Jan Christian

DIY DC jack in 580ex Speedlite for external battery pack


I wanted to make an external battery pack but I didn’t want to use “dummy batteries” to connect it to the flash, I wanted a jack. Whenever I modify/make something I try to make it look as though it came like that from the factory, or could have. That was my goal for this, a clean install. I chose to mount the jack in place of the “bracket fitting,” which is next to the “external power source socket”. I don’t use flash brackets so I didn’t mind ditching the fitting. As far as I knew, no one had ever done this before so I had no idea if it would even fit, but I was confident I could make it fit. So I just started drilling…

Proceed at your own risk. Don’t blame me if you break something lol

I don’t have photos of the disassembly process (sorry!) but it’s only a few screws. First, remove the batteries. On the bottom of the flash are four screws that hold the base on. Remove these then the foot assembly should lift off. Disconnect the little wire harness. Now, looking from above, rotate the flash head 90 degrees. You’ll see four screws, two on each side. I did this many months ago so I’m going by memory but I think you only need to remove the two on the front half of the flash body. With the screws out, the flash body is only held together with little clips/tabs along the seam. WIth the battery door open, work it apart. This part takes a little finesse but it will come apart.

With the flash apart, you can get to work. The external power source socket screws in from behind its mounting plate. You don’t have to remove it but I did just so that it was easier to work with while drilling and whatnot. The following pictures explain how I mounted the jack. Cut the wires for the jack longer than you think they need to be as it’ll make routing them easier. I’m not sure which gauge wire I used but it wasn’t as thin as 26 AWG, probably more like 20 or 22 stranded.

installing the jack

To make room for the jack I had to file down the corner of the pcb, which I marked in blue. As long as you don’t file across any copper traces, it’s perfectly fine.


Solder the other ends of the wires to the appropriate battery tabs, as seen below, under the “+” and “-” markers. By appropriate, I mean make sure you stay consistent with your polarity; this jack should be wired the same as the jack on the battery pack and both ends of the cable need to be consistent.


wires soldered

The hardest part of this project was routing the wires so that the flash could be put back together. The tolerances are very tight so you have little room for new wires.

wire routing

flash bottom

Since you have the foot assembly off, now is a good time to add a 1/8″ jack for a wireless trigger if you haven’t already. This is much easier. Just drill the hole for the jack and connect the wires as shown. Again, make sure this jack is wired the same as the jack on the trigger itself.

wireless trigger jack

Here is the exterior, along with another flash I modded with a 1/8″ jack.

two modded flashes

Getting the flash back together is a little tedious but just be patient. Be sure to attach the battery door before you start to reassemble everything. Once it’s back together, it should look something like this.

finished DC jack

You can even reuse the rubber cover if you cut a hole in it, which gives it a cleaner look.

rubber cover

My next post will detail how to make the battery pack and cable that connects the pack to the flash. Stay tuned!


6 Responses to “DIY DC jack in 580ex Speedlite for external battery pack”

  1. ohlee Says:

    thanks very much! I’m wating for your next post.
    I tried to make make an external battery pack too.
    I wanted to use the external power source socket. So, I made a plug to fit the socket.
    and connected with battery pack, but It didn’t work. there is no any problem, but I don’t know..
    May I ask a Question?
    what’s wrong with me? What’s the problem? I don’t want screws out the flash but use the socket.
    Please let me tell the solution. thank you!

  2. Jan Says:

    Are you referring to the high voltage port seen here? I don’t have the schematic for this circuit so I didn’t want to mess with it and possibly fry the speedlite. That’s why I opted to tie in to the battery terminals. The high voltage port is made for the 8-AA battery packs offered by Canon, Nikon and others. Sorry I can’t help…

  3. Sean Says:

    Jan – Do you if this can be done to the Vivitar 285HV?

  4. Jan Says:

    yup, you can do this on any flash, you just have to tap into the battery terminals.

  5. Sean Says:

    I modified my Nikon SB28 but found there’s very little room for the DC jack. Can you please give me the part # and place where you ordered yours as it looks quite short and may be a better fit for the SB28. Thanks.

  6. Jan Says:

    Sean, I purchased it at a store in Maryland (http://www.baynesvilleelectronics.com/index2.ivnu) and don’t have a part number as it was picked from a bulk bin. You could probably email them with a link to this post and ask if they could sell and ship you the same jack(s). I bet they would, they’re very helpful.

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