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07-01-2007, 01:47 PM   #1
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Which rechargable batteries for K100D?

I just picked up my new K100D from B&H Photo this morning and also bought a set of rechargable nickel-metal hydride 1.2V 2900mAh batteries. The camera manual shows 2500mAh batteries in their chart of battery types (see page 29.) Will using the 2900mAh batteries harm the camera?

Also, I have an unlimited supply of AA alkaline batteries (I work in TV and we toss out dozens of professional grade AA alkalines each day in the studio - they're used in our wireless headsets and mikes and they are changed twice a day whether they need to be or not - and we get to take the "used" ones home. Most of the time they have a full charge.) How well will these work in normal usage?

07-01-2007, 02:14 PM   #2
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QuoteOriginally posted by PrompterBob Quote
I just picked up my new K100D from B&H Photo this morning and also bought a set of rechargable nickel-metal hydride 1.2V 2900mAh batteries. The camera manual shows 2500mAh batteries in their chart of battery types (see page 29.) Will using the 2900mAh batteries harm the camera?
No.

QuoteOriginally posted by PrompterBob Quote
Also, I have an unlimited supply of AA alkaline batteries (I work in TV and we toss out dozens of professional grade AA alkalines each day in the studio - they're used in our wireless headsets and mikes and they are changed twice a day whether they need to be or not - and we get to take the "used" ones home. Most of the time they have a full charge.) How well will these work in normal usage?
They won't last long. ~50 shots.
07-01-2007, 02:18 PM   #3
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Anyone use Sanyo Eneloops? I've heard good things about them.
07-01-2007, 02:58 PM   #4
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Hi Bob,
Yes, I use Eneloops, as does the whole family. Between us we have three Pentax Dslr's running on Eneloops.
I give them the highest reccommendation possible....but I always have a set of Energiser Lithiums in either CRV3 format or AA in the travel bag as a back up.
Note that Eneloops get better/stronger after a few charges.... bit like me actually after a few reds
Cheers
Grant

07-01-2007, 04:29 PM   #5
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Bob,

Another vote for Eneloops. I have two sets, and am very happy with them. I use my regular NiMH batteries in my flash and my P&S camera. As far as the alkalines, while they are not ideal, they are fine as spare batteries. I usually keep a set as spares for the flash, and always have a set in my P&S camera bag as backups.
07-01-2007, 04:29 PM   #6
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QuoteOriginally posted by GWP Quote
Hi Bob,
Yes, I use Eneloops, as does the whole family. Between us we have three Pentax Dslr's running on Eneloops.
I give them the highest reccommendation possible....but I always have a set of Energiser Lithiums in either CRV3 format or AA in the travel bag as a back up.
Note that Eneloops get better/stronger after a few charges.... bit like me actually after a few reds
Cheers
Grant
Hi Grant! Any recommendations on charging and using them for maximum benefit. I'm going to Alaska in August and I ordered 12 batteries and a charger from eBay. I'll also take your advice and carry some Lithiums with me for emergencies.
07-01-2007, 07:27 PM   #7
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I first used cheap (about $8 for two) Kodak CRV3s when I got my K100D, and got just over 2500 shots. When those ran out, I happened to get some Energizer ones, which are about $16 for two ($15 if you look). These are running out at just under 2750 shots -- almost exactly 10% increase for almost twice the cost.
(Both cases, very little flash use and almost exclusively with the DA 40mm Limited lens.)


Next up, some Energizer AAs. Four of these come out to about $8, just like the cost of the Kodak CRV3s, and they're a lot easier to come by, so it'll be interesting to see how that comes out.
07-01-2007, 11:33 PM   #8
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QuoteOriginally posted by PrompterBob Quote
Hi Grant! Any recommendations on charging and using them for maximum benefit. I'm going to Alaska in August and I ordered 12 batteries and a charger from eBay. I'll also take your advice and carry some Lithiums with me for emergencies.
Hi Bob,
Eneloops are unique in that they can be used straight out of the pack, no charging required....and they can sit unused for weeks and not dis-charge to any great degree. Other re-chargeables are generally flat if left unused for, say a week or longer.

They will reach maximium potential after 3 or 4 charges. I have had mine for a year now and I seem to be using them more and charging them less. I would reccommend spending a bit more for a good charger, one that can dis-charge before charging.

Alaska hey....sounds good, look forward to the photog diary. We were supposed to do the Inside Passage last year, but our ship, the Queen of the North, sank the night before we were due to board.
Have a great time.
Grant

07-02-2007, 12:47 AM   #9
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I switched to Eneloops, sometime ago and WILL not go back to anything else.
07-02-2007, 01:51 AM   #10
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Energizer NiMH 2500mAh AA mainstay + Energizer Lithium AA backup

Most people swear by the Eneloops. NiMH AA batteries are very leaky, and the Eneloops may have very well addressed that. I don't know as I have never used them.

Understand that the "charge" in current-time ([m]Ah) is not measurable -- except by a full discharge/recharge. Also note that "charge" is also not a good indicator of how well the batteries will supply "real-time" current ([m]A). In fact, many "charge" ratings in current-time are based on providing real-time current well below the approximate 2A (2000mA) the K100D requires. Most devices try to gage "charge left" by measuring voltage drop, due to current drop, although that means batteries incapable of sufficient current in the device (and resulting voltage drop) never show "full." It's literally "ideal" - "sufficient" - "insufficient" -- hence the "full" - "half" - "none".

Alkaline current-time is often rated at only 0.1-0.5A (100-500mA), and they not only won't provide anywhere near the required current for the K100D -- showing up as "half" or "no" battery in the LCD and resulting in voltage drop (slower AF, etc...) -- but their usable "charge" drops to 1/3rd of their rated.

Cheap NiMH rechargeables have similar issues, unable to provide more than 1A, and show up has "half battery" in the LCD. This includes the various no-brand NiMH 2600mAh and All-Battery.COM brand "Tenergy" NiMH 2600mAh AA batteries. Those guys will show up "half" in the LCD after a full charge! It's clear they were designed for lower current apps than the K100D, really more of an "Alkaline replacement" than a true, 2A+ capable rechargeable. I also verified (with a LaCrosse 900 series) that they only charge to about 2,000-2,100mAh, well under their rating.

I use Energizer NiMH 2500mAh batteries with my K100D. I get 400-500 shots (half that if I use extensive flash) with full battery and solid AF motor response. Now I use a cheap (again, LaCrosse 900 series, $40 at Amazon) to full discharge/charge at 250/500mAh or 350/700mAh, and I typically get a resulting 2700mAh out of the batteries -- using the full discharge/charge which is the only way to get the real charge supplied to the batteries. I also make sure I keep sets that are discharged/charged every few weeks, but the combination works extremely well for myself.

E.g., I fired off 1,000 shots at an airshow using two (2) sets and the LCD was always "full" battery, with the AF/motor maintaining a solid run. When I got home, I did a discharge of both sets and they still had 1500-1700mAh in them, meaning those 400-500 shots only used 1000-1200mAh. That makes sense because as they drop towards 1000mAh, that's when the Energizers can't deliver adequate current for the K100D anymore, and I get half LCD.

I carry two to three (2-3) sets charged within the last few weeks. I make it a habit to recharge sets after I use them, and I use my K100D every few weeks, so I never have an issue with "leakage." I've never let them go more than a month, so the may very well not last as long.

BTW, do not rely on Alkaline AA batteries for your "backup." Get Energizer Lithium AAs ad your "backup." I always carry one (1) set so I can fire off the last few hundred shots should I ever shoot 1,000-1,500 shots and deplete all 2-3 of my NiMH sets. The great thing about Lithium batteries is that they just last, they don't degrade over years, so they are "always fresh" from the standpoint of being "ready-to-use." They can deliver a solid 2.8+A during the full lifespan, so they will drive the K100D until they are near dead (700+ shots, half that with flash). And virtually every store has Energizer Lithium AAs for $10 per 4-pack -- so you can always grab those when you're on-the-road and can't charge.

Last edited by bjsmith; 07-02-2007 at 01:59 AM.
07-02-2007, 04:55 AM   #11
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I'm also curious, the alkalines are rated as 1.5V whereas the NiMHs are usually 1.2V, does that mean the camera can handle a range of 4.8V to 6V?
07-02-2007, 07:54 AM   #12
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Energizer nh15-2500, L91 and E91 ...

QuoteOriginally posted by Kguru Quote
I'm also curious, the alkalines are rated as 1.5V whereas the NiMHs are usually 1.2V, does that mean the camera can handle a range of 4.8V to 6V?
Nominal voltage varies based on many factors. As a battery is unable to provide sufficient current, voltage will drop. Alkaline AA batteries rarely have a nominal voltage of 1.5V, especially not at the loads the K100D throws at it. They will also fail to provide anywhere near the "charge" (in mAh) as most are rated with a measly 100mA load.

NiMH AA batteries typically charge at an electric potential of 1.5V, discharge at least an electric potential of 1.2V. Depending on the quality of the NiMH batteries, they may or may not be capable at providing even 1.2V at the current being drawn. Here's the data on the Energizer 2500mAh:
http://data.energizer.com/PDFs/nh15-2500.pdf

As you will see, pulling 2.5A (2500mA) from the Energizers will see voltage drop below 1.2V after about 0.7-0.75 minutes. I.e., as the batteries drop under 1000mAh "charge left," you'll see the LCD drop to "half" battery as current drops below nominal. This almost matches my experience with the Energizers in the K100D, although I'm able to charge my nh15-2500 models to between 2600-2700mAh (as measured with a LaCrosse 900 series). Also note the performance for 1.25A (1250mA) is fairly similar and consistent, 1.2V or higher nominal for even beyond 1.5h, basically somewhere below 1000mAh "charge left" (possibly as low as 500mAh). The performance for 5A (5000mA) is rather dismal though, and consider the battery unable to support it at all.

Unfortunately, the data on the Energizer Lithium and Alkalines are not very helpful as they don't look beyond 0.5-1A (500-1000mA).
http://data.energizer.com/PDFs/l91.pdf
http://data.energizer.com/PDFs/E91.pdf

As you can see, although the Lithium has a nominal voltage of 1.5V, and clearly provides over 3000mAh, but that's based on only a 0.05A (50mA) current draw -- the specs are clearly aimed at Alkaline AA batteries. Now looking at the graph next to it on page 2 for just 1A (1000mA), we see it provides well under 1.4V from second 1, and drops to under 1.2V in about 2.25hr, giving you about 2250mAh useful overall. The E91 Akaline in the same graph barely gives you a half hour at 1A, just over 500mA, and everything I've read says a 2A draw just kills Alkalines for sub 400mAh -- 1/3rd their nominal, rated "charge" in current-time (which is typically done at only 0.1mA). BTW, from what I've seen in other other tests, Lithiums can still provide over 2000mAh of 1.2V+ for up to a 2.5-2.8A draw though.

So considering I get about 1500mAh+ "usable" at close to the 2A draw of the K100D out of my Energizer NiMH 2500mAh AA batteries, for about 400-500 shots without any flash (half that for regular use of flash), and I've done more than 400 shots now with Energizer Lithium AA batteries and they are still "full" and most likely going to give me 2000mAh+ and around 500-600 shots without any flash (half that for regular use of flash), and these numbers aren't fabricated.

As always, NiMH require "care and feeding." I.e., they are leaky, so they need to be charged regularly (I never got a full month), although Sanyo Eneloops are supposed to be far less leaky. They can also have a "memory effect" -- and the Sanyo Eneloops are no exception to that, with many people complaining they need a full 3-4 uses and recharges to reach their original charge capability. Using a charger with a full discharge-charge really helps, especially if you always and fully discharge your NiMHs when you take them out. I do this with my Energizer NiMH 2500mAh to great effect using a LaCrosse 900 series that are sub-$40 at Amazon.

The LaCrosse 900 series are not the best chargers compared to ones that cost $100+, and there are documented issues with using the 100/200mA discharge/charge where the Delta-V is so low the charger doesn't detect the batteries are full. But I don't use the full cycle/refresh of the charger (that's really only necessary for older NiCD), and just use the 250/500mA and 350/700mA discharge/charge cycles (there is also a 500/1000mA cycle, but I don't use it, it's worth the extra few hours to get a full discharge/charge -- I've had a miscycle when I've discharged that fast). Doing that keeps my Energizer NiMH 2500mAh batteries fresh, always up to a full 2600-2700mAh, and a solid, capable 2A+ output that the K100D requires.

As others will recommend, the Sanyo Eneloops seem to hold charges longer. But I still recommend the full discharge/charge cycle. Some quick chargers do this now, although most don't.
07-02-2007, 08:32 AM   #13
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QuoteOriginally posted by GWP Quote
Hi Bob,
Eneloops are unique in that they can be used straight out of the pack, no charging required....and they can sit unused for weeks and not dis-charge to any great degree. Other re-chargeables are generally flat if left unused for, say a week or longer.

They will reach maximium potential after 3 or 4 charges. I have had mine for a year now and I seem to be using them more and charging them less. I would reccommend spending a bit more for a good charger, one that can dis-charge before charging.

Alaska hey....sounds good, look forward to the photog diary. We were supposed to do the Inside Passage last year, but our ship, the Queen of the North, sank the night before we were due to board.
Have a great time.
Grant
Better it sank the night before boarding than the night after!

To keep in with the actual thread tpic, I too am using Eneloops. Bought 3 sets and charger shortly after I got my K100D for Christmas and discovered just how fast standard AA batts drained. :-( I've gotten great use out ofthe eneloops and have started using them in my older Canon A80 P&S also.

Jim
07-02-2007, 01:43 PM   #14
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QuoteOriginally posted by CycloneBandDad Quote
I too am using Eneloops. Bought 3 sets and charger shortly after I got my K100D for Christmas and discovered just how fast standard AA batts drained. :-( I've gotten great use out ofthe eneloops and have started using them in my older Canon A80 P&S also.Jim
Jim, you are so right. I went through a dozen AA batteries today shooting about 100 pictures - glad I don't pay for them. Can't wait for my Eneloops to come from Amazon.
07-02-2007, 02:07 PM   #15
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QuoteOriginally posted by GWP Quote
Other re-chargeables are generally flat if left unused for, say a week or longer.
Just FYI, I haven't let my Energizer NiMH 2500mAh batteries go more than 3 weeks without using, and I haven't lost any noticeable charge on them when I do.
The All-battery.COM/Tenergy junk, on the other hand, comes up "half" battery on a full charge (much less only charges to 2000-2100mAh, and not the 2600mAh they are rated).

QuoteOriginally posted by GWP Quote
I would reccommend spending a bit more for a good charger, one that can dis-charge before charging.
Most definitely agreed.
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