Trying to run my sony Cybershot from an external 12V supply. Need help

Background:

I am currently trying to build a housing that will turn my Sony DSC W-55 Cybershot Camera into a time lapse camera (Automatically take a photo every X Seconds for an extended period of time).

I have already built the enclosure that houses the camera, circuit board and actuator that presses the shutter release button ever 15sec. (Adjustable). Pictures below

Problem:

I Need to run the camera for very long periods of time (current baseline is >8hr, but indefinately would be nice). The camera uses a Sony G-Type Li-Ion Battery that does not provide the runtime I need for this application, so I am trying to hook the camera up to an external supply. The battery has three terminals as follows

[+] = ~3.9V    (No surprise here)
[C] = 3V         (This is weird)
[-]  = 0V

I accepted that the extra terminal was strange, but figured it would not be hard to simulate.

I used an LM317 Adj. Voltage regulator to simulate the 3.7V [+] Terminal and a voltage divider off of the 3.7V bus to get the 3V required for the [C] terminal. I double checked everything and plugged it in with no success, the camera will not turn on.

My question is, what smarts are in the battery that I need to simulate, or is there something wrong with my current set-up. Any help will be appreciated.

Thanks,

John