In another forum I read (over at RedRockMicro), a fellow 5D2 enthusiast posted how to use Anton Bauer batteries on our camera!
He went all out with adjustable power and LED display and the whole 9 yards. He's got a Vimeo page about it at:
Custom Anton Bauer Battery Mount on Vimeo
and a write up at:
Index of /battery (http://www.cgllc.com/battery/)

It's a bit too rich for my blood, but all the important info seems to be there and he did such a fantastic job, it truly looks beautiful and professional.

As few of us know there are plenty of BP-945 analogue batteries with chargers available and I myself use those even on my Canon HV20, it lasts 8hours LCD incl 4hours rec time. And in my A1 it lasts about 6 hours too inc 3h rec time.

One can get that Chinese BP 945 6000mah battery and a charger for about $25. (eBay Store - mming2007: Camera Case Bag, Charger Adapter For Canon (http://stores.ebay.com/mming2007))

Now if you couple that with a SWIT S-7000C series canon BP battery mount bracket for £20 you are almost there. Better even with SWIT S-7200C battery adapter for Canon, but for £50. (Welcome to Proactive - Professional Broadcasting Equipment & Camcorder Packages from Sony, Canon & Panasonic (http://www.proav.co.uk))

Canon | DR-E6 DC Coupler | 3352B001 | B&H Photo Video (http://www.bhphotovideo.com/c/product/590425-REG/Canon_3352B001_DR_E6_DC_Coupler.html) so this coupled with a battery plate and appropriate plug socket will give a really sleek solution under or @ about $100 with battery and a charger considering current BP 945 Battery+Charger offerings on the eBay.
BP 945 high capacity batteries are as cheap as $10.

We have really good external powering option here at those prices.
I'm waiting my parts to come in so I could report the running times etc.

T

I redesigned the box to make it cheaper and more low profile.

I just got the quote for it and it will be $144 with the connectors and the switches. That doesn't include anything inside or the battery mount.

I had a thought though and I can fit either the AB mount or the IDX P-V2 mount. So I added mounting holes for both. Let me know if anyone likes this cause if I order more than one the price will go down.

Here is the drawing I did for it:

http://cgllc.com/battery/BATTERYV2.pdf

Test in red will be engraved and the box will be black powder coated

To power my camera, a secondary audio recorder and monitor, this looks ideal and wonderful.
Everything from one Dionic or Hytron, all day. How cool is that!
If the cost could be kept down, count me in!

Switronix already makes a product which takes the power tap (12v) and supplies 7v to a Canon camera through the battery port. This could be adapted to work with the Canon 5d AC adapter as well. The Switronix has a female power tap as well for plugging in 12v accessories.

Switronix Product Details (http://www.switronix.com/product_details.php?cmd=info&id=185)

yeah thats cool if you only need one or two things powered but having a rail mounted system with 4 variable 12v outs and a variable 7.4 out is pretty nice at least for my needs since I need to be able to power a HD monitor, SD Mix pre, audio recorder and light. Plus if I have ac avalible I can plug it into the wall so that I don't have a bunch of different power cables.

I'd buy a complete setup if you sold it John.

John,

The "Variable Outputs" is what makes this so attractive to me (besides having an "All-Day" battery that powers my entire rig). I will be able to use this power supply on anything I might have in the future.