DIY: Build Your Own Flash Battery Pack: PART 1

Nice work, Vermin87. I think it's a good idea to add the switch, since it will prevent reverse charging on the battery pack.

To make a note on the AC adaptor, could put a 6V regulator or a zener diode to keep it at 6V.

I am more interested in a HV pack. I have tried to put a Sunpak HV pack to be used on a vivitar flash, but haven't really tried to do that on a Canon flash yet. Does anyone tried such experiment?

mbellot wrote in post #3245102
Since you already had it wired for barrel positive it seemed easiest (less work) to just leave it that way.

To do it with center pin positive you would hook the red from the internal battery and orange from the flash circuit to the center pin and then put the black from the internal battery to the switch contact and the black from the flash circuit to the barrel contact.

With the jack wired up safely now I'd say put five fully charged NiMH batteries in series and check the voltage.

As long as you are below ~ 6.4 volts (standard alkaline batteries can have an initial voltage as high as 1.6v, so four would be 6.4 volts) you should be safe to use the five battery version. If you are over 6.5 volts I would stick with packs of four.

When a NiMH battery is fully charged, the voltage can be as high as "almost" 1.4V, so it would be very close to 7V with 5 cells in series.

Vermin,

I know it has been a while since the posting of this message, but I was wondering if you have any insights now that it has been a while. Also, I was curious if you found any better solutions after the DIY project. I know for me it seems like as soon as I decide to go in one direction, a slew of better choices pop up even though I can't take advantage of them.

Finally, I was wondering if you are interested in providing a service of making these changes to other people's flash units.

You know I saw something like this done to a 580EX too, and after seeing that and thinking about how it might ruin my flash I decided to just do it right in the first place and bought a CP-E4 and called it a day. Too risky for me.

ben_r_ wrote in post #4808925
You know I saw something like this done to a 580EX too, and after seeing that and thinking about how it might ruin my flash I decided to just do it right in the first place and bought a CP-E4 and called it a day. Too risky for me.

The problem is the CP-E4 is for the 580. I have a Sigma. I have considered selling my Sigma and my Canon 420 EX to buy a 580. But I haven't done that. Yet. Actually, right now I am inventorying my stuff and picking that which I will keep. The rest is going up for sale. I plan on selling. A few backpacks, a Canon 70-200L 2.8, Canon 1.4 and 2.0 extenders, a Tokina 28x70 2.8, a Tamron 28-300, a tripod and ball head. Plus off course the Canon 420 EX.

I figure those things ought raise enough to cover a new lens, some expenses on my upcoming visit to London and cleaning up some outstanding debt.

hoghunter wrote in post #4809083
The problem is the CP-E4 is for the 580. I have a Sigma. I have considered selling my Sigma and my Canon 420 EX to buy a 580. But I haven't done that. Yet. Actually, right now I am inventorying my stuff and picking that which I will keep. The rest is going up for sale. I plan on selling. A few backpacks, a Canon 70-200L 2.8, Canon 1.4 and 2.0 extenders, a Tokina 28x70 2.8, a Tamron 28-300, a tripod and ball head. Plus off course the Canon 420 EX.

I figure those things ought raise enough to cover a new lens, some expenses on my upcoming visit to London and cleaning up some outstanding debt.

Hey! Sounds like a good plan to me!

hoghunter wrote in post #4808622
Vermin,

I know it has been a while since the posting of this message, but I was wondering if you have any insights now that it has been a while. Also, I was curious if you found any better solutions after the DIY project. I know for me it seems like as soon as I decide to go in one direction, a slew of better choices pop up even though I can't take advantage of them.

Finally, I was wondering if you are interested in providing a service of making these changes to other people's flash units.

Hey Hoghunter,

Yeah, It's been almost a year, I think, since I tried this mod. It was actually pretty successful. I determined that my 5-cell NiMH pack recycles almost a full second faster than the 4 cells in the flash itself. I've actually been able to use up to 8 volts with improved performance and without failure, but it seemed too risky to continue using it at that level. I haven't seen much need to use my flash so extensively for me to merit building my 5-cell pack (It's just been tested, not completed). The in-flash batteries are fine for me at the moment.

If I were to improve upon this design, I wouldn't use NiMH's anymore. I'd invest in a 6V Sealed-lead-acid battery and call it a day. I don't think I'd need to change anything on the flash itself...just the battery pack. Better solutions for the Sigma Super? None that I've found. Faster recycling time means higher voltage and less internal resistance, and the only way to really do it is to use a battery pack.

As for doing this modification for others, I can in no ways say that my soldering skills are professional. I took one soldering class my freshman year of College, and since then, I just do random projects here and there. Most of the time, I end up melting some of the plastic shells of whatever I'm working on, so maybe me doing it isn't the best idea.

http://www.youtube.com​/watch?v=Wx3G21bN94o

Me testing (TESTING!!) this idea. (SLA battery)

L

Have you applied this to a 580 yet?

I've made myself some battery packs that work just fine and you don't have to worry about re-wiring your flash... check out this DIY video I give step by step instructions on how to build it.