waited a short while, closed it, waited a short while (about 10 seconds), turned power switch on. Nothing. Turned camera off and on again, and this time it turns on with a red battery indicator. Tried LV. Battery indicator still red. Turned camera off and on, tried LV again, etc. Still red. Opened battery compartment, repeat all the above. First power: nothing. Second and subsequent power ons: red indicator the entire time. The behavior after opening the battery department is IMO really a firmware flaw. It should give a similar battery reading as before removing them. I cannot see any reason for that, when you specify the use of NiMH. In auto mode I can imagine it guesses wrong. Thanks for your experiments.

11-12-2009, 10:53 AM	#101
Eruditass Veteran Member Join Date: Jul 2009 Photos: Gallery Posts: 2,207 Original Poster	Here is some thorough controlled testing, please verify if you get a chance! Re: K-x Battery Experience (Part 2): Pentax SLR Talk Forum: Digital Photography Review

11-12-2009, 06:30 PM	#102
lattyday Forum Member Join Date: Nov 2009 Location: Mankato, MN Posts: 56	So what's the consensus, here? Which rechargeables have seemed to work the best so far? I want to make sure I get some before my k-x arrives next week...

11-12-2009, 06:34 PM	#103
Eruditass Veteran Member Join Date: Jul 2009 Photos: Gallery Posts: 2,207 Original Poster	I'd go with eneloop or duracell pre-charged white top (if they are still around). Pentax in Europe has been shipping with eneloops and Ned Bunnell says he uses them, so I'd go with that

11-12-2009, 08:08 PM	#104
Aristophanes Site Supporter Join Date: Jul 2008 Location: Rankin Inlet, Nunavut Photos: Albums Posts: 3,948	Originally posted by lattyday So what's the consensus, here? Which rechargeables have seemed to work the best so far? I want to make sure I get some before my k-x arrives next week... Eneloops or any recent Powerex/Maha/Imedion. Rechargeable Batteries Battery Chargers Rechargeable Lithium Digital Camera Batteries Maha Ansmann Energizer Sanyo ZTS

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11-13-2009, 12:28 AM	#105
tomtor Veteran Member Join Date: Apr 2008 Location: Netherlands Posts: 382	Eneloops is without doubt the safest choice, but indeed the white top Duracell pre-charged work as well. I and others also had great results with Varta 2500 mAh.