Hi Kevin,
I had this same challenge this fall, and researched two options:
(1) sealed lead acid battery: low cost, high weight
(2) drycell sled: higher cost, wasteful, much lighter and smaller,
more expensive.
Fwiw I can recommend impeccable Dan's work from personal experence,
and as a bonus when I asked, he had the parts on hand, if you go that
route. :)
I ended up however going with a Sonic Studios 12xD-Cell solution,
though it was considerably more expensive -- maybe 50-100% more than a
SLA solution. It's the BD-12T:
http://sonicstudios.com/batsys98.htm
It worked like a champ. The 14-hour recording I made with it (2x24/88
to internal HD, phantom to low consumption mics on both channels) went
off without a hitch. As per usual from Leonard, excellent build
quality. My only wish is that it came with a zipping case or
something.
It's *just* too big to wedge into the back of my 722's portabrace --
which has a deep relief to accomodate large capacity camcorder
batteries.
I made that call because I learned while deliberating that I was
selected to be an artist in residence Grand Canyon NP next year -- my
intention is to do some recordings in the side canyons there, and the
idea of lugging 25 pounds of SLA to get the same record time was
nonsensical!
I had been looking at 'emergency backup power' solutions like this and
the one branded Xantrex but apparently from the same supplier:
http://www.amazon.com/gp/product/B000TKHMWK
though I had also researched getting SLAs in the 25-35 amp hour range
made for motorized wheelchairs etc.: cheaper but without a built-in
charger, light, etc...:)
One gotcha I remain concerned about: that the 7 series doesn't
correctly switch from external battery to internal when the external
battery (on the Hirose connector) falls off.
My strategy was going to be to simply pull the plug when I reach 10%
expected life, switching to the internal -- that DOES apparently work,
without dropping any samples -- but I have to characterize true
battery life under load etc. Haven't done it yet. :P
aaron
--
quietamerican.org
oneminutevacation.org
83% happy
9% disgusted
6% fearful
2% angry
|