Thursday, November 4, 2010

Portable flash and the art of NIMH batteries

This post is for my classmates, but pretty much anyone who uses a speedlight (or Canon speedlite) can get some information from it.  Read this post to learn why what batteries you use in your flash unit can really affect how it performs.


My Duracell 2650mah Nimh batteries charging on a Lacrosse Charger.  These guys
are over 2 years old and still pumping out consistent high capacity power.

In Wednesday class Photojournalism class, Ms. Finch gave use the lecture on portable flash units.  I was actually pretty impressed by her lecture, because she was 100% accurate about how easy it was for people to become scared of using portable flash power.  This post isn't about magic tricks on how to use the flash, resources on that are found all over the web at websites like this , this, or for the basics check this out here.  What this post is actually about is batteries, and how batteries can get you the most out of your flash.  Trust me, the read is worth it.

Trent Notes : I'm writing this through years of use and experience.  I've tried out numerous other battery solutions, and also been through oodles and oodles of weddings and events so my experience comes from hard usage of these batteries. 

One of the best things about speedlights is their portability, and a main factor in their portability is the use of small batteries to power up the flash.  Normally these batteries are the common double A's that we've been using since the dawn of battery time.  Double A batteries in the Alkaline form are pretty much ubiquitous, and can be purchased almost anywhere.  Obviously this makes the convenience factor of the double A standard to be pretty darn useful.  So here comes the kicker.  About 10 years ago NIMH batteries started becoming extremely affordable as a replacement for alkaline batteries.  The marketing pitch for NIMH batteries were they were more powerful (capacity and amp wise), they were reusable, and also had little memory effects in comparison to older rechargeable technology.  I highly suggest any techy science people read up on the above wiki link if they need help going to sleep.

So how does this affect you as a photographer using a speedlight?

Well I'll just throw you the hard details.  NIMH batteries should be the ONLY TYPES of batteries you use for your speedlight unit.  Here's the reasons why.

  • Affordability - NIMH batteries are really cheap in the long run.  You can a pack from Wal-mart, or Amazon ranging from $10 for 4, to $15 for 8 double A size batteries.  Yes this is more than the $2 you can spend for 4 really cheap off brand double A batteries, the benefit you get is re-useability of the NIMH batteries.

    A great place to buy NIMH batteries is Thomas Distributing

    I have had some batteries for years now that still hold a great charge, and have been worth the $10 I spent for them.  That's right, years.  When you can go through 20 double A's in one wedding, you can seriously eat through some crazy cash if you use Alkaline batteries.  Which leads us into the next reason.
  • Capacity -   NIMH batteries have an incredibly high amount of capacity.  Check out this info faq on NIMH batteries and others.  While I don't know if by electricity ratings NIMH's are higher in power than Alkalines, I do know by personal use that on 4 alkaline batteries my 580EX II flash will shoot about 125 1/2 power shots before it really dies down.  On NIMH batteries it's well north of 220 or more.  So that's what I mean by capacity.  When you are buying NIMH batteries look for a MAH rating.  MAH ratings pretty much are the "Gas tanks" of the battery.  The higher the number, the more energy it stores.  You can get 2900MAH batteries that hold a hefty charge that could last int he 400~500 of pops with your flash just on one charge.
  • Flash charging times - Here's something that's really useful for photographers.  Because of how NIMH technology is (which I don't know the exact reason why sorry), they charge flash units a lot faster than Alkaline units.  Where say a Alkaline flash unit at  full power will charge in 4~6 seconds, a NIMH one is ready in 2.5~3.5 seconds.  That's a world of difference when you are dealing with 1/32nd power and the NIMH flash is pretty much constantly ready while the alkaline flash has a noticeable delay.  You don't want to miss the shot.  This is a major advantage to photographers.
So these are three major reasons why to use NIMH batteries.  There's actually some other great reasons such as being environmentally friendly using Nimhs,  and also using precharged NIMH's but those factors are more universal where the above reasons really hit at home for photographers.  Something not covered in this post is using smart chargers for NIMH batteries.  While the units are more expensive than the cheap $6 units you can get that charge, smart chargers can increase the life span of your batteries by months or years.  Also something not covered is as mentioned the precharged NIMHS which on paper seem weaker with their standard 1800~2000mah ratings, but they do provide some advantages.  Please search google to find out more about those batteries.

I want to thank David Hobby at Strobist.com for his article on NIMH's.  I actually have never read it before, and while researching some links while writing this article stumbled upon it.  Mr. Hobby has been one of the most important people in the photography world the last few years, so I'm quick to make props to him.

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