What do you use for powering massive LED projects? I’ve just worked out that the device I’ve been asked to help with will have about 750 LEDs, for a total peak draw of ~40A at 5V. The available power sources to me are either a generator or deep cycle 12V batteries. The batteries would be preferred. Should I be looking for 12V to 5V converters? One big one or several smaller ones? Any suggestions are greatly appreciated!
sigh
Static or wearable/portable installation?
If you want to power yourself off car (really deep-cycle marine) batteries, see if you can use 12V strips/strings (I posted an example earlier today; dig around on Ray Wu’s Alibaba site for more.) If you can’t find suitable 12V strings, I would use multiple of these 125W DC-DC modules distributed around close to where you’re injecting the 5V to the strips:
http://m.aliexpress.com/item/1675239768.html?tracelog=storedetail2mobilesitedetail
Derate to the point where any one of them can blow up and the remaining modules can pick up the slack and stay within spec.
It’s a static installation. Do the 12v strips efficiently convert to the needed led voltage, or does it just use a current limiting resistor? I bought 5v strips. They are in the mail as we speak.
Of that I’m not sure. Many of the 12V strings have 3 LEDs per pixel, so they use (most of) the 12V. But if you’ve got 5V strips on the way then yeah, look at those DC-DC converters.
Thanks for the advice. I’ll take a look at that convertor and similar ones. I had trouble finding any outside the 5-10A range.
I found some reasonably priced 5v20A converters on amazon. Bought three, which should be more than I need. The question now is should I parallel all three or distribute them such that each one sees roughly 1/3 of the LEDs.
What platform are you planning to control the ~750 LEDs from? Due or Teensy3.1? You’re gonna need some horsepower to get a decent frame rate with larger amounts of LEDs, and some LED chipsets are just slow for larger installations. I am merely saying this out of boredom, as I’m sure you probably already know this 
I’m using a Teensy 3.1 with the OctoWS2811 shield. I was planning to make my own boards, but I couldn’t come close to the price of those…it seemed worth it, at least for my first project with this kind of hardware.
I’m still debating between the OctoWS2811 software and FastLED…choices, choices.
Nice, the Teensy is small and powerfull. I guess it comes down to usage, really. What LEDs do you plan on using?
WS2812B strips, 60 LEDs / meter. They’ll be going all the way around an 8’ diameter circle, and down four legs towards the center. (It’s a giant peace sign). Did I mention that it’ll have a fire breathing dragon on top, creating massive fireballs? I should probably mention that…
Always mention fire breathing dragons…always 
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@Buddy_Smith I wouldn’t run PSU’s in parallel. Distribute the load evenly across them. Running them in parallel can cause all of them to blow if one fails (since the others are now taking up toe load for the missing one.) With a distributed load, if one fails, 1/3 of your installation will go dark but the others won’t get affected. 2/3 working is better than none at all.
That’s what I was thinking as well @Ashley_M_Kirchner_No . I’ll split the LEDs roughly proportionally across each supply, and try to come up with a way to redistribute the load in the field if one of them dies.
It never hurts to have a spare PSU. Murphy can be a bit of an ass some times …
Two of these should be able to handle all LEDs on white at full brightness, at which point my batteries won’t last very long! I’ll wire in three supplies, to have some head room. If one of the breaks, I’ll just split the load between the remaining two. If two of them break, I won’t use full power until I can get back to the lab and figure out what happened…
Can we get a link to the 5V 20A DC-DC supplies? I’m interested in that too.
Here’s the one I bought. http://www.amazon.com/gp/product/B00JGISHQQ/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B00JGISHQQ&linkCode=as2&tag=leftventcom-20&linkId=L3WQAW2IBR4BSDVT
I haven’t tested it yet. I’ll update this post after I have a chance to try it out.
I just picked up one of those smakn converters last week, haven’t asked heavy load of it yet though. I’m very curious how much these differ between suppliers, being encased in resin it’s impossible to see of what quality components are used.