Very interesting. Using 10% charge remaining as "low", that would give us about three weeks of "off" time. This tracking with anyone's experience?
I'm particularly interested in the SD/power-off figure. The card needs no power to maintain it's memory, so power should be shut off to it when the reader is off, which means there should not be a difference between the power off consumption with or without a card.
This might be a brand-specific card issue, since I've read that some don't respond to the "power off" command - so the Reader may be trying to power down the card but it isn't complying. Natch, could you try ten or twelve different brands? And memory sticks ?
Seriously, the only thing I could think to add to your measurements would be a "power off after one hour", just in case it's got a lower power mode it might drop into after some period of time. Probably unlikely, though.
It would have been nice to leave it on the shelf for a few months and not have the battery drop, but I guess that wasn't a design priority. For example, if they elected to keep time with the main microcontroller rather than a dedicated clock chip, that could keep hardware costs down, but raise standby power. (Just an example, I don't know if this is the case for this design.)
Depending on the issue it may very well be fixable via firmware, if Sony is convinced it's a problem, which they may not be.
Thanks for the info - definitely going in my "stuff" folder!