Hey all,
Disclaimer: The following is information, you try this at your own risk, if you do things incorrectly and cook up your equipment, that's on you, always practice before you do something on your camera, and again, I'm not responsible if you do something, whether I made the mistake here or not, based on whatever you do. In other words, you're responsible for you if you try to play with electricity. If you're already confident with basic electrical components and concepts, this is an easy task for you and may be of interest!
I've been rigging all my outdoor imaging gear to run off pure DC, no AC or inverters, and the camera too needed to be put on a larger battery option. Instead of going the traditional deep cycle marine battery route weighing 60lbs or more plus all the frills and stuff, I decided to make it all run from separate Lithium Ion battery packs. There are very good ones out there that are inexpensive and will have your gear running all night for a session of imaging and recharges over-day while you wait for the next night. I run each device off a separate battery pack. I've had a lot of people ask how I made the cable and setup for the camera cheap, because official adapters for DC power for dSLR seem to be non-existent and/or extremely expensive. Also, buying a DC to AC inverter than just goes back to DC to your device is also costly, inefficient and has more gear to carry around (even though an inverter is useful for other things, like camping, etc).
Anyhow, here's a very inexpensive means to safely power your dSLR without soldering skills/tools. Everything can be bought online and I'll give links. I'll explain in simple terms what I'm doing.
First, why DC? Well, all your electronics are mostly made to run on DC with few exceptions. AC adapters are just AC with DC converters inline (that box in your cable). Inefficient and also often has noise patterns. This may not matter to every day shooting, but for dark long exposure night shooting (ie, astrophotography) it can matter to some. Instead of building around AC and inverters to get back to DC and using expensive and/or heavy items, I went for an all-DC approach, using inexpensive parts, DIY cabling, and lithium power packs for light portable weight with long duration of energy availability. Also, most DC sources are 12v, and your camera doesn't like that, it likes something closer to 7V, usually between 7.2v and 7.6v is a normal range for Canon batteries (just look at all your batteries, see a common value, it doesn't have to be exact--the important thing is to be near an average, not way above, so not 9v and now way below, like 5v). Canon batteries tend to be around 7.xv so I went with 7.5v because it's available and works for all my Canon's.
Disclaimer: I'm in no way affiliated with any venders that I may link to, in order to show you the items I'm using and their costs.
Tools & Equipment:
Wire Cutter/Stripper/Crimper - Sky is the limit here, there are so many kinds. Basically just something to cut and strip basic electrical wire.
Electrical Tape - There's all kinds, just get whatever, you probably already have some.
Multi-meter - Not required, but I highly recommend it. When splicing wires and playing with this, it's good to be 100% positive (get it!?) you know which wire is which. These are dirt cheap.
Items to be Used:
Dummy Battery with Female DC Coupler (5.5 x 2.1 size coupler) - Get a cheap one off ebay, don't fret quality, it's just a +/- wire in a box! Remember the battery make is specific to models of cameras, physical size and all. So get the right one by model number. In this DIY demo, I'm doing it with a 7D so I'm using a dummy LP-E6 battery (which works for 7D, 70D, 60D, 6D, 5D3, etc). Here's an example of a cheap one that I'm talking about: LINK
, it will work, but the camera may "fuss" about it not having a known battery inside it. The remedy? Get a dummy battery with a decoder chip, it fools the camera into thinking it's a legit battery. I used LanParte's: LINK. Obviously it's more expensive, but, it works flawlessly and reports as a proper battery to the camera, so no fuss, and no weird messages, for $35.
DC Coupled Cables (5.5 x 2.1 size couplers; male to male) (2 pack) - I get these because they're cheap. You can get them longer, shorter, cheaper, right angle, straight, etc. This is up to you. There's no right or wrong way. I stress the size 5.5 x 2.1 though because it's a standard and will use zero adapters down the line with other things, so it's very universal. I used a few of these: LINK. This is the only cable you have to cut & splice by the way!
Buck Voltage Reducer - This is the most crucial thing, a little buck converter. They're cheap and pre-set. You can variable buck converters that have attenuation where you can measure the voltage and step it down to whatever you want with a bolt that you turn. I went with a pre-set buck so that I didn't have to fool with all that. I know I need 7.5v output, so that's what I got. A basic 12v to 7.5v buck reducer converter. Again, already setup, set to the proper voltage step down, pre-stripped wires, color coded and labeled so you know what is what and which end goes to where. I bought this one: DROK 12V to 7.5V Buck.
External Battery Pack - There are so many options for this, but I went with lithium ion 12V 6amp capable battery packs. I specifically like the inexpensive Talentcell packs. They have 12v 6AH, 12V 8.3AH and 12V 11AH options for $30, $50 and $65 respectively. Any are much much more potent than your little battery, and will last for hours. I generally use the 6 amp hour one for constant use. When I'm doing extremely long non-stop long exposure sessions, I use the larger capacity ones though. I think the 12V 8.3AH at $50 is the best bang for buck: LINK. Get what is right for you. Any other battery will work too. Just be careful of the output ratings, you want 12v DC and pay attention to the output amps and make sure the amp hours (or milliamp hours) are rated at 12v and not 5v or something. You want honest numbers. Talentcell shows honest numbers by the way (well as honest as can be expected these days). Note, these models have 12v and 9v output, you will want to use the 12v output only for this! If you use the 6AH version of the battery, it only has 12v output so nothing to mix up there.
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The only thing we really need to do, is take a single male to male DC cable and splice in the buck reducer converter into it, so that one side inputs 12v from a 12v source, and the buck will output 7.5v to the other end. This is the heart & soul of everything that we're doing. The rest just plugs in!
Here's what we're looking at:
IMG_9691 by Martin Wise, on FlickrSo for this, we only need the wire cutter/stripper, electrical tape, the male dc to male dc cable, a multi-meter is highly suggested and the buck converter.
Start by cutting your dc cable where ever you want. I did it closer to one side, to keep the buck converter near the battery (and less weight on the cable dangling else where!). Then gently strip some wire sheath away and expose the wires inside. They may or may not be color coded or marked. This is why a multi-meter is handy.
IMG_9692 by Martin Wise, on FlickrMy wires on the DC cable were not color coded or marked. One wire had a white stripe down it, but that could mean anything! So I plugged it into my battery and turned it on, and used my multi-meter to test the leads. When measuring DC power, you will get the same voltage both ways, but one coupling will be positive and one negative. So in this case, I found that the white stripped wire was my positive lead, because it read + 12v, where as if I reversed the contacts, I got -12v which meant it was backwards. So to get it right, just make sure your final voltage reading is a positive number, not negative, and that's how you know the positive wire with voltage is correct from your multi-meter. Get it right the first time, you don't want to undo this later if you mixed it up! And turn off the battery when you're done!
Once I figured out which was positive & negative for sure, via the multi-meter, I simply put the positive wire from the DC cable to the positive wire of the Buck reducer/converter's input side (the 12v intput side), see the image, it's very easy to figure out, but essential to get this right the first time. I didn't do anything special to combine the wires, just put them together and twist. I then just tape them up with electrical tape and squeeze out any air I can and seal it up.
IMG_9694 by Martin Wise, on FlickrHere's one side of the cable completed, the 12v input side. All that is left, is to add the output side to the Buck reducer, which will be the 7.5v side.
IMG_9695 by Martin Wise, on FlickrBefore I continue, I want to make sure my Buck is actually working and is stable, to do so, I use my multi-meter. If you wired it correctly, it will be outputting the rated output voltage. In this case, 7.5v. So I simply touched the positive & negative wires with the appropriate multi-meter leads and it reads the voltage back to me: positive 7.5v. Specifically note, it's positive, not negative! That way we know for sure the positive marked wire is actually positive.
IMG_9696 by Martin Wise, on FlickrLastly, I just twist the other end of the cable wire leads to the Buck just like the other side, positive to positive, negative to negative. Again, I knew which was positive because I tested it on the multi-meter and my unmarked/uncolored cable on DC coupler had a white stripe on my positive wire. I still tested it to be sure. Once all was ready, I twisted them together, and taped them up and sealed. Cable done! Nothing fancy to look at, but it does the job, is safe, and takes a 12v source down to a 7.5v source, and is now camera safe and friendly!
IMG_9697 by Martin Wise, on FlickrAnd here's the dummy battery in the camera, attached to the new cable, and on the external battery.
IMG_9705 by Martin Wise, on FlickrMoment of truth, we turn it on. The 7D powers on great, no complaints, thinks it has a battery in there, and I turned on Live View so you can see it functioning and would continue to function, so I left it on a while. Works great. Tethers great, and is now fully externally powered by a much higher capacity external battery. I used a little $30 TalentCell 12v 6000mah (6AH) battery here for the test. For imaging, I use the 12v 8.3AH battery for more capacity.
IMG_9703 by Martin Wise, on FlickrThis method applies to all cameras really, just make sure and get your voltage correct (too much will do bad things, too little will not even turn on) for your series of cameras. And make sure you get the right dummy battery and life is easier with a decoder chip in your dummy battery so your camera doesn't freak out that you're doing something without a chipped battery (did you even know they cared? They do!).
The above achieves 2~3 hours of imaging on the smaller battery in normal temperatures in Florida. I get 5 hours out of the larger battery capacities in the field.
Clear skies!
Very best,
And, he's great with all diy electrical projects.
