Seeking Advise on Portable Power...

Discussion in 'Location Recording' started by vttom, Apr 12, 2011.

  1. vttom

    vttom Active Member

    I have a friend who's getting married this summer. It's an outdoor service in a park far away from any electrical service. However, they do expect ~100 people and would like sound amplification for people speaking, and for the musical components of the service and I offered to do the sound.

    So... I started looking into battery-supplied portable power units (a gas-generator would be a total no-go as it would be too smelly and noisy). I think something along the lines of the following would do the trick: Schumacher PP-2200 Portable Outdoor Power Unit: Automotive Duracell DPP-600HD Powerpack 600 Jump Starter & Emergency Power Source with Radio: Automotive

    But before I commit to one of these, does anyone have any advice to offer? Am I on the right track or barking up the wrong tree?

    Note that the only load will be either my Yamaha StagePas300 (includes 8in speaker cabs) or EMX312 powered mixer (into a pair of 8Ohm, 12in cabs), which peak out at 300 and 600 Watts respectively (although we won't be pushing them anywhere near that hard). Inputs will be 4(+/-) dynamic mics and maybe DI'd e-acoustic guitar and maybe DI'd electric bass.

    I'm thinking 1hr of up-time should be more than enough. A quick back-of-the-envelope calculation makes me think I'd need at most 1-2Ah @ 120V, which roughly translates to 10-20Ah @ 12V. (both units above advertise >20Ah batteries, so I think I'm good).
  2. TheJackAttack

    TheJackAttack Distinguished Member

    The newer generations of small generators aren't that loud and if situated correctly noise and odor won't be an issue. You need to look at the published draw specs of the battery packs. For instance I have a Furman SB1000 UPS that is rated at 5A/600W draw for all of three minutes. I have a Cyberpower CPS1500AVR that is rated at 950W for six minutes full load. Granted you would be under full load but I use it to illustrate. The fact that the batteries are 20AH are not indicative of useful time necessarily.
  3. vttom

    vttom Active Member

    If you follow the link for the Schumacher you'll find the following chart.

    It says it can drive a ~160W load for ~50 minutes. Elsewhere it says it can source 400W continuous and 800W peak. Seems to me it's got the capacity I need.

    But specs are one thing and real-world usage is another. I was hoping someone on this forum has used something like this for a ~1hr program. If noone has, then maybe that, in itself, tells me something. :)
  4. TheJackAttack

    TheJackAttack Distinguished Member

    I have used UPS units to power tube mic PSU's for a main stereo pair. That doesn't put the UPS under much load however. Your specs would seem to indicate it can handle what you're asking. I'd test drive it before I hauled it out there. Battery technology has improved in the past several years.
  5. Boswell

    Boswell Moderator Distinguished Member

    This is very much a job for a small generator and not a UPS. At a wedding, you simply cannot afford the UPS to run out as soon as it hears the celebrant's vocals starting up, and, believe me, they can be pretty selective. As a last resort for this sort of occasion, I have in the past used a 12V inverter plugged into a car cigar lighter socket and then started the car engine when the crucial part of the procedings arrived.

    I have both the Yamaha Stagepas 300 and 500 units in my hire stock, and usually discourage potential hirers from using the 300 for outdoor events, as it does not have the reserve of power for open-air work. In addition, 300s have a history of activating their cutout if pushed hard.

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