Tuesday, June 1, 2010

What's in the Bag? High Voltage Battery Pack


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This is the last post for this series, 16 in all. It has been a long and somewhat slow journey, so thanks to all of you who have hung in there reading each post and waiting for this thing to finally come in for a landing.

Do You Need One of These?

So what's the deal with a high voltage battery pack you may ask? Well, it makes the flash recycle really, really fast and adds a lot of reserve capacity. When you need a fast series of shots and are depending on flash for light, it is no longer a luxury, but a necessity. Can all flashes use a high voltage battery pack? No, but those that can will recycle faster and give a lot more flashes than with AA batteries. Some flashes, like the Vivitar 285HV, have a high voltage input that expects around 315 VDC. Quantum Turbo compatible high voltage battery packs have the electronics to make this high voltage from low voltage batteries. Paramount (and others) make a cable to fit between the flash and battery packs that have a Quantum Turbo compatible output jack. You can see mine hooked up in the photo above.

This is the JTL 2409 battery pack, that came with a JTL Mobilight 300 AC/DC studio light. It puts out about 315 VDC for powering the flash tube. It will recharge a 300 WS studio light from a full power dump in around 6 second, but lash it up to a Vivitar 285HV and you get sub 2 second full dump recycling, even faster with other flashes like the Canon 580 EX II. Of course, the studio light is about 4 (or more) times more powerful than most portable flashes, so for equal power settings recycling is on par for either light.

This particular pack uses Ni-MH batteries, so it is light and compact, yet inexpensive. Because of the self-discharge associated with Ni-MH battery chemistry, it is advisable to recharge the pack a day or two before use, but that is a minor issue considering how light it is compared to the SLA (Sealed Lead Acid) based alternatives. It also works with the Canon 580 EX II flash, Sunpak 383 Super, and probably some Nikon flashes too via the appropriate cable.

The JTL High Voltage Battery Pack sells discounted for around $135 making it among the least expensive battery packs available. Click Here to purchase the JTL 2409 battery pack from Amazon. There are other packs available too at various price points, and newer models come out from time to time. Each model has its own advantages and disadvantages, so a little research is advisable.

The cable is a Quantum Turbo compatible made by Paramount. It does the job and cost a lot less than the Quantum cable. So far it has proven reliable after many uses. I couldn't find it on Amazon, but here is a link to it on B&H (another great place for photo gear). http://www.bhphotovideo.com/bnh/controller/home?O=WishList.jsp&A=details&Q=&sku=40186&is=REG

Here are some more photos, not that you need them, but since I got a bit carried away photographing this thing I might as well make them available.


The naked battery pack. Notice the ventilation holes in the side. If the circuit overheats, then bad things can happen. To get around this one can either limit the number of pops or supply adequate ventilation (or both). Bear in mind that these packs are made for a 300 WS studio flash, so when lashed to a portable flash with around 50 WS, they are hardly working to recycle a full power dump. For the record, a WS is a Watt-Second and represents an amount of energy equal to that many Watts for one full second.

The flip side has ventilation too.

Even the bottom is ventilated.

All that ventilation gets duplicated in the case too.

That's all Folks
I swore I would never do another long series and then proceeded to hammer out the longest yet over these past few months. So much for promises. From now on, the only thing I promise is not to promise anything and just let the blog grow however it must. Anyway, last post, hope you found something useful in this drawn out series.

Coming Next
I'm thinking of posting a more technical article on color shift over min/max output range for my studio lights. Also thinking about a lighting setup using a gridded light to increase contrast. Another thought is to show a basic one light setup. In other words, I haven't yet figured out what to do next, so come on back to find out

Until then...

-Gene

6 comments:

  1. Interesting. i found this blog topic in one of those random link-of-a-link situations looking for external power options. the search was mostly for 580ex II options, but this lil thing may be just what i need to 1) resurrect my old 285HVs, and 2) postpone the pricey investment into monolights while keeping the relatively low profile of speedlights on stands. very cool. i can't find any proper reviews of this thing, so if you have a moment enough for a few questions: charge time? average shot count per charge with the 285HV? and can it power a flash while charging or plugged in? Thanks in advance, but if you can't reply then no worries. Thanks enough for the point of reference.

    bookmarking for reference.
    - noel.

    ReplyDelete
  2. For Noel (Anonymous)...

    Charge time is under 4-hours. You cannot use it while it is being charged. I estimate that you would get around 720 full power flashes with one of these. That is based on getting about 120 flashes with a 300 WS studio light. Since the 285HV is about 50 WS, the math goes 120 x 300/50 = 720.

    Since writing this article I have begun using the new Ni-Zn (Nickel-Zinc) batteries, which put out a higher voltage than Ni-MH or Alkaline cells. These cells get the recycle time down to under 4-seconds for a 285HV, so I almost never use the power packs anymore.

    ReplyDelete
  3. Gene Lee,
    Thanks so much for the reply. I'm looking mostly for wedding reception options to boost ambient light. with the external battery I assume that I would be able to set it on a stand and forget it. While using internal batteries I'd have to change them out at least once during a dark reception. What has your experience been with shot count on the Ni-Zn? I've heard they run very hot too.

    I'm currently using the Sanyo Eneloops 2700mAh NiMH based on reviews from a little over a year ago. They don't last as long as I would expect, but then again my experience is limited. Probably just user error =) I'm still researching, but ideally I'd love to have 2x Vivitar 285HV with some type of external power on stands near the dance floor, bounching or direct to boost ambient. I'll have my 580ex II on camera for fill. In regards to the JTL 2409 vs Ni-Zn, I don't know if one charge either way would carry me through a reception, but that's the idea. I may just have to suck it up and get alienbees as at the moment, my biggest gripe is chasing batteries. But i'm still new. Lots to learn...

    Anyway, sorry for the ramble!! And thank you again for your reply.

    - Noel

    ReplyDelete
  4. For Noel (Anonymous)...

    What you describe is very much what David Ziser sets up except that he is using Quantum flashes. He also has an assistant with a light on a pole for his off-camera flash.

    From what you describe, while Ni-Zn would give faster recycling, it might not be fast enough for capturing a wedding reception with high activity. You might also end up needing a battery swap in the middle of the reception. I would hope that 720 full power pops would be enough, but if not, you might want to check out the Quantum Turbo 2+2 power pack, which MAY have more capacity.

    Best to you and thanks for reading and commenting.

    Gene

    ReplyDelete
  5. No need to post this reply, but I did want to take a moment to thank you for the Ni-Zn reference. I used them last weekend during a reception---1 on camera flash and one off on a stand near the DJ gear. Worked GREAT! They really put my Sanyo's to shame as for recycle time.

    Thank you again,
    - Noel

    ReplyDelete
  6. Hi Alfonso,

    The flash must have batteries installed to run the low voltage circuits. The 285 does not utilize the low voltage power that is available from the battery pack.

    I believe that the 285's high voltage circuit works in tandem with the external HV battery pack, so it would seem prudent to use the best cells available. Some experimentation might be in order to determine which setup is right for you.

    I used to put Ni-MH in the flash and have alkaline cells for backup. I am not doing weddings these days, so now use Ni-Zn cells for primary and backup.

    One word of caution for Ni-Zn cells. Be careful not to discharge them completely. Reports are circulating that they do not tolerate being fully discharged. It appears to damage the cells. I'm comfortable with that limitation, as my use is not all that demanding. When using an external battery pack, I suspect that Ni-Zn cells would last all night. However, I've not done any experimentation to prove this out.

    ReplyDelete

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