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09-30-2011, 04:02 PM   #16
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QuoteOriginally posted by theodoros1978 Quote
Maybe i should have bought the normal eneloops
Don't worry about it. Just keep the batteries in the camera until they run flat, and see how long they last. That's the only way to really test the battery.

The K-x battery metering does does have some 'personality'. It sometimes takes it a while to figure out whether it likes new batteries.

Furthermore, as the XX eneloops are pretty new, Pentax would have had no chance to calibrate the K-x battery metering against them (for their current, drain rate etc) when they designed the camera battery circuit or the firmware. (Assuming that they would do such calibration anyhow).

09-30-2011, 04:26 PM   #17
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QuoteOriginally posted by theodoros1978 Quote
however, it is strange that battey was green and then turned orange in few shots. The package says that batteries are precharged. Maybe i should have bought the normal eneloops
Boy you worry too much. Just set the camera to NiMH and fully recharge the XX b4 using.
09-30-2011, 11:50 PM   #18
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QuoteOriginally posted by UnknownVT Quote
edit...
A lot of people report getting over 500 shots/charge on regular eneloops -
some over 1,000 (my average is about 1,200) -
of course depends on usage - if that's not enough -
then perhaps one could consider these eneloop XX.

In theory the eneloop XX ought to have 2500/2000 % = 125% the capacity of the regular eneloop -
see: Batteries - SANYO eneloop | Ready to use Rechargeable Battery
that is 25% more capacity - a significant amount -

that's getting about 625 shots per charge instead of 500;
or 1,250 instead of 1,000 at the upper end

- but is that worth over double the price?

The other very important point - as capacity is NOT everything....

edit...

However I would very interested in anyone who has used the eneloop XX
to compare with the regular eneloops in Pentax (AA) dSLRs.
The math for your 625 shot number can tossed out. Batteries don't discharge to zero so the simple ratio doesn't work in this case. But I am very interested in comparisons between XX and regular. I don't have any extended trips coming up until next summer but I would definitely get a set or two if there was a substantial difference.

In addition to being able to recharge the XX fewer times, the XX batteries also discharge faster. XX will be at 75% after 1 compared to 3 yrs for regular eneloop. But both of these are not important to me.
10-01-2011, 12:11 AM   #19
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QuoteOriginally posted by RickyFromVegas Quote
La Crosse battery chargers.
They go for about $50 or so, but it's nice. Not a necessity, but a luxury.
I've been using a La Crosse BC-900 for years. It's a great charger.

10-01-2011, 04:12 AM   #20
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QuoteOriginally posted by abacus07 Quote
The math for your 625 shot number can tossed out. Batteries don't discharge to zero so the simple ratio doesn't work in this case.
The standard IEC (International Electrotechnical Commission) capacity measurements do NOT discharge the battery down to zero:

The IEC standard test is to discharge the cell at 0.2C down to 1.0 V at a temperature of 25 Celsius following a standard charge.

extract from: [pdf] Test Methodology For Determining Energy Efficiency of Battery ...
http://www.energystar.gov/ia/partners/prod_development/downloads/Battery_Cha...est_Method.pdf
(US government Energy Star program)



Everything else being equal, then it is entirely reasonable to expect a battery with 25% more capacity to last 25% longer, therefore deliver 25% more shots.

However everything is often not equal - hence variance from a simple linear relationship -
but one ought to expect more shots from a battery (of the same type) with more capacity -
provided the capacity rating is accurate -
since these are both eneloops from Sanyo (who are very reputable)
it is reasonable to expect more shots from the eneloop XX over the regular eneloop.

Last edited by UnknownVT; 10-01-2011 at 04:41 AM.
10-01-2011, 04:58 AM   #21
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QuoteOriginally posted by UnknownVT Quote
Everything else being equal, then it is entirely reasonable to expect a battery with 25% more capacity to last 25% longer, therefore deliver 25% more shots.

However everything is often not equal - hence variance from a simple linear relationship -
but one ought to expect more shots from a battery (of the same type) with more capacity -
provided the capacity rating is accurate -
since these are both eneloops from Sanyo (who are very reputable)
it is reasonable to expect more shots from the eneloop XX over the regular eneloop.
No, it doesn't. capacity ratio is worthless. The only it tells us is that we should expect more shots with XX eneloops. A second variable to consider is that the XX batteries probably discharge (a little) faster than regular eneloops while taking photos. We know that the XX batteries discharge faster while sitting in a box (75% at 1 yr vs 3 yrs). but in the end the math tells me nothing. I want to hear some comparisons between the two battery types from K-x/K200D users with consistent usage patterns.
10-01-2011, 05:15 AM   #22
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QuoteOriginally posted by abacus07 Quote
The math for your 625 shot number can tossed out.
QuoteOriginally posted by abacus07 Quote
No, it doesn't. capacity ratio is worthless.
I gave how capacity is measured by the IEC and with reference to the US government Energy Star Program,
allowed for possible variances -
and merely used the capacity ratio as an indication.
10-01-2011, 05:34 AM   #23
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QuoteOriginally posted by UnknownVT Quote
I gave how capacity is measured by the IEC and with reference to the US government Energy Star Program,
allowed for possible variances -
and merely used the capacity ratio as an indication.
using capacity ratio only makes sense if the equation looks like this: 2500(charged)-0(discharged)/2000(charged)-0(discharged). That's not how batteries work.

10-01-2011, 05:55 AM   #24
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QuoteOriginally posted by abacus07 Quote
using capacity ratio only makes sense if the equation looks like this: 2500(charged)-0(discharged)/2000(charged)-0(discharged). That's not how batteries work.
Perhaps I am not understanding you.

Capacity should be from standard IEC testing taking the measurement
after a standard charge (1/10C for 16 hours)
then a rest of at least 1hour (but not more than 4 hours)
and a 0.2C discharge until the battery reaches 1.0V

My regular eneloop usage in the K-x does not go down quite as low as 1.0V -
but I do a discharge at 0.2C after they have been used in the in the K-x to shutdown -
the remaining capacity as indicated by the Maha C9000 using 400mA (=0.2C) discharge
is between 0mAh to about 70mAh -
which means the K-x manages to use almost all the capacity of the regular eneloop
from 0% to within about 3.5% - averages to about 1.75% remaining capacity -
so usage average of 98.25% capacity

Taking the worst case example of 70mAh remaining capacity
(the largest remaining capacity I measured over 2 years with 29 battery changes, using 3 sets) -
(for everything else being equal) then the equation is:

(2500-70)/(2000-70) = 2430/1930 = 1.259

ie: about 125.9% this is a difference of only 0.9%
from the indicative estimate using the simple capacity ratio 2500/2000 = 125% -
which should be well within experimental/measurement error.

However since not everything is equal - this is very dependent on how well the new eneloop XX maintain their operating voltage under-load - if for some reason they drop their voltage under-load more, then the K-x may "prematurely" shut down, when there may well be remaining capacity capable of powering less battery fussy devices.

Last edited by UnknownVT; 10-01-2011 at 06:26 AM.
10-01-2011, 07:47 AM   #25
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QuoteOriginally posted by UnknownVT Quote
which means the K-x manages to use almost all the capacity of the regular eneloop
It appears that I'm mistaken regarding this fact. I had no idea that the eneloops were able to keep the camera powered as they approached zero.

Please accept my apologies.
10-01-2011, 08:00 AM   #26
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QuoteOriginally posted by abacus07 Quote
It appears that I'm mistaken regarding this fact. I had no idea that the eneloops were able to keep the camera powered as they approached zero.
Please accept my apologies.
No problems at all -
you are absolutely correct though, that most other non-LSD NiMH rechargeable batteries do "give up the ghost" prematurely even when they may have substantial remaining capacity left for other less battery fussy devices (like flashguns or even other digital cameras)

Pentax (AA) dSLRs are notorious for being battery fussy - because they use the battery voltage under-load level for the level indicator and shutdown threshold.

That is why the maintenance of operating voltage under-load is so important -
and regular eneloops are particularly good at that - that is why they can power the Pentax dSLRs to almost "depletion" with almost no IEC remaining capacity left.

Let's hope that the new eneloop XX also manage to maintain good operating voltage under-load.

But like you said the only way to truly know is by comparing the XX with regular eneloops under the same conditions.

FWIW - on Amazon there is an eneloop XX review by NLee the Engineer (who normally writes very good reviews on batteries and chargers) - he says the eneloop XX test out to have higher than rated capacity
- but does not mention maintaining operating voltage under-load.

Last edited by UnknownVT; 10-01-2011 at 11:57 AM.
10-15-2011, 07:27 AM   #27
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UPDATE:

i have taken around 200 shots, including lots of flash and play with camera and battery icon is still orange. I never charged the batteries, out of the box.
10-15-2011, 08:27 AM   #28
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We purchased our eneloop 2000 mAh several years ago, and they have been excellent in our K100D. They don't come fully charged right out of the package.

We've found that even when the battery meter says that we are low on battery, the camera will often still operate for a good number more photos.
10-24-2011, 08:33 AM   #29
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UPDATE:

Batteries depleted after 600 shots, lots of flash, playing and astrophotos that require more power and processing...charged them, did 200 so far and icon is green.
10-24-2011, 08:55 AM   #30
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QuoteOriginally posted by theodoros1978 Quote
Batteries depleted after 600 shots, lots of flash, playing and astrophotos that require more power and processing.
Thanks for the update -
600 is a reliable average for regular eneloops -
but of course you played, used flash, and long exposures -
all those would likely lower the shot count.

Hopefully when you've settled into your normal shooting pattern the eneloop XX will show higher shot count. Please let us know.

My experience with regular enloops - (hopefully the percentages will apply) -

full Green lasts for about 1/3 (33%) usage -
half Orange first shows when there is still about 2/3 (66%) capacity left -
empty Red shows when there is about 1/6 (16.7%) capacity left.

(I am on K-x firmware version 1.01.00.07)

Last edited by UnknownVT; 10-24-2011 at 09:00 AM.
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