[cadmus]

only 150? what settings would do that? ShakeReducer? higher MPs? low light? flash? I don't know but i am all ears.

my "500" was 500 shots on my k-200d using low end alkalins. Kroger brand. I remember shooting photos on the microscope, one after another and it was 500 or more after each change. On-off would likely be less. Point is, if it was 50 photos for 4 duracells i would still have had to use duracells over litium ion proprietaries on most my work projects and most my vacations. In Patagonia i had access to electricity 3 days out of 45. On a boat I have less.

With the eneloops it was WAY more. Can't say for sure because i spend a great deal of time using the playback viewer. I know this is discussed on other threads as 1000-1500.

Not sure what you are suggesting with the car battery. That i charge from a car battery or carry a car battery with me? I have a car charger or dc->ac115v converter for both my work trucks. I have a solar array and marine battery bank on my mobile laboritory and most sailboats have this as well. But that energy would be reserved for navigation lights and important things. When I say "in the field" i am in wilderness, so no car batteries. Maybe when my kid hits the invincible teenage years i will make him carry a car battery, hehehehe. Either way, AA is easier.

And I plead with Pentax to keep a weather sealed AA DSLR on the market for those of us not near chargers.

---------- Post added 03-14-15 at 01:03 PM ----------

On a side note. Do you all feel the AA hand grip additions will always be available? As much as they are too bulky for outdoor and back country use they might be all i have in the years to come. I build fiberglass protection holsters for most my cameras and that would just be huge with a grip.

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Last edited by cadmus; 03-14-2015 at 12:10 PM.

[kadajawi]

The istDS didn't have SR. Didn't use flash. Few reviews. Barely used the screen. It was BAD. Maybe a bit more than 150, but less than 300 for sure. The batteries would have a lot of life left in them when used in a clock or remote control... I think the voltage just dropped below a level the camera could work with.

I was thinking of having a big battery on your boat at least. A big Li-Ion battery would also be possible... at least they are much lighter and smaller (for the capacity) than eneloops. You would have to plan ahead though.

Another possibility would be to rig up a charger that works with AA. Basically get a Li-Ion charger that works with 12V and USB apart from 110/220V, and build a way to use that charger with an AA source. An advantage would be you could really suck the AAs empty.

So you could have 2-3 Li-Ions for the camera, plus a big Li-Poly or Ion battery that gets charged when you do have electricity (car, hotel, ...). Then the AA contraption for emergencies. Charge the D-Li109 via big USB Li-Ion until that gives up, for the rest you can use AA to charge the D-Li109.

Optimal? Maybe not. But perhaps do able? And perhaps even lighter than the pure AA solution? How many shots do you do typically?

There is also the possibility that there will be a proper successor for the K-50, with AA support.

http://www.ianker.com/product/A1210011
For example. I use a Xiaomi 10400 mAh pack that can charge my D-Li90 a few times, and the D-Li90 packs a big punch, bigger than a set of eneloops for sure. I'd say at least 1500 photos? I've gotten more out of it... The disadvantage is the metal enclosure of the Xiaomi, that adds weight. One or two of those Anker should get you through a trip. Li-Ions have less problems with cold weather, low self discharge etc.

If I calculate it correctly there should be 8-9 charges of the D-Li90 in the Anker...

[cadmus]

Kadajawi, these are great ideas but they involve lots of stuff. Also, what little i remember from thermodynamics would suggest going from chemical to electrical to chemical to electrical might loose a lot of energy. thanks for trying to help. I might start a DIY post about modifying non AA pentaxes to have a AA powersource that is less bulky (and more sturdy) than a grip. If i do i will email you and ask that you participate, but it is off topic here.

[kadajawi]

It really depends... if a USB powerbank is enough to get you through the whole thing, then it's just the charger that takes USB, and the battery, and you are good to go. You do lose a bit converting back and forth, which is why I expect it to only do 8-9 instead of 9.5 or so charges. Still that's plenty.

I (personally) think it's on topic enough, given that it at least might take some anxiety from potential K-S1/2 buyers. The main reason why Pentax has went this route is probably the higher energy density Li-Ion batteries give.

I'll gladly participate in your new post, IIRC there have been various different efforts already in this forum as to using alternative power sources.

[cadmus]

The main reason why Pentax has went this route is probably the higher energy density Li-Ion batteries give.

Lithium Ion is Lithium Ion. Yeah it gets better with new technology but you can make it in a cylinder (50.5mm L x 14.5mmD) just as easy if not more easy than some shape that is incompatible with other uses or models. Please explain this "energy density" inherent in other shapes?

If you are not referring to the chemistry/membranes and just talking just geometry the difference is negligible. In fact, I have taken apart many odd shaped batteries and all were numerous cylindrical cells stacked inside.

It might be convenience for the design team, put in all the internal components and make whatever shape is left into a battery. I will give them credit for this.

Most likely they want to make you buy more things:
-proprietary batteries means you can not share across brands or products or models. You have to buy new batteries and chargers for EVERYTHING. Even when you are loyal to a brand you have to buy new batteries and chargers when you upgade.
-Proprietary batteries allow them to make products obsolete by no longer making the battery. You have to buy a new camera just because the batteries died and no one makes them anymore.
-Consumers who do not know better assume proprietary batteries mean it is more high tech. I do not understand this silliness but i have observed it with other products and had folks on this website say similar things. like proprietary electrons are faster or something?

[kadajawi]

Li-Poly batteries can be flat though. And I meant that the D-Li90 can go further with a full charge than 4 AA eneloops... despite the D-Li90 being maybe the size of 2 AA and weighting as much as 1-2 AA (haven't measured it). That is an advantage. And if you don't have eneloops or similar your AA experience is horrible. At least mine was. Even focusing was slower than when connected to the power brick.

I know there are rechargeable Li-Ion AAs, but they are hard to get, expensive and I'm not sure if they aren't too powerful for the camera.

Your argument with them being able to force you to buy new batteries would be valid if Pentax indeed did that. But they have been using 2 D-Li versions seemingly forever, and their cameras come with the charger included. There are also plenty of off-brand alternatives available.

[cadmus]

Your argument with them being able to force you to buy new batteries would be valid if Pentax indeed did that. But they have been using 2 D-Li versions seemingly forever

That is good to hear. (i see different numbers and assumed they are different shapes)
But it still doesn't work for me.
I don't understand how eneloops or other AAs are not keeping up, assuming they indeed hold less charge PER GRAM.
Regardless, there is no shortage of space in a SLR body. The k-01 proved that anything smaller than we are using now is neither ergonomic nor functional.

If, per gram, the eneloops are not keeping up, how about the high end disposable lithiums?

I am not totally sold on this but since i do not know the dimentions of the Dli-109 nor the mass I really can not argue.

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Last edited by cadmus; 03-15-2015 at 08:57 AM.

[kadajawi]

That is good to hear. (i see different numbers and assumed they are different shapes)
But it still doesn't work for me.
I don't understand how eneloops or other AAs are not keeping up, assuming they indeed hold less charge PER GRAM.
Regardless, there is no shortage of space in a SLR body. The k-01 proved that anything smaller than we are using now is neither ergonomic nor functional.

If, per gram, the eneloops are not keeping up, how about the high end disposable lithiums?

I am not totally sold on this but since i do not know the dimentions of the Dli-109 nor the mass I really can not argue.

If I recall correctly there is the D-Li109 (K-r, K-30, K-50, K-500, K-S1, K-S2, and perhaps a few more... though before the K-r Pentax used AA) and the D-Li90 (K-7, K-5, K-3, 645D and I suppose 645Z). That's all. I think that's quite reasonable, though it would be nice to see the bigger D-Li90 in the lower end cameras.

The K-S1 and K-S2 do have a shortage of space it seems, which is why AA was dropped. I suspect they filled the grip with other stuff.

High end disposable lithiums are great... but IIRC they cost a lot, and availability isn't great.

D-Li109:
Output Voltage 7.4V (approx) Dimensions 2.2 x 1.4 x 0.6" (56.6 x 36.1 x 14.4mm) Weight 2 oz (57g)
D-Li90 (not the original Pentax though, but should be close enough):
Output Voltage 7.4 V Watt-Hours 13.32 Wh Dimensions HxWxD: 2.23 x 1.53 x 0.83" (5.7 x 3.9 x 2.1 cm) Weight 2.9 oz (82.2 g)
The output voltage of a set of 4 AAs is quite a bit lower, and it's not so stable (eneloops fixed that a bit). It's 1.2 V per battery, so we get up to 4.8 V instead of 7.4 V. That may be another reason why DSLRs are moving away from AA? 4 eneloops without adapter weight 107g, they have 2,28 Wh each. 9.12 Wh. That's measured drawing 100 mA though. At 500 mA, which is still less than my K-5 would draw when recording a video (I can reasonably get around 2 hours of video out of the battery, while it takes 3 hours and 20 minutes to discharge the eneloops at 500 mA, they only have 2.07 Wh. 8.28 Wh. And the average voltage is 1.14 V. and if the eneloop is stressed at 1000 mA it drops to 1.05 V and 1.79 Wh. 7.16 Wh that would be.

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Please correct me if I made a mistake... I suppose the draw per battery is lower because it's spread out? I can't remember anything from electrical engineering classes...

But it looks to me like DSLRs have outgrown AA cells, unless they move to 6 AAs, and even then, Li-Ion cells are simply better. If anything, the 14500 might make sense, if it fits and the camera can handle it... the problem is that they have 3.7 V each, so either you make it only work with AA, or you make it only work with 14500, or add some additional electronics.

AA-powered battery pack with USB port for output?
These things are made, though not all of them are good.

[cadmus]

Before we get off track, has Steve.Ledger responded to any our responses?

[kadajawi]

Before we get off track, has Steve.Ledger responded to any our responses?

Nope. Maybe he hasn't been here again, or he sees your point.

The problem is that AAs give you a sense of "everything will be fine, no matter what happens". A Li-Ion will probably do the job for most (I believe you are an exception), but having a backup plan is reassuring.

The ability to charge in camera via USB should calm down many, IMHO. A battery grip/option to charge the internal battery via AA the rest. Like... you put the AA in the battery grip (connected to the camera) at night, push a button and the next morning the Li-Ion is full, so you don't have to use the grip if you don't want to.

At least the higher end Pentaxes should have these options.

Edit: Just saw this. Quite off topic, but looks really nice and useful:
http://www.goalzero.com/mobile/p/133/Guide-10-Plus-Battery-Pack

It can be used to charge USB devices via AAs, or AAs via USB.