
Re: Simple power solution?
nworker wrote:
David,
That looks like a great solution. I have a couple of implementation questions. I have a Canon 5D MIII.
1. It does not look like the battery pack has a cord to connect it to an AC outlet from looking at the amazon page. How do you charge the thing?
2. I see that you wired up the output from the battery pack to the modified battery tray using a female connector. Where did you get that part?
3. Will you share your wiring in the battery grip?
4. The link you provided for a batter grip on the 5D was a Polaroid, but you cautioned against them. What about this one?
http://www.amazon.com/Battery-Canon-Dig ... +cannon+5dThanks for the great write up. I can see a build in my future

Hank
hwright at live dot com
Dear Hank,
I think the 5D battery grip that you are referring to is fine, but I don't know for sure because I am working with a 7D. The Polaroid brand is not itself bad in my experience, it is just that I had trouble with the one I bought. As I said, maybe it's a lemon.
The female connector is a standard DC panel mount jack that fits 2.1 x 5.5mm power plugs, distributed by MCM Electronics, although they are widely available elsewhere. Ebay has all of these things. I simply like the free second-day shipping I get with my Amazon Prime account.
The wiring is simple: the voltage converter is marked + and - for input, + and - for output. I took the battery tray apart and re-routed the internal wiring so that I could attach it to the step-down buck converter. The jack is center pin positive. I have used just a drop of super glue to hold the converter in place, to prevent it from rattling around. It is very light weight, so nothing more robust or complicated is necessary.
The regular dummy battery shell that comes with the Canon AC adapter will work, in fact I have modified one myself. The buck converter I use will fit inside the shell if you carefully split it apart with an exacto knife or other fine blade. The contacts are small, but easily solderable with care. Then I use super glue to tack it back together again. It will then fit in the camera and allow you to connect a battery of any voltage up to 40V to it. Be sure to set the output to between 7.2 and 8.4 volts. I set mine to 8.4 volts. The camera (7D) will tolerate up to 9.0 volts in my experience.
I have recently revised my setup to make a battery grip tray into a "universal battery grip" by modifying a Canon LP-E6 Battery Pack shell, as described above, but with a female power jack built in to it instead of a cord and internally connected to the original battery's circuit board, the one with the chip on it. With that I can put it and a real LP-E6 battery into the tray so that I do not have to connect the external battery necessarily. When my LP-E6 "adapter" is installed, and the buck converter is set to 8.4 volts output, the external battery pack will charge the real LP-E6 battery. The camera reports two LP-E6 batteries and shows shutter count, and percent charge. Of course, when the battery pack is connected, both are always charged to 100%. In an emergency, or whenever I want, I can remove the "dummy" battery and simply use the fully charged real LP-E6 normally (the grip will work with only one battery in it).
All this is to accommodate a Tekkon Power ALL Plus MP3450 paired with a MP3450i in tandem (Tekkon makes the brackets to do this). That way I have 104 Ah (104000 mAh) of power available for running the camera, my netbook that is running GBTimelapseEOS, and a LED work light. The netbook can be playing muzak at the same time if I want.
As for sliders, I just bought a Kessler CineSlider and elecktraDRIVE
http://www.kesslercrane.com/product-p/100132.htm but haven't had a chance to use it yet. Wish me luck!
I hope I have answered your questions. Please ask if you have any more.
~David