Ok, I had weird idea yesterday. In searching for batteries, I've found some larger battery packs that plug into a digital camera's DC IN port, and can mount using the same screw used by a tripod to the camera. Some of these packs don't appear to even have the power of the batteries I'm using based on the maH (Mili-amps per hour) rating, so I'm assuming the larger packs can put out power for a longer period at that rate.
So, I got to thinking of my Sony Camcorder and how I have a spare battery for it, and could I use that for my digital camera? Short answer would be yes, if it were 6v, but my Sony battery is rated at 7.2, and actually with a charge is over 8v. Ack!
I used to be very into electronics, but haven't done much in that area for years, and so I'm not able to really see an obvious (cheap/efficient) solution to this dilema. I know I can drop the power down to 6v using some resistors to create a voltage drop, but that will shorten the life of the battery. I know I can use a regulator and drop that down to 5v or 6v, but since the difference between vOut and vIn isn't but 2v or so, that complicates things further.
Any circuit I can think of would either waste that precious battery power, or wouldn't work with the voltage levels needed, or not be able to handle the current draw of the camera.
So, it looks like my Sony battery is out of the question, unless anyone out there has some thoughts on an efficient & cheap circuit that would do the job.
Now, I do know that some camcorders use 6v batteries, so I might just need to see if I can scrape up any of those. No need for fancy circuits there.