For long, long time lapse sequences with my EOS-7D, I have adapted an "Ultra Capacity High Quality 33600mAh Portable Charger External Battery Pack" from Amazon:
http://www.amazon.com/Capacity-33600mAh-Portable-External-Notebooks/dp/B0063KXZQ2/ref=sr_1_2?ie=UTF8&qid=1378231213&sr=8-2&keywords=Ultra+Capacity+High+Quality+33600mAh+Portable+Charger

I modified an aftermarket battery grip:
http://www.amazon.com/Neewer-Vertical-BATTERY-DIGITAL-CAMERA/dp/B003Z6R33I/ref=sr_1_sc_1?s=electronics&ie=UTF8&qid=1378231431&sr=1-1-spell&keywords=neewer+battery+grip+for+cannon+7d

Using a "LM2596 DC-DC Buck Converter Step Down Module"
http://www.amazon.com/LM2596-Converter-Module-Supply-1-23V-30V/dp/B008BHAOQO/ref=sr_1_1?s=electronics&ie=UTF8&qid=1378231503&sr=1-1&keywords=buck+converter+step+down

wired into a modified AA battery tray from the battery grip to step down the 12 volt battery pack output to 8.4 volts.

This setup gives me almost unlimited camera battery power, but also will provide simultaneous power to my ASUS Netbook. It has the potential for powering other devices that can run off of 12 to 19 volts in 5 steps. The Turcom battery pack also has a 5.1V USB output for charging many other peripherals like a cell phones, while it is powering the camera and Netbook.

(I have tried to post images but this server is a cranky sob that keeps crashing, although I am following the size guidelines.)
You can look at my pictures here:
http://www.flickr.com/photos/35376408@N02/9667200476/
http://www.flickr.com/photos/35376408@N02/9663968621/in/photostream/
http://www.flickr.com/photos/35376408@N02/9663968815/in/photostream/
http://www.flickr.com/photos/35376408@N02/9663969369/in/photostream/
http://www.flickr.com/photos/35376408@N02/9667201708/in/photostream/

Thats a nice conversion. I've never seen a voltage converter housed in the battery grip before. Nice idea using the AA battery tray for holding the converter and nice that you thought to add a plug to it so the wires separate nicely for packing.

I've been using the lithium 8 volt packs from model cars to power my 5D2 directly via a fake battery in the camera. That requires no converter but doesn't give me 12 volts to power a laptop. I'm planning on getting GBTimelapse, which would need the laptop, so maybe I'll build something like this to run the laptop and camera together from one battery.

Thats one very large capacity, very flat battery by the way. Thanks for the link to it. Its going to be a lot easier to fit in somewhere than the model car battery plus another batt for the laptop.

Thanks.
You may be interested that the battery grip automatically reports to the camera that the adapter I have kluged is a BG6 battery pack, which makes the camera battery life gauge work properly. With this kind of setup the gauge will, after a very long time, report that the Turcom battery pack is running low.

There is a battery grip like mine available for the 5D2 at Amazon, here:
http://www.amazon.com/PLR-Wireless-Battery-Intervalometer-Replaces/dp/B008MNLV8W/ref=sr_1_13?s=electronics&ie=UTF8&qid=1378313099&sr=1-13&keywords=canon+5d+mark+ii+battery+grip

My advice is do not buy the Polaroid grip. I have one for the 7D and it has proven to be unreliable. Maybe I got a lemon!

Another thing I want to point out is that the Turcom battery pack has several selectable output voltages, from 12v to 19v. My Netbook, for instance, takes a 19v input to run and recharge it. That is fundamentally why I used this particular voltage converter. It does not care about getting 12 volts input or 19 volts (or anything in between), it still puts out a smoothly regulated 8.4 volts. The converter is adjustable, so it can serve a wide range of voltage requirements. It will handle 3 amps of current.

Another thing is that the battery grip comes with two battery trays, so if you do this you will have the regular LP-E6 (one or two) without doing anything but changing the battery tray. I my implementation I did not provide for allowing the battery door to close, obviously because the power jack and cord sticks out. I find that is alright in the field. The cord sticking out is vulnerable however.

If you decide to try this, I will be happy to give you or anyone else any assistance I know how.

~David

That looks fantastic! Tiny battery pack with huge power, it seems. Good job!

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+5d

Thanks for the great write up. I can see a build in my future

Hank
hwright at live dot com

If you want to skip the battery grip part you can just get the AC adapter for the LP-E6s on eBay... comes with a DC connector... ($15/$20)

http://www.ebay.com/itm/Generic-Compact ... 41676f4e40

Just search for LP-E6 ac adapter on ebay... it's $5 less if you don't want the actual ac adapter and just the dummy battery with DC power cord.

The grip makes it look a bit neater because the voltage converter sits inside and it's nice and clean.

In answer to the rest of your questions, you can buy the parts on eBay or a local electronics store and solder them together.
You're pretty much going to have to use the step up/down module because you need to power the camera at 7.2 / 8V and all the packs output 5,9,12 etc...
Also you can use any other battery pack too of sufficient maH rating.

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

David,

Thank you for the details. The battery grip sounds like a nice clean solution. I'll give it a try.

Thanks again!

Hank

Great post , This is a very useful information , thanks for this post

Hi ddesousa, thanks a lot for sharing this solution with us.




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