Hello,
Has anyone tried to make an external battery pack for the sd780? I had attempted to but it seems that this camera is very picky on the correct voltage supplied.
I have this awesome Polarmate Li-Ion battery pack that outputs 5v (more like 5.1v). The Canon ACK-DC10 AC adapter for this cam seems to output 4.2v but not sure of the exact output as I don't have one of these. I did hack up one of the DR-10 DC Couplers and put 2 diode in it to drop the voltage from 5v down to ~4.2v. It did work but the coupler got a little too warm for my taste (because of the diodes). I then tried to take the same diodes and place them inline outside of the camera but this did NOT work. The cam would turn on OK and show a preview but when I went to focus for a shot, the lens would come half way out and shut off. I also tried a few different voltages:
3.7 - 4.1v, the cam would not even turn on
4.2 - 4.6v, the cam would turn on but would shut off when trying to focus
Maybe the sweet spot is somewhere between 4.1 - 4.2v.
The NB-4L battery for this cam has a full charge of around 4.1v and drops with usage. I think that the cam will shut off when the battery reaches ~3.7v
Do any of you have any ideas, help or pointers that might be helpful in creating a nice external battery pack for this cam? It's a very nice camera and would be awesome to have more juice for extended time lapse sessions. It doesn't go very long with the NB-4L
Thanks!