[GaryM]

There are lithium AA's -
eg: Energizer e2 lithium AA
- these definitely last longer in the Pentax K100D (Super),
and some claim they do make operations faster.

But they are relatively expensive and non-rechargeable.

A 4-pack costs me less than $10, for over 1000 shots, and they have a shelf life measured in many years. I would call this the *least* expensive part of my photography.

[Marc Sabatella]

A 4-pack costs me less than $10, for over 1000 shots, and they have a shelf life measured in many years. I would call this the *least* expensive part of my photography.

I guess that depends on your usage. For many, 1000 shots is a typical week. So that $520 a year for batteries. You could build a nice lens collection on that...

[GaryM]

I guess that depends on your usage. For many, 1000 shots is a typical week. So that $520 a year for batteries. You could build a nice lens collection on that...

Heck, if I was shooting 52,000 shots a year I'd definitely be using rechargeables. With my workflow, however, it would be a full-time job just post-processing that many images. But my gear sometimes sits around for weeks between shoots, and it's nice to not have to worry about dead batteries when I do.

[RiceHigh]

Welcome to the World of Measurebators and I think you have done a nice job!

I just got a K20D, and felt it was focusing faster than my K200D... Unscientific testing indicates that I was right.

Methodology and results are on my blog. The quick rundown...

Using Tamron 70-200/2.8-

• K200D - 1.15 seconds
• K20D with half power showing on the battery gauge - 1.00 seconds
• K20D with a fresh battery - 0.84 seconds

focusing sound "histograms"

[Marc Sabatella]

Heck, if I was shooting 52,000 shots a year I'd definitely be using rechargeables. With my workflow, however, it would be a full-time job just post-processing that many images. But my gear sometimes sits around for weeks between shoots, and it's nice to not have to worry about dead batteries when I do.

I should mention I am not among those who shoot 1000 in a *typical* week (on vacation, I might come close, though). Probably more like 100-200 a week on average. So for me, buying non-rechargeable batteries might only cost $50-$100 or so a year. Still, that's $50-$100 more per year than I spend now. And Eneloops don't lose their charge when not used, so even if I went a couple of weeks without shooting (which never happens), I'd be OK.

[UnknownVT]

FWIW - I just finished using a set of eneloops and managed 837 shots - mostly without flash.

However those were charged some 5 months previously (they were carried as spares) and the duration of usage was over about 2 months - so basically at the end of the usage the eneloops were some 7 months from charge.

This shows that the eneloops managed to hold their charge, and more to the point maintained their voltage above the relatively high threshold cut-off of the K100D - whereas I had a set of Kodak Pre-Charged used about 3months from charge that lasted 347 shots to shut-down - however they still had about 44% of their capacity left (shown by discharge in a regulated flashlight) -
see Post #62 of eneloop vs. Kodak Pre-Charged Voltage Maintenance
Kodak Pre-Charged are otherwise excellent LSD rechargeables
(from more recent charge they lasted some 671 shots with quite a bit of flash usage)
- it's just for the Pentax K100D's unreasonably high threshold cut-off voltage the eneloops are more suitable - especially if the batteries are used some months after charge.

So with its ability to deliver the demanded current while maintaining the voltage better - I wonder if eneloops would make focussing better/quicker than regular NiMH and how much slower than lithiums.

[Stratman]

Eneloops and the Ray O Vac hybrids are the way to go as far as I'm concerned. I know the Lithium e2 Energizers last a long time, but they ain't very "earth" friendly. Once dead, you hafta get rid of em....