At 10:14 PM -0700 9/5/05, Lou Judson wrote:
>All this battery info is great, against future need for me. But a=A0
>question:
>
>Why use 10 cells for 15 volts when the SD units spec 10 - 18? in the=A0
>external supply?
Good questions. The nimh cells are effectively
1.2 volts each after a few minutes of discharge.
The charger is working at about 15.6-16.2 volts
iniitally to charge this pack so anything larger
really taxes it. Also, its useful to be able to
charge packs with a car's battery (or plane's
Greg?). The 722 does shut-down just under 10
volts, so, yes, that's an argument for starting
closer to 18 volts, like maybe 14 of the smaller
"C size" which still pack a whallop. You'd need a
pretty special charger for this size of pack and
I'm cautious about "winging" the NiMH charger
side, DIY. (The RC folks may know of something
that charges at about 20-22 volts). Some
recorders can take a larger voltage drop than
this, it could be that the ECO 12 volts are made
more for recorders that don't need the sustained
higher voltage like the 722. Maybe some one has
some experience about this they can share.
I can't tell for sure, but it looks like
Leonard's pack (sled+ HiRose) is made for
rechargeables or non rechargeable batteries. One
can buy the parts to solder up two of these for
~$50. Of course one can use rechargeable NiMH's
in this 12 bat sled but I can't think of a way to
re-charge them except to pull them out and put
them into 3 seprarte tray chargers. I did this
for a while and realized I really needed
"packs." Rob D.
=3D =3D =3D
>Is it for longer life as the original voltage is=A0
>higher? Wouldn't it work as well using the 8 pack at 12V which would be=A0
>a more compact package? Curious if you have tried that and found it=A0
>lacking... I would think seriously about using 8 cells, building two=A0
>packs, and leaving one to charge before switching. Unless you'll be in=A0
>the outback for weeks!
>
>I used to run my D-100 DAT, and before that a D-6 casette, from 4 D=A0
>cells similarly ... so been there assembling such things!
>
>Thanks,
>
>Lou
>On Sep 5, 2005, at 9:52 PM, Rob Danielson wrote:
>
>>
>> The 722 does use some juice but these packs have considerable
>> capacity, about as large as one can go. (Though the RC hobby folks
>> always have new, hi capactity, low weight/bulk, batteries they are
>> trying out it seems). A charged pack will hold a charge for easily a
>> couple of weeks. Here's a page with more info:
>> http://www.uwm.edu/~type/Mic%20Preamps/BatteryPack_NiMH_722/
>> Battery10KaHr_722_744.htm
>> Rob D.
>>
>> =3D =3D =3D =3D
>
>
>
>
>"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
________________________________________________________________________
________________________________________________________________________
"Microphones are not ears,
Loudspeakers are not birds,
A listening room is not nature."
Klas Strandberg
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