Hi Debbi,
I previously mentioned similar frustrations with NiMH 8.4v/150mAh
batteries in my PB224 that died halfway through a dawn chorus. My
solution was building a battery sled for twelve AA NiMH batteries. The
PB224 specs call for 12 to 18 volts for external power, so 14.4 volts
seemed a happy medium. I used three four cell Radio Shack battery
holders, glued them to a thin piece of wood, soldered them together,
and added a wire and the same DC connector Rob used in his examples.
The whole thing fits conveniently into a pencil case.
Here's the photo I previously posted:
http://www.rockscallop.org/how/batpack01.jpg
In the picture, you notice a mixture of brands and capacities, however
this is not recommended. Since then, I bought matching batteries and
also added three broccoli rubber bands to secure the batteries better.
Rob had mentioned Batteryspace.com, so I gave them a try and ordered a
twelve pack of Powerizer 2500mAh AAs at a very fair price.
http://www.batteryspace.com/index.asp?PageAction=3DVIEWPROD&ProdID=3D2554
I also bought their 8 cell CH-V6280 Smart Bay Charger
http://www.batteryspace.com/index.asp?PageAction=3DVIEWPROD&ProdID=3D2606
With this system you have to remove the batteries to charge them, but
the nice thing is they charge quickly. After 8 hours of recording the
batteries still had enough juice left that each needed only about
1hour to charge to full =96 so two hours total with the 8 cell charger
and your ready for another night of recording.
If you want to stick with the internal 9V batteries, Walt suggested
this: "The Maha MH-C490F charger can charge the newer 8.4V & 9.6V Nimh
batteries in two hours. 1-4 of them at a time. Works off 110V, car
battery or I've tested it with a solar panel. There is also a 10
battery version but it's 110V only.
http://thomas-distributing.com/maha-powerex-mh-c490f-9v-battery-charger.htm
You do need the newer batteries designed for fast charge. I use
Powerex 9.6 volt, but there are other brands. Probably other fast
chargers too."
-John Hartog
--- In Rob Danielson <> wrote:
>
> Hi Debbi--
> Sorry about the missed mock. I can reliably record a 93 minute 1GB
> disk on two "9 volt" NiMH batteries rated at 160 mAh powering to
> NT1-A's. Duracell MN-1604 Alkaline 9 volt batteries are rated at 550
> mAh, so you should be able to get over 4 hours of continuous
> operation out of these. The NiMH are 8.4 volts not 9 volts though,
> which lowers their performance.
>
> I just hate throwing away batteries after one use.
>
> Here are some rechargeable LiON 9 batteries rated at 400mAH
> http://www.batteryspace.com/index.asp?PageAction=3DVIEWPROD&ProdID=3D2644
> and the Charger for charging one at a time:
> http://www.batteryspace.com/index.asp?PageAction=3DVIEWPROD&ProdID=3D2643
>
>
> For the 7+ hour recordings I most often make, I'm using the 12 volt
> external power input (uses Radio Shack Type M plug) and a battery
> "sled" that can run the Rolls for days.
> http://www.uwm.edu/~type/audio-reports/HiMD/HiMDbattery-sleds.htm
> (thats my over-kill battery sled)
> Note the polarity on the Rolls and Art connector is non-standard,
> negative center.
>
> For you, a sled of 10 X 1.2 volt AA size 2500mAH NiMH batteries
> should provide plenty of power for a day's recording, even if left on
> all the time.
>
> Here are some sample deals on AA NiMH bats, holders and chargers:
> 12-AA:
> http://www.batteryspace.com/index.asp?PageAction=3DVIEWPROD&ProdID=3D2554
>
> 24-AA's for two, complete 12volt packs:
> http://www.batteryspace.com/index.asp?PageAction=3DVIEWPROD&ProdID=3D2120
>
> You'd need AA battery 2-sleds to hold the 10 cells:
> 1- http://www.batteryspace.com/index.asp?PageAction=3DVIEWPROD&ProdID=3D2=
122
> 1- http://www.batteryspace.com/index.asp?PageAction=3DVIEWPROD&ProdID=3D2=
120
> (doube for two sled)
>
> I'd get a charger designed to charge the whole 12 volt sled at once
> so you don't have to dismantle the sleds to charge them.
> http://www.batteryspace.com/index.asp?PageAction=3DVIEWPROD&ProdID=3D2051
>
> Its burned into my head: "No such thing as too much power or tape."
> But I still run out, often.
> Please report back on your solution!
> Rob D.
>
> =3D =3D =3D =3D =3D
>
>
>
> At 11:45 AM -0700 7/1/06, Debbi B wrote:
> >It seems like the 9v batteries in my power supply (used with Rode
> >NT-1A) don't last very long. I used it to record maybe half an hour
> >worth of actual recording, not including on pause, which was probably
> >30-60 minutes if that. Previous to this either I've forgotten to turn
> >off the power supply or the switch got turned on in my bag. This time
> >I made sure to turn it off.
> >
> >Is this within the normal range one would expect batteries to last?
> >
> >(Of course, just when I want to use it, I don't have any extra
> >batteries. The neighborhood Mockingbird has been including "meow"s in
> >its repertoire.)
> >
> >Debbi
> >
> >
>
>
> --
> Rob Danielson
> Peck School of the Arts
> University of Wisconsin-Milwaukee
> http://www.uwm.edu/~type/audio-art-tech-gallery/
>
>
>
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