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Re: extended recording expedition advice

Subject: Re: extended recording expedition advice
From: Rob Danielson <>
Date: Wed, 2 Nov 2005 08:07:25 -0600
I'm cheapie at heart. Maybe to a fault! "240 Cranking Amps" is what
they say on top. They're about 9"X 6" X7", come with carrying handle,
cost $30 each and you are absolutely right, they can be spilled!
Many times I've toted one for miles inside of a backpack wrapped
inside of an 1/8" thick rubber sheet. Never spilled a drop so far but
I wouldn't hike on loose gravel either.  Gell cells would be
fantastic and much safer. How many cells/packs would one need to pull
down 3 amps at 12vdc for say 24 hours? How about bulk and weight?
Cost? Too often I prove that my motto, "You never have enough power
and disk space." is correct.  I can stop at an AC outlet to put a 50
amp quick charge on a garden tractor battery and be 95% sure I'm
heading out with enough power to get me through two days if needed
(no powering external hard drive though).   Rob D.

At 8:39 AM +0000 11/2/05, werainey wrote:
>Rob,
>
>Is  the  240AHr a typo? That would be a big  lead acid battery. After
>inconvenient accidents with tipping and  draining of wet cell garden tract=
or
>batteries, I'd suggest the more expensive option of ganging equivalent
>capacity of smaller gel cell or AGM batteries. No orientation
>issues, easier to
>carry, more tolerance for deep discharge if the right models are
>chosen/available..
>Bill R.
>>  One thot here: Be prepared with more than one "solution" to the power
>>  challenges. For your fixed site recordings, I'd consider one or two
>>  "small" ~240AH 12 volt garden tractor size lead acid batteries.
>>  They'll run a 722 for days, but best of all, they can be fast-charged
>>  with car battery chargers you're likely to find even in remote places
>>  or with a small 1-2 amp trickle charger you can carry with you. The
>>  Sound Devices site has considerable discussion about power options
>>  too. For portability with long duration ability too, I recently added
>>  two more cells to one of my D-Cell NiMH packs and the MAHA charger
>>  seems happy charging it (while on AC!). The 722/744 runs much longer
>>  on 12 cells (than 10) because of the large voltage drop to 10.8
>>  volts, the cut-off point.
>>
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>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
>


--
Rob Danielson
Film Department
University of Wisconsin-Milwaukee


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