On a somewhat related note, I've been trying to dig up the number of shots a K10D/K20D can average on a charge of it's batteries. Searching the forum for batteries returns a list longer than the number of high quality lenses I'll never be able to afford, so I thought I might ask here. The reason I'm asking is because on another forum,
Digital Photography School - Digital Photography Tips for You, there was a long discussion on batteries and I took the time to work out the actual cost of ownership over a few years on rechargeable versus nonrechargeable batteries. Since I've been contemplating the differences between a K200D and a K10D or K20D, I thought I might run similar numbers for a comparison between rechargeables AA and the proprietary battery.
That discussion was here:
Fully charged - Part one - Digital Photography School
If anyone is interested. From some quick research I did this morning, it looks like expected life capacity of a Lithium-ion battery is between 300 to 500 charges before significant charge ghosting starts happening. That's about half the life expectancy of what a quality set of NiMH with a halfway decent charger would expect, but if the Lithium-ion batteries can take significantly more than double the shots compared to a set of AA, then clearly they still win in the long run from a purely cost based perspective.