i've never seen the CP-E3 battery pack, but coming from electric model car racing...i can't imagine building a battery pack would be very complicated? has anyone tried? for those who have the CP-E3...is there anything special about the pack, aside from the 8 cells and the cord?
nope, that seems to be it. I also considered what your thinking. I just didnt have the time. If you end up doing a DIY, post up your process for everyone.
1dvsgti wrote:
i've never seen the CP-E3 battery pack, but coming from electric model car racing...i can't imagine building a battery pack would be very complicated? has anyone tried? for those who have the CP-E3...is there anything special about the pack, aside from the 8 cells and the cord?
thanks,
I'd be interested in one for the new 580 mk II. I wonder how hard it would be..... I think the hardest part would be figuring out how to make the plug (find a reasonable cost plug).....
I was under the impression that the CP-E3 has a highvoltage interface to the flash in order to enable quicker recycling, not just a dumb batterypack. You could always do like the example in mh2000's post though.
1dvsgti wrote:
i've never seen the CP-E3 battery pack, but coming from electric model car racing...i can't imagine building a battery pack would be very complicated? has anyone tried? for those who have the CP-E3...is there anything special about the pack, aside from the 8 cells and the cord?
Well, I don't know if you consider this special or obvious, but you'll need to match the voltage of the batteries. If you look at the AA connections, I think they use all four AAs in series for 1.5x4=6v. (At least, my SB-25 is wired like this) So... you can use fake battery connectors like another poster, but as far as the actual batteries go, if you want to use 8 AA cells you'll need to make two groups of 4. The groups of four are connected in series (positive of one battery connected to negative of another, and so on, and you'll be left with a virtual 6v battery with one + and one - terminal remaining at the ends) and then connect both groups of four in parallel to the flash's input power. (connect the positive sides from both of the smaller groups to the positive terminal on the flash, and the same for the negative)
Or you can use a native 6v battery like the other poster.
Be aware that Canon EX flashes are not diode protected against reverse voltage. They are protected from reverse voltage by the physical shape of the battery terminals. If the flash sees a reverse voltage for more than a moment, the circuitry controlling the head movement motor will be literally toasted.
Insert your homemade dummy batteries the wrong way and you will join my club.
Working from the Al Jacobs idea I went with a Quantum cable, 6v 4Ah SLA, and a Bescor charger. Plenty of power for my use on a 430ex. Read up on the difference between using the dedicated jack vs. the dummy battery method.
The way I understand it, the jack is for a high voltage and current source which bypasses the capacitors. The dummy battery method puts the capacitors between the powersource and the flash tube, requiring the caps to be charged enough before firing at the required output. So if you're shooting full power, dumping the caps completely, you have to wait a moment for them to recharge. Since I'm normally not shooting full power, but rather at 1/3 or so, I can keep up a respectable round of short bursts.
Through the jack your going hot to the tube, dumping as much current as the the battery pack can muster. If you lay into it, at full power, it doesn't stop you from melting the unit. My shooting partner using his pack has burned his 580 three times. Now, he wants me to set him up with my gizmo.
Anyway, you can build your own. Just Google DIY flash battery and read up.
petee_c wrote:
So is the CP-E3 (and CP-E4) just a battery holder for AA's?
Tell us more about your batteryholder....
thanks,
P
I'm not familiar with the CP-Ex.
I use 5 sub-C NiMH cells in series to give 6VDC. After a couple years of no problems, I inserted the dummy batteries (similar to those shown on page one of this thread) into the wrong places in my 550EX and as soon as I turned on the flash - POOF, it was toast.
Even for weddings that go into the wee small hours, I find two sets of 2500mA NiMH (per flash unit) are more than enough. The last wedding I did, I didn't even need to change them out of my 420 and my 550 didn't need the fresh set till quite late in the night. What are all you people shooting that makes these packs necessary? Or, is it just a matter of convenience to be able to use all 8 batteries at the same time?
I have 2 Al Jacobs battery packs and will soon add a 3rd. They are well built, Al is a great guy and stands behind his products 100%.
It seems a lot of people with 420 and 580 flashes have door issues. I ordered a spare door for each of mine and cut the hinges off. It still locks into place and is secure.
The original door also lost the hinges. I drilled a whole in the middle to run the quantum cable through. After threading the hole I put a dab of silicone to seal it up. Now I have a door for use with AA batteries and one for use with the battery packs. It works great.
I'm hard enough on the flashes w/o trying to put high power into them. I don't like how the canon power pack unbalances the camera and add weight to my hands. Also, you still have to have the AA's into to run the interface.
Lastly, I also had to learn the hard way to put marks on my dummy battery inserts. I didn't completely kill my 420 but I tried real hard...
cogitech wrote:
What are all you people shooting that makes these packs necessary? Or, is it just a matter of convenience to be able to use all 8 batteries at the same time?
I put around 2000 frames on the cards with plenty juice to spare. It's a remarkable improvement in firepower over AA NiHMs. Firing direct without a diffuser over a 30D & 35/1.4L M f5.6 1/15s - 1/30s ISO400 FEC+1/3 I was able to sustain 2-4 shot bursts throughout the six hour session. I experienced less than 10 shots where the flash failed to fire with these settings.
I shot 2005 with 2100Mah nimhs. Comparatively very poor performance. Recycle time drops off quickly.
>>What are all you people shooting that makes these packs necessary? Or, is it just a matter of convenience to be able to use all 8 batteries at the same time?
I use mine in portable umbrella setups etc... very lightweight setup... when the flash is in manual mode and mainly 100%... eats AA batteries... getting 250+ full cap dumps is nice.
Yes, those batteries are dangerous because there is ALOT of power available... why you use them in the first place. Have to be careful. If I ever take the fake batteries out I will glue them to something that will act as a key so they can't be put in wrong.
I don't use a battery pack for my ETTL flash... just live with the AAs and lower recycle times. Wires etc. are more difficult to handle... there is something called an Underdog that is more commercial than my homebrew.
Cogitech, for me it is the occasional group event or wedding but primarily friday night football in the caves we call high school football fields. On average at least 500 shots of game action in very dark conditions. I can't rip high speed bursts but I can keep up with the play. One of the things I like about the black box is that it has 2 power outlets. So, I can power 2 different flashes with the same battery pack and save weight. I usually have 2 cameras going unless the play is very near the end zone when I drop to what ever short lens I am carrying.
During halftime I switch to the 5 with the tuxedo battery to shoot the bands. I don't even get close to making it sweat...
