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08-22-2007, 07:31 AM   #16
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It's funny how we all have different experiences. I have been using Energizer 2500mah batteries for my K100 and still get about 700 shots per charge (no flash use) after about 9 months.

I think the slow chargers do a better job at topping up the batteries than the fast ones though. I use a 10 hour charger and have no issues.

08-22-2007, 11:14 AM   #17
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I've been using Uniross Hybrios for about 6 months in my K100D. They're great, ideal in fact. I can get about 5-600 shots over a 3 week period, which is my average shooting rate I suppose, and if I put in another set that I charged a few weeks ago, they work fine for the same number of shots. That sort of behaviour makes them very easy to live with. I use a 3yr old Uniross smart charger that charges in pairs at 1A, so takes about 2 hrs for completely flat batteries which NiMh never are when taken out of a K100D so 1.5hrs would be more like the normal charge time. A set of Energizer 2500mAh I have are better though if I charge them and heavily use the camera all day long, I've had 900 shots on that basis.
08-22-2007, 01:55 PM   #18
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I use whatever... I have some energizer 2500mah and some off-brand 2700mah I got from

I have NEVER had problems, and here's why:

I'm an R/C plane hobbyist, and I use my very expensive computer controlled programmable charger for my batteries. Even the expensive chargers made specifically for the brand of battery you might buy are not as good as a hobby chargers peak detection and conditioning programming.
08-22-2007, 02:52 PM   #19
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Eneloops, New Sony NiMH, and CRV3

I usually keep a set in the camera, one set as a spare, and 2 CRV3's as a backup. The Eneloops and the new Sony NiMH batteries do not have the self discharge problem of the older formulas, and they do give lots of images per charge (over 500) in both my K100d and ist D cameras (the ist D does go longer on a charge).

The CRV3's long shelf life and ability to handle in excess of 2000 images makes them ideal as a vacation set or backup.


08-22-2007, 03:11 PM   #20
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Hi Guys,
I'm stalking a K100D atm so this thread is interesting
There is one only in my city
They have a set of good 2500s and a one hr charger thrown in.
Spose the 1 hr could be a good emergency charger ?
I think using my 12 hr charger would be easier on the batteries in the long run ?
08-22-2007, 03:42 PM   #21
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QuoteOriginally posted by Transit Quote
Hi Guys,
I'm stalking a K100D atm so this thread is interesting
There is one only in my city
They have a set of good 2500s and a one hr charger thrown in.
Spose the 1 hr could be a good emergency charger ?
I think using my 12 hr charger would be easier on the batteries in the long run ?
I read somewhere that slow chargers are easier on batteries but I can't remember where so don't quote me on it.
08-22-2007, 03:57 PM   #22
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I have been usng enelops for sometime with the DS, I can highly recommended them.
and I mostly shoot motorsport.....
08-22-2007, 08:12 PM   #23
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QuoteOriginally posted by arbutusq Quote
I read somewhere that slow chargers are easier on batteries but I can't remember where so don't quote me on it.
You are correct sir.

08-24-2007, 05:43 AM   #24
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I've been using Energizer 2100mAh for a few months with good results, about 500-600 shots. They lose charge in about 2 weeks, for that I keep a backup set of Eneloops and some Energizer lithiums as well.

There is a very noticeable increase in AF speed with the 1.5v batteries, but I haven't tested it in reality, the speed is comparable to the K10 but some people report bad focus accuracy.

I wish somebody'd sell a bulk pack of 80 lithiums for 30-40.
08-28-2007, 02:02 PM   #25
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First off, just fully discharging and recharging NiMH (let alone NiCD) does wonders. The rate of charge is less of a consideration in comparison.

Secondly, the biggest problem with NiMH is the lack of real-time current (not current-time), of which the Pentax K100D really sucks up. You need NiMH batteries that can provide well over 1A (and, ideally, up to 2A), and a lot of "cheap" ones just don't.

Third, here's my early July "super-blog" on the matter:
BS' Blog: Rechargeable Li-Ion is not Non-Rechargeable Lithium (e.g., Li-Mn, Li-Fe)
08-28-2007, 07:40 PM   #26
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They have a set of good 2500s and a one hr charger thrown in.
Spose the 1 hr could be a good emergency charger ?
I think using my 12 hr charger would be easier on the batteries in the long run ?
"1 hour charger" is normally one hour - for only 2 batteries. And yes, a slow charge is best for any battery.
09-03-2007, 09:56 AM   #27
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QuoteOriginally posted by arbutusq Quote
I read somewhere that slow chargers are easier on batteries but I can't remember where so don't quote me on it.
QuoteOriginally posted by matiki Quote
You are correct sir.
Although this may seem true - slow charging may not be the actual reason.

Rechargeable batteries have premature failures due to over-heating - which occures mostly during charging - and fast charging is very suseptible to over-heating.

However in the case of NiMH (the most common rechargeable used these days) - a slow recharge rate is not really optimum - as the end of charge is not easily detected - then comes the problem of over-charging - which again is not good for the battery. Of course one can argue that with a slow charge rate it takes longer to over-charge.......

I do bow to the battery experts here but it may be worthwhile looking at - specifically at their section on

Charging NiMH

about 2/3 down the page -

QUOTE: "Charging nickel-metal-hydride

Nickel-metal-hydride chargers require more complex electronics than nickel-cadmium systems. To begin with, nickel-metal-hydride produces a very small voltage drop at full charge and the NDV is almost non-existent at charge rates below 0.5C and elevated temperatures. Aging and degenerating cell match diminish the already minute voltage delta further. This makes full charge detection difficult.

A nickel-metal-hydride charger must respond to a voltage drop of 8-16mV per cell. Making the charger too sensitive may terminate the fast charge halfway through the charge due to voltage fluctuations and electrical noise. Most of today's nickel-metal-hydride chargers use a combination of NDV, rate-of-temperature-increase (dT/dt), temperature sensing and timeout timers. The charger utilizes whatever comes first to terminate the fast-charge.

Nickel-metal-hydride should be rapid charged rather than slow charged. Because of poor overcharge absorption, the trickle charge must be lower than that of nickel-cadmium and is usually around 0.05C. This explains why the original nickel-cadmium charger cannot be used nickel-metal-hydride.

It is difficult, if not impossible, to slow-charge a nickel-metal-hydride. At a C?rate of 0.1-0.3C, the voltage and temperature profiles fail to exhibit defined characteristics to measure the full charge state accurately and the charger must rely on a timer. Harmful overcharge can occur if a partially or fully charged battery is charged with a fixed timer. The same occurs if the battery has aged and can only hold 50 instead of 100% charge. Overcharge could occur even though the battery feels cool to the touch.

Lower-priced chargers may not apply a fully saturated charge. Some will indicate full-charge immediately after a voltage or temperature peak is reached. These chargers are commonly sold on the merit of short charge time and moderate price.

Simple Guidelines:

Avoid high temperature during charging. Discontinue the use of chargers that cook batteries.

A charger for nickel-metal-hydride can also accommodate nickel-cadmium, but not the other way around. A charger designed for nickel-cadmium would overcharge the nickel-metal-hydride battery.

nickel-based batteries prefer fast-charge. Lingering slow charges cause crystalline formation (memory).

nickel- and lithium-based batteries require different charge algorithms. The two chemistries can normally not be interchanged in the same charger.

If not used immediately, remove the battery from the charger and apply a topping-charge before use. Do not leave nickel-based battery in the charger for more than a few days, even if on trickle charge.
A well-designed charger is a reasonably complex device. Taking short cuts will cost the user in the long run. Choosing a well-engineered charger will return the investment in longer lasting and better performing batteries." END QUOTE

Back to the original question - primary lithium batteries (like the Energizer e2) do last longer - but they are not rechargeable and are expensive.

Most people recommend using NiMH rechargeables - normally the higher the capacity the better - however some people have found higher rates of failures of higher capacity NiMH (like 2500mAh) to the point where some people have preference for slightly lower capacitie like >2000 mAh - BUT these are not definitive - but fast chargers that fail to detect end of charge thus over-heating and over-charge may be the culprit.

More dying Energizer 2500's...

Duracell 2650 batteries dying

C/2 rate of charge for NiMH seems to be some kind of "optimum" (read section above) - it seems the lowest rate of charge where end of charge can be reliably detected, and with a functioning charger the charge is stopped or changed to true trickle charge for NiMH (ie: =< 0.05C).

However the main complaint of NiMH is their high self-discharge rate - often people return to thie cameras some months later to find the batteries flat.

The new LSD - Low Self-Discharge batteries appear to be gaining favor - eg: Sanyo eneloop, Ray-O-Vac Hybrid, Kodak Pre-Charged, Uniross Hybrio.

Apparently the Sanyo eneloops are different from the others. Eneloops have very slightly lower capacity (although the rating seems very accurate) - but seem to hold their charge longer. Eneloops are the most popular because of name recognition - but reports on others are all favorable - but beware these are all relatively new on the market.

My personal "strategy" is to use high capacity NiMH ~2500mAh when I know I have to shoot a lot over a short period of time and keep a set of LSD batteries (I use the Kodak Pre-Charged mainly because they are cheap) as back-up/spare.

If I am not going to use the camera for a while - I then keep the LSD/Kodak Pre-charged in the K100D.

Some references on LSD -

Eneloop Self Discharge study - CandlePowerForums

new Kodac "Pre Charged" NiMH batteries?
see posts #13 , #14 for comparison graphs of capacity between the Kodaks and the standard Duracell 2650mAh NiMH, and against the Uniross Hybrio (LSD).

Unknown Vincent Photos 2006
Unknown Vincent's Photos 2005
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Unknown Vincent Photos

Last edited by UnknownVT; 09-03-2007 at 10:48 PM. Reason: typos
09-03-2007, 12:00 PM   #28
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Sanyo Eneloops only.

Not the cheapest, but pays off already on the medium run.
Best there is.

09-03-2007, 01:54 PM   #29
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I've had very good experience with GP and Panasonic 2700 rechargeables. I have regular Uniross's (not hybrio) but they lose their charge ridiculously quickly (few days, a week tops). My record is 900+ shots with Panasonic ones. Since most of the times I carry backup set, I never worry about running out of juice. I do use expensive-ish slow charger though.
09-03-2007, 06:24 PM   #30
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Like Matiki, I'm an RCer as well....

Dear Fellow Pentax-ians:

The PIPE Here...and when I ordered my Pentax K100D (along with the kit lens and the DA 50-200mm telephoto) I got myself two quartets of the Thomas Distributing Sanyo 2700 mAH AA cells to power my K100D ...the link to them is at Sanyo 2700 mAh Rechargeable batteries - 2700mAh Industrial AA Rechargeable Battery .

Now, these are NOT the Eneloops, but they DO have that extra 700 mAH in them, that seems like it might comie in handy when using the flash a lot, espeically in a "fill-flash" mode outdoors.

Like "Matiki" who's already posted here, I'm an RCer as well, and I've got a pair of single output computer chip operated chargers that are likely very similar to what "Matiki" might have. Mine are the older, 2001-2002 vintage FMA SuperNova chargers, another, similar one that's currently in production is the popular Great Planes "Triton" unit.

Usually, with the earlier Sanyo NiMHs I've soldered together myself into four and eight cell battery "packs" to respectively operate the aircraft's (receiver & servos) and transmitters, I've had to "excer-cycle" NiMH battery packs to get them to their full capacity, with three complete charge & discharge cycles doing the job.

Using a set of four cell battery holders and connecting them up to one of my SuperNovas, I also tried this with the Sanyo 2700 cells I got from Thomas...

...and I was thankfully rewarded while TRYING to excer-cycle them, as the cells came right UP to full charge capacity, after only ONE cycling run.

Usually I set my SuperNovas in NiCad manually set mode (since many user's SuperNovas HAVE had troubles with charging NiMHs before, in the NiMH mode) for the NiMH cells I've got for my radio gear and now the K100D's cells, and I prefer to charge at a slow and steady C/8th charge rate while I'm charging NiMHs in the NiCad mode...and I wouldn't go any quicker than a C/6th to an absolute upper limit of C/4th of capacity when setting a charge current rate for NiMHs, when charging them in the NiCad manual mode on the SuperNovas.

Since I only got this camera last June, and my annual big photo weekend is coming up the weekend after Labor Day at Old Rhinebeck Aerodrome (for the HUGE RC Jamboree, pre-WW II RC Scale model fly-in that weekend) it is going to be interesting to see IF the Sanyo 2700s run out of "zap" before I could ever fill the 2 GB SanDisk SD card in my can hold something like a total of over 670 photos in full 6 MP best quality JPEG mode, and I'll have my chargers along for the ride to keep the Sanyos in good shape with an overnight charge at C/8th rate as I've been doing.

Hope this posting helps someone out...

Yours Sincerely,

The PIPE...!

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