Correction and update on the AGM sizing and battery disconnect options:
Rich says the AGM battery he's using to run 2-722's for 12+ hours is
rated at 33AH. That's higher than I suggested.
>I use a Werker AGM airtight non-spillable
>33 Amp Hour AGM battery.
>Batteries Plus ~$85.00
>Weight about 24 lbs.
>Model WKDC12-33J
Half the capacity for one 722 recorder would be ~17 AH-- in the
ballpark of the battery Aaron cited initially! Weight-wise, John's 2
X 14.4 volt sled approach comes out to about 9 lbs. at 5.7 oz/cell
compared to 24 pounds for the AGM. Here's the cell I'd use (many
vendors sell it):
http://www.batteryjunction.com/1dni10rebawi.html
Here's Nic's mention and link about the disconnect device he
suggests. If Rich's experience with a similar device applies., this
should get around the long duration switch-over issue.
At 2:06 PM -0500 5/14/09, Nic Stage wrote:
>Hello Rob,
>
>I am still in the process of inquiring with engineering to see if
>there were any changes to the power behavior of the powering
>functions in recent firmware. What version of firmware does your
>recorder have installed currently?
>
>Recently a user posted a detailed account of remote powering a
>7-series recorder using non-Li-Ion batteries. That thread can be
>seen here (You may need to register at our forums):
>
><http://forums.sounddevices.com/showthread.php?t=3D1802>http://forums.soun=
ddevices.com/showthread.php?t=3D1802
>
>In that thread, the user noted a low voltage disconnect device that
>could be placed between the battery and the load, which helped him
>avoid the issue of voltage bounce back when the recorder decided to
>switch over. This may be of use to you as well:
>
><http://www.lowvoltagebatterydisconnects.com/>http://www.lowvoltagebattery=
disconnects.com/
~ $140
e.g. http://www.psicompany.com/newmar-lvd-12-30-low-voltage-disconnect/
Rob D.
>
>Regards,
>
>Nic Stage
>Sound Devices, LLC
>800-505-0625 ext. 238
=3D =3D =3D
At 1:41 PM -0500 8/12/09, Rob Danielson wrote:
> At 9:35 AM -0700 8/12/09, Aaron Ximm wrote:
>> Hi,
>>
>>Can anyone give me the quick run down on what's needed to run a Sound
>>Devices 7 series recorder off a 12V (?) lead acid battery?
>>
>>I need to do some uninterrupted recording on the order of 24-28 hours,
>>two channel, probably 24/44, with a 722, providing phantom on both
>>channels. As are as I can tell I will need a pretty beefy battery --
>>anyone have field experience on what I really need? I was thinking a
>>26Ah battery would be conservative. Not to mention ridiculously heavy,
>>but I don't need to transport it into the back country, so that's OK.
>>
>>My specific questions are:
>>
>>Any guesses on the capacity I should really pursue?
>
>Hi Aaron--
>
>In warm weather, Rich's 23AH AGM battery will run two 722's for 10-12
>hours and pull the battery down to 50% (recommended minimum). If you
>can find an AGM in the 15-23 AH range, that should do it with some
>surplus which is good to have handy for cold weather.
>
>You _might_ get by with a 14.4 volt sled of the 10ah NiMh batteries
>that are available. I can get 12 hours from mine but I have to use my
>Maha charger, not just the "smart" chargers that run $30-50 they sell
>for sleds. On those, more like 8 hours.
>
>>
>>Is there a commercially available power cable adapter that terminates
>>in the appropriate connector for the 7 series recorders, and has
>>spades on the other end for batteries?
>
>Not that I am aware of and it not a super easy solder job, but
>doable. Look in your manual or on the SD site and solder one up
>according to their pin suggestions. Both Rich and I have our cables
>wired for operation and charging-- this works best for power
>switch-over issues.
>
>>
>>Do I need a lead acid battery charger? I have a lead on some very
>>affordable ones, but is this a must- or a nice-to- have?
>
>I use non sealed garden tractor batteries but the sealed ones are
>better and much safer. His 23AH is not too bad compared to what I'm
>accustom to. ;-)
>
>>
>>Any tips/pointers much appreciated. :D
>
>Rich has circuit that he made that disconnects the large, AGM battery
>after it reaches a designated low voltage. Then the 722's internal
>battery takes over through self power-down. If you don't want to mess
>with this, a larger external battery is pretty good insurance. SD
>also has info about a circuit they suggest in their forum or contact
>Nick Stage. I just use a larger battery, myself. BTW, my 744T did not
>have the switch-over problem until I got the hardware upgrade. I
>feared this might happen based on Dan's and John's reports. :-( Rob D.
>
>>
>>Thanks,
>>aaron
> >
>
>--
--
"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause
------------------------------------------------------------------------
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/naturerecordists/
<*> Your email settings:
Digest Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/naturerecordists/join
(Yahoo! ID required)
<*> To change settings via email:
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
------------------------------------------------------------------------
|