{"items": [{"author": "Andrew", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103597516582", "anchor": "fb-10100103597516582", "service": "fb", "text": "Do you expect losses from the inverter? I don't know how high to expect them to be, but I'd think they'd be non-negligible.", "timestamp": "1564107343"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103597516582&reply_comment_id=10100103598439732", "anchor": "fb-10100103597516582_10100103598439732", "service": "fb", "text": "→ I'm measuring on the battery side of the inverter, so I think any inversion losses are already factored in?", "timestamp": "1564107611"}, {"author": "Andrew", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103597865882", "anchor": "fb-10100103597865882", "service": "fb", "text": "Also, can you just run the bulk of the equipment (say, the laptop driving the speakers through the mixer) at reasonable volume for an hour and see how much it drains the battery?", "timestamp": "1564107408"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103597865882&reply_comment_id=10100103598634342", "anchor": "fb-10100103597865882_10100103598634342", "service": "fb", "text": "→ The main problem is that a realistic volume is really very loud. Sound sufficient to fill a good chunk of Copley Plaza isn't something I want to subject my housemates or neighbors to.", "timestamp": "1564107671"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103598534542", "anchor": "fb-10100103598534542", "service": "fb", "text": "Check in with Edward, he's done this many times!", "timestamp": "1564107651"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103598534542&reply_comment_id=10100103598654302", "anchor": "fb-10100103598534542_10100103598654302", "service": "fb", "text": "→ Hi Ed!", "timestamp": "1564107684"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103598534542&reply_comment_id=10100103599058492", "anchor": "fb-10100103598534542_10100103599058492", "service": "fb", "text": "→ My own limited experience doing outdoor sound is that you need at least four times as much power as for a similar indoor dance. However, Copley is also a large area with the dancers spread out further than normal, though as I haven't been for a few years, that might have changed. I would prefer to do it with four mains.", "timestamp": "1564107892"}, {"author": "Danner", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103598534542&reply_comment_id=10100103629796892", "anchor": "fb-10100103598534542_10100103629796892", "service": "fb", "text": "→ When I asked Ed, he said \"just rent a Honda e2000 generator from home depot\" so that's what I did. I'd definitely bring something as backup for the first run off your battery.", "timestamp": "1564141603"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103598534542&reply_comment_id=10100103666173992", "anchor": "fb-10100103598534542_10100103666173992", "service": "fb", "text": "→ Honda's generators are VERY quiet.", "timestamp": "1564162189"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103598534542&reply_comment_id=10100103666228882", "anchor": "fb-10100103598534542_10100103666228882", "service": "fb", "text": "→ But even with a louder generator, careful positioning makes it possible to ignore.", "timestamp": "1564162231"}, {"author": "Kiran", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103601812972", "anchor": "fb-10100103601812972", "service": "fb", "text": "Grr, does this mean I'm missing the Copley outdoor contra? \ud83d\ude15", "timestamp": "1564109545"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103602511572", "anchor": "fb-10100103602511572", "service": "fb", "text": "I've seen warnings that the power that comes out of an inverter off a battery, is not a very good sine wave shape, maybe more like a square wave. Unclear whether your sound equipment may not behave well on such power. I can imagine some power supplies, using electronic switching to convert AC to lower voltage DC, might be designed to work with a sine wave, and might not work well with the inverter output.", "timestamp": "1564109953"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103602511572&reply_comment_id=10100103629073342", "anchor": "fb-10100103602511572_10100103629073342", "service": "fb", "text": "→ Michael the inverter I have is a pure sine one, so I think I'm ok there.", "timestamp": "1564140711"}, {"author": "Danner", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103603175242", "anchor": "fb-10100103603175242", "service": "fb", "text": "want to bring my 2 battery powered speakers as backup? They have moped batteries and last 8 hours or so. mic, instrument, and aux in? probably not enough, ehh?", "timestamp": "1564110707"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103603175242&reply_comment_id=10100103629103282", "anchor": "fb-10100103603175242_10100103629103282", "service": "fb", "text": "→ Danner model name or spec link?
Mostly I want to look up their output level; my guess is they're not enough to make a difference.", "timestamp": "1564140787"}, {"author": "Danner", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103603175242&reply_comment_id=10100103629392702", "anchor": "fb-10100103603175242_10100103629392702", "service": "fb", "text": "→ American audio els go 8bt. 110dB Max SPL. No they aren't the biggest, but they're also definitely PA speakers, and they definitely can go painfully loud.", "timestamp": "1564141229"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103603175242&reply_comment_id=10100103629876732", "anchor": "fb-10100103603175242_10100103629876732", "service": "fb", "text": "→ Those look like they'd work well as monitors: that would cut ~135Wh off the requirements, which is pretty good! If you could bring them that would be great!
(I'd still bring my own monitors in case something happens)", "timestamp": "1564141658"}, {"author": "Danner", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103603175242&reply_comment_id=10100103630625232", "anchor": "fb-10100103603175242_10100103630625232", "service": "fb", "text": "→ Yeah, and the slower the battery drains, the more of those watthours are useful.", "timestamp": "1564142242"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103629193102", "anchor": "fb-10100103629193102", "service": "fb", "text": "Two of my things (keyboard, footboard) run off 12v DC so I was thinking about whether it made sense to connect them directly to the battery. And avoid the double conversion losses. But they just don't draw that much.", "timestamp": "1564140907"}, {"author": "Danner", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103629193102&reply_comment_id=10100103629657172", "anchor": "fb-10100103629193102_10100103629657172", "service": "fb", "text": "→ Do they change anything as the voltage changes? They're gonna move from 14v to 11.5 as the battery discharges.", "timestamp": "1564141458"}, {"author": "Edward", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103629193102&reply_comment_id=10100103631688102", "anchor": "fb-10100103629193102_10100103631688102", "service": "fb", "text": "→ Jeff Kaufman do not do this.. most 12v as Danner said wont regulate properly off the battery. I've seen equipment blow up at 13.5v", "timestamp": "1564142996"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103629452582", "anchor": "fb-10100103629452582", "service": "fb", "text": "Kem I hear a rumour you have experience with running dances off batteries?", "timestamp": "1564141266"}, {"author": "Edward", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103630710062", "anchor": "fb-10100103630710062", "service": "fb", "text": "So yes I've done this.. here is the issue... sound power requirements go up exponentially with volume and also with the amount of \"bottom\" end or bass you require. I've done this with battery, but I also ran subwoofers. The system used just over 4kwh as I was also running lights. You do need a couple of lights.
The easiest way is to use a generator which i have done for the past couple, then there is no issue.
Inverters are about 80 to 90%efficient.", "timestamp": "1564142335"}, {"author": "Edward", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103631348782", "anchor": "fb-10100103631348782", "service": "fb", "text": "So. Battery systems are complicated. Most use internal sound compression and very conservative low end management to keep the power requirements low. My Experiance is when you turn the volume up on any battery systems, they fall flat as the circuitry tries to conserve power. The k10s will work fine, but they will require a bit more power. My favorite off the shelf battery systems are the goal zero yeti lithium. Bigger the better.", "timestamp": "1564142673"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103631353772", "anchor": "fb-10100103631353772", "service": "fb", "text": "I wonder if I should just get another 100ah battery.", "timestamp": "1564142674"}, {"author": "Edward", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103631523432", "anchor": "fb-10100103631523432", "service": "fb", "text": "And you will need lights.
I think that 2 100ah batteries will be fine as long as you conserve your low end. Run a couple battery powered shop lights when it gets dark.
Another thing to consider....
When it does get dark, you want to keep an eye on your stuff there. There are always some shady people lurking around.. hence lighting.", "timestamp": "1564142852"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103631523432&reply_comment_id=10100103631593292", "anchor": "fb-10100103631523432_10100103631593292", "service": "fb", "text": "→ Edward thanks!
Lights are pretty cheap even though an inverter, now that we're on to LEDs.", "timestamp": "1564142962"}, {"author": "Edward", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103631523432&reply_comment_id=10100103632681112", "anchor": "fb-10100103631523432_10100103632681112", "service": "fb", "text": "→ No problem!", "timestamp": "1564143600"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103662316722", "anchor": "fb-10100103662316722", "service": "fb", "text": "Peter has a generator that has been used at Copley before. I'm sure you're trying to avoid direct use of fossil fuel, but point this out as a possible option.", "timestamp": "1564160218"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103662316722&reply_comment_id=10100103665275792", "anchor": "fb-10100103662316722_10100103665275792", "service": "fb", "text": "→ Michael avoiding fossil fuel isn't my goal, though a generator being loud could be a problem?", "timestamp": "1564161792"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103662316722&reply_comment_id=10100103665699942", "anchor": "fb-10100103662316722_10100103665699942", "service": "fb", "text": "→ Jeff Kaufman He's used it for Copley dances before.", "timestamp": "1564162074"}, {"author": "Danner", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103662316722&reply_comment_id=10100103671383552", "anchor": "fb-10100103662316722_10100103671383552", "service": "fb", "text": "→ The generator is run 50 feet away, and is about 50dB. You won't have any problem with the volume based on the generator.", "timestamp": "1564164689"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103662316722&reply_comment_id=10100103689177892", "anchor": "fb-10100103662316722_10100103689177892", "service": "fb", "text": "→ Danner Honda small quiet generators and their knockoffs are totally different from less expensive, unenclosed generators like the one Peter has. While one can deal with the noise, there is noise and one has to plan around it.", "timestamp": "1564171288"}, {"author": "Danner", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103662316722&reply_comment_id=10100103689242762", "anchor": "fb-10100103662316722_10100103689242762", "service": "fb", "text": "→ oh, yeah, I don't know what peter has. I've just rented home depot honda e2000 for $60 for a day.", "timestamp": "1564171365"}, {"author": "Michael", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103662316722&reply_comment_id=10100103713249652", "anchor": "fb-10100103662316722_10100103713249652", "service": "fb", "text": "→ Danner I didn\u2019t know HD had them! Something to keep in mind!", "timestamp": "1564181571"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103675165972", "anchor": "fb-10100103675165972", "service": "fb", "text": "There's a FB event for the dance now: https://www.facebook.com/events/428788117721073/", "timestamp": "1564166235"}, {"author": "Peter", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103686558142", "anchor": "fb-10100103686558142", "service": "fb", "text": "You may use my generator, but it\u2019s both loud and heavy. I can just barely lift it myself and I\u2019m a pretty burly guy. Also, I\u2019d get a long extension and run it far away behind some stuff. It puts out 3000w and you\u2019d probably not use more than a tank of gas. I\u2019d recommend running at least 100w of incandescent lighting to stabilize the load and control power factor.", "timestamp": "1564170213"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103686558142&reply_comment_id=10100103700036132", "anchor": "fb-10100103686558142_10100103700036132", "service": "fb", "text": "→ Peter thanks! Phillip is giving me and my gear a ride, so we could pick it up before the dance and drop it off after?
I think I'd plan to use it as a backup, if after measuring power usage at sound check (or the break) it looks like we don't have enough battery.
Do you think a 100W fan would work similarly for controlling power factor? I don't think I have any incandescent lighting!", "timestamp": "1564175808"}, {"author": "Peter", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103686558142&reply_comment_id=10100103712231692", "anchor": "fb-10100103686558142_10100103712231692", "service": "fb", "text": "→ I don\u2019t think a motor is as good for this purpose as the simple resistance of an incandescent lamp. I probably have a bulb kicking around somewhere.", "timestamp": "1564180964"}, {"author": "Nathan", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103686827602", "anchor": "fb-10100103686827602", "service": "fb", "text": "I wonder about using an electric car (battery) for this type of thing. For example my Bolt has a 60 kWh battery which would provide plenty of power. Would need to buy an appropriate inverter though (380 vdc to 120 ac). They exist but start at ~$1000 for a 30 kw model so probably not the cheapest approach. Sorry I am out of town right now and will not be able to help.", "timestamp": "1564170288"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103686827602&reply_comment_id=10100103686947362", "anchor": "fb-10100103686827602_10100103686947362", "service": "fb", "text": "→ Nathan how much power will it let you draw from the 12V port?", "timestamp": "1564170424"}, {"author": "Nathan", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103686827602&reply_comment_id=10100103694197832", "anchor": "fb-10100103686827602_10100103694197832", "service": "fb", "text": "→ Jeff Kaufman not sure. I\u2019ll have to look that up at some point. The 12 volt outlet is only good for 5 or 10 amps. However probably a bit more could be pulled directly off of the 12 v battery. There is a charger (from the main battery) for the 12 volt battery which is sized to keep up with the normal loads, lights, windshield wipers etc. maybe up to 30 amps or so? Not sure exactly what it would keep up with. However It would be more efficient to invert off the 380v dc from the fast charger connection than to go to 12 volt and then back to 120ac I think.", "timestamp": "1564174187"}, {"author": "Edward", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103686827602&reply_comment_id=10100103760954052", "anchor": "fb-10100103686827602_10100103760954052", "service": "fb", "text": "→ Carefull with lithium diy!!!!", "timestamp": "1564225214"}, {"author": "Edward", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103686827602&reply_comment_id=10100103761028902", "anchor": "fb-10100103686827602_10100103761028902", "service": "fb", "text": "→ If there is some way someone is coming from maine, you are welcome to my little honda eu2000 generator.", "timestamp": "1564225298"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103686827602&reply_comment_id=10100103761153652", "anchor": "fb-10100103686827602_10100103761153652", "service": "fb", "text": "→ Edward thanks! I don't think any of us will be, though, and we can probably find one closer if we decide we want a better generator", "timestamp": "1564225591"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103761348262", "anchor": "fb-10100103761348262", "service": "fb", "text": "Update:
* Peter is lending us a (traditional) generator as a backup
* I've ordered another 100Ah battery, which should be here in time but not 100%", "timestamp": "1564225725"}, {"author": "Aloysius", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103761822312", "anchor": "fb-10100103761822312", "service": "fb", "text": "The first Copley dance was Polaris with Steve Zacon
The folk folk arts center rented a generator", "timestamp": "1564226305"}, {"author": "Aloysius", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103761862232", "anchor": "fb-10100103761862232", "service": "fb", "text": "The dances usually run with a car battery it\u2019s inside this case and that\u2019s enough", "timestamp": "1564226356"}, {"author": "Aloysius", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100103761897162", "anchor": "fb-10100103761897162", "service": "fb", "text": "When that is not enough I take my inverter clip it onto someone\u2019s car battery they leave the car running next to the band and any device that draws too much power and plug directly into the inverter", "timestamp": "1564226426"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100104543231362", "anchor": "fb-10100104543231362", "service": "fb", "text": "Update: being outdoors you really do need a lot more sound, plus it was very windy. During sound check we were drawing about 200W when I hit loud bass notes, and the inverter would flake out. It would cut the power off, restart, and then cut off again the next time I got loud and bassy. This was disappointing, since the inverter is rated for 500W: https://smile.amazon.com/VertaMax-1000W.../dp/B06XPSF1D9
We ran the evening on Peter's generator, which did a great job.
I don't know whether I should fault the inverter for this? Naively it seems like it didn't do what it's supposed to, but maybe the momentary current draw was surpassing the 500W is supposed to be able to handle (and the 1000W surge rating?), and just was too fast to show up on my meter?
It does seem like we would have been ok for batteries. Even 250W solid for the whole time would have only taken one of the two batteries down to 50%.", "timestamp": "1564711010"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100104543231362&reply_comment_id=10100104543605612", "anchor": "fb-10100104543231362_10100104543605612", "service": "fb", "text": "→ One possibilty is I need fatter cables. I'm using the ones that came with it, but they're not that big and at 12V you need pretty fat wires.", "timestamp": "1564711150"}, {"author": "Jeff Kaufman", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100104543231362&reply_comment_id=10100104543695432", "anchor": "fb-10100104543231362_10100104543695432", "service": "fb", "text": "→ I don't really know a way to test this realistically without making ridiculously loud noises, unfortunately.", "timestamp": "1564711195"}, {"author": "Hollis", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100104543231362&reply_comment_id=10100104544583652", "anchor": "fb-10100104543231362_10100104544583652", "service": "fb", "text": "→ Build a soundproof room for your house.", "timestamp": "1564711819"}, {"author": "Peter", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100104543231362&reply_comment_id=10100104546215382", "anchor": "fb-10100104543231362_10100104546215382", "service": "fb", "text": "→ Jeff Kaufman Just wait for a neighbor to be using a leaf blower and no one will care about some bass notes at 200w.", "timestamp": "1564713184"}, {"author": "Edward", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100104570596522", "anchor": "fb-10100104570596522", "service": "fb", "text": "Yup.... bass=power", "timestamp": "1564744051"}, {"author": "Edward", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100104570741232", "anchor": "fb-10100104570741232", "service": "fb", "text": "Its not that the inverter couldn't handle the power, its the recovery rate. As I said, outdoors = more power. More power than you realize.", "timestamp": "1564744153"}, {"author": "Edward", "source_link": "https://www.facebook.com/jefftk/posts/10100103596688242?comment_id=10100104570960792", "anchor": "fb-10100104570960792", "service": "fb", "text": "Also, if the inverter needs a bunch of amps - 20,30 from the battery, the voltage from the battery will drop. If the battery reaches 10.5, it will cut out. Also if you are pulling more than a load 10%of the batteries capacity. In this case 10amps. You would be pulling 25 or 30.. the battery capacity drastically reduces.
Look up Peukerts law on load vs battery capacity.", "timestamp": "1564744536"}]}