Recording long duration without power

Discussion in 'Location Recording' started by tycato, Dec 13, 2011.

  1. tycato

    tycato Member

    Unsure of where to post and this seemed most accurate. I am doing a project about blindness and reliance on other senses. I am going to follow my cousins on a hunting trip and want to record the audio the entire time. Later I will edit this audio down. The problems are lack or power source for most of it. What should I buy that can record a week of audio without needing more power? Would it be easier to get a camera and just isolate the audio track afterward? Ideally I would have one recording at the camp going 24/7 and another to carry with me on outings, this means it can be a day or two between being able to change batteries at the camp. It's not super important to be able to do it without changing batteries all the time but thought maybe you guy could give advice.
  2. JoeH

    JoeH Well-Known Member

    I think you're going to be out in front on this one, Ty, although I'm sure things like this have been done before.

    The newest portable 2-track recorders come to mind, but you'd do well to check on what they offer in terms of recording time/battery life. (I know the now-older M-Audio Micro Track II's have built-in batteries, so you can't swap them out with recharged backups.)

    Maybe get something that runs on AA batteries (or roll your own adapter from batteries & clips?) and just bring a box of them along? Once you do get to civilization & AC power, you could recharge your stuff.

    The less moving parts the better, of course, so today's new portable recorders with SD chips are great for this sort of thing. Make sure any onboad display lighting is disabled (or turns off after a certain amount of time).

    If you're looking to record continuously without any breaks, you should probably have two of everything, so when you swap things out (like memory cards, batteries, etc.) you're always still rolling/recording.

    I'm sure there are others with even more portable power-supply ideas out there.......
  3. TheJackAttack

    TheJackAttack Distinguished Member

    Also worth mentioning are portable solar chargers. Combine one if those with a lithium charger or even sla charger and you would have your base camp power.
  4. Boswell

    Boswell Moderator Distinguished Member

    Your two major problems are battery capacity and data storage capacity.

    The battery capacity can fairly easily be got round by selecting a recorder that has a d.c. inlet jack (rated at, say, 6V) and then using an external small 6V caravan-style battery. It would need a back-of-the-envelope calculation to get a minimum Ah rating, but I would guess you would get a week's running out of a 6Ah battery. Something like the Sonnenschein A506/6.5S might be suitable. A simple linear regulator could be used between the battery and the recorder if the d.c. inlet jack has a maximum rating of less than 6V. Selective use of a solar charger, as Jack suggested, may well allow you to choose a battery with a lower Ah rating and hence lower weight.

    Data storage capacity is more of a problem if you have only a single recorder. For use on long-ish outdoor recordings, I often use an iRiver H140 portable recorder that came with a 40GB hard drive, but there are hacks around that can replace that with a more modern 240GB drive. The difficulty with these portable hard disk recorders is that you cannot write continuously to the whole drive, and the problem is not limited to the iRiver products. With the H100 series, the recording stops after around 2GB of writing, and you have to start a new file. It will store stereo tracks as .wav files or various different bitrate .MP3 files, so you can get a fair length of time per file if you don't mind MP3 quality.
  5. TheJackAttack

    TheJackAttack Distinguished Member

    Some recorders simply break the audio into 4mb chunks which are seamless when placed adjacent in a daw. My PMD671 does this and I think Sound Devices and Fostex do the same in bwf.

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