I have a week-long recording trip coming up soon, so I've conducted a
few battery life tests of my own. My setup: FR-2LE recording at
24/44.1; a pair of AT3031 cardioid condenser mics with preamp at full
gain; headphone amp feeding a pair of Sony MDR-7506s at a comfortable
listening level. Like oryoki, I got it going indoors and went about my
business. Here's what I found:
* Approximately 3.5 hours recording time with four AA alkaline
batteries in the supplied battery sled.
* Approximately 5.5 hours recording time with a 6V zinc-carbon lantern
battery (connected the best way I could to the Tamiya battery sled
* Approximately 9 hours recording time with a 7.2V 4200mAh NiMH Battery
Pack from batteryjunction.com:
* Approximately 14 hours recording time with the 7.2V 4200mAh NiMH
Battery Pack and an external mic preamp feeding the FR-2LE line inputs.
Every time max file size, max CF card capacity or low battery
conditions were reached, the FR-2LE politely closed the file it was
recording and either shut down (in the case of low power) or displayed
its max default capacity message. Nice box. Ugly as can be, but darn
> The Fostex FR-2LE has the ability to carry a 7.2V RC Car battery
> internally, in place of the standard battery sled that holds four AA
> cells. Fostex says a 3600 mAh battery of this type should provide 8
> hours of WAV recordings.
> I received a 3800 mAh 7.2V RC car battery and charger from an eBay
> retailer last week. The RC battery weighs more (340 g vs 160 g for
> the standard AA battery sled), but it fits easily into the battery
> To test the RC battery life, I set up the FR-2LE to record in 192Kbps
> MP3 to a 4 GB Compactflash card. I started recording the household
> ambience, and went about my business. 12 hours later, I was surprised
> to find the recorder still actively recording. I saved the file and
> continued recording. At the 17 hour mark I gave up and ceased
> I shut down the recorder and transferred the Compactflash card to a
> PC. At first I could see no files on the card, so I ran CHKDSK /F.
> The program recovered two files. I renamed them to have the MP3
> extension. At this point, Windows Media Player recognized the files
> and had no trouble opening and playing them.
> In my experiment, the FR-2LE ran for 17 hours and created 1.4GB of MP3
> files. The battery still shows 3/4 full! Running from AA cells, I
> don't get more than 4 hours.
> Certainly it takes less energy to create a low bit rate file like
> 192Kbps MP3 than it does to record at 24/96 WAV. So I have more
> testing to do.
> At this point, though, I feel confident that that the 3800 mAh RC car
> battery will easily power the FR-2LE for an all-day session in the
> field. Thanks, Fostex, for adding this feature to the FR-2LE!