Segmentation and power injection of seed pixel strings

Hi everyone,

Back in 2010 I installed a 10m “Dream Color” LED strip kit from AliExpress on my roofline (two parallel 4.6m strips powered from the attic peak, no long leads or power injection needed). It worked great, but now I’d like to replace and extend the setup to ~25.5m and upgrade to pixel seeds instead of strips.

Goals / Requirements:

Pixel density similar to what I have now (30 LEDs/m).

Total length: ~25.5m.

Clean, weatherproof install on wooden soffits (no vinyl/tin to hide wires).


Current plan:

Use pixel seeds (though I hear 25–30mm pitch seeds can be tricky to solder/connect).

Run heavy-gauge power wire and a data line from attic peak to the start of the run (4.6m away). Extend heavy-gauge wire another ~21m to the far end of the pixel run.

Add small extensions in the pixel run at 9.2m, 14.4m, and 21.9m to get around corners.

Splice power injection at those extension points.

Use DIY connectors that allow splicing heavy-gauge and pixel power wires directly inside the connector body (to avoid dropping down to 18AWG like with standard xConnect pigtails and keep power/pixel lines evenly segmented).

Bundle power + pixel wires together with tape/heat-shrink for a clean install.


Questions:

Is this plan feasible for a 25.5m pixel seed run?

What gauge of power wire would you recommend for parallel runs — would 12AWG copper-clad aluminum be sufficient, or should I go heavier (solid copper)?

What’s the best way to construct and waterproof the connections/extensions/power injection points while keeping them neat and segmented for easy installation and replacement?

Any recommendations for connectors that meet these requirements, allow splicing power and pixel wires in the connector body and will work with the short tails of 25mm/30mm pitch seeds?

Any recommendations for reliable pixel seeds and AliExpress sellers? (Some strings advertise 20AWG wire, which seems helpful for voltage drop.)

Thanks a ton for your help!

You're only talking about ~1000 pixels here, where each draws 10mA, 10A total.
12AWG is plenty.
The "20AWG" rating is absolute lie. Most of the time that's 24ish if they say 20 on the seed pixels.
(But it's OK. You still get 100, maybe even 200, from PI points without any issues.)

As evidence see: https://scottledusa.com/product/seed-pixel-roll/

Where it says: "Copper Core: 0.16mm copper per strand (approx. 20AWG)"? .16mm(mm^2?) -> 25AWG, seems about right, certainly a lot closer to accurate.

Plan-B said:

Any recommendations for connectors that meet these requirements, allow splicing power and pixel wires in the connector body and will work with the short tails of 25mm/30mm pitch seeds?

Any recommendations for reliable pixel seeds and AliExpress sellers? (Some strings advertise 20AWG wire, which seems helpful for voltage drop.)

Thanks a ton for your help!

Click to expand...

If you know the length, get them custom made. Not much extra and it will save all the soldering.

You can also get Power injection 2core xConnects installed from the factory. Way easier than messing about with soldering on closely spaced seeds. You can also get custom length tails depending on your needs. Ive had some at 1m, some at 10cm. Whatever you want, they can make and ship to you very fast.


I've had custom made seed lengths from Ray Wu (Rita LED) and eTOP-led. Both have been good.

Thanks so much for the replies,

This leaves me with a few follow up questions and comments.

Merry mentioned that 12awg would be plenty. This is great as I kinda thought it would be insufficient. Checking with an online voltage drop calculator, I determined that 21m of 12awg aluminum wire at 12v/10a would have a ~30% voltage drop. I thought 10% was the threshold one should shoot for? Am I calculating the % wrong using the full 10a of the run? Do you think 12awg in overkill and I could go smaller?

Good to know that I should ignore 20awg seed claims and assume all are 24/25awg. This leave only IC as a deciding factor. For 12v I see WS2811, WS2815 and WS2818 commonly listed. I don't know if a redundant data line would be overly beneficial as if I blew a pixel, I'd replace the segment. I know with WS2811 strips, 1 pixel = 3 leds. Is that the case for the seed strings? Which seed string would you recommend?

Merry also mentioned injecting power every 200 pixels. My largest segment would be ~370 pixels with power on each end. I kinda thought I could get away with that as I have previously installed a 900 pixel / 3 WS2815 strip run in my kids room with power injected at both ends. This still looked acceptable at full brightness. I understand the seeds are much dimmer then strips or bullets so I'll probably want to run them a full brightness.

I thought about custom order strings as Johnny mentioned, but I'm leaning away from that for a few reasons. I'd like the stings in hand ASAP so I can install before the snow. With xConnect power injection tees I would still need to connect and waterproof the pigtails to the heavy gauge wire and I'm not sure how I can install xConnect on it. Lastly It would be nice to have the heavy gauge and pixel wires enter the same port on the connector so I can run them entirely parallel and bundle them together for the entire run.

I was hoping to possibly use connecters like the one linked below. My plan was to twist the power leads from the pixel string and heavy gauge wire together and then screw them into the same pin port on the connector, no soldering needed. This way I can run both lines parallel into the connector without the need for tees. I'm ok with burying a couple pixels in the connector as I can segment in software. I just need to insure I can strip the 25mm pitch pixels back enough to twist with the heavy gauge and insert in the connector. Do you think something like this would work?

Thanks again for all the help.

Right, so the current on average only goes half way across the roof, and the voltage therefore drop tapers off quadratically. (Also I assumed copper, not aluminum.)
12AWG may not be overkill though, depends how far to the run start.
The ICs listed are also not reliable:
"WS2811" is the part number of a discrete LED driver chip, way too big to be used in seeds, but it has become the term used to describe pretty much all addressable LED-like things that talk the same protocol.
"WS2815" is possible to use in seeds, but it's a 5050 (5mm x 5mm) module and a bit big for seeds also. Every seed I have dissected in the last couple years has been 4040, 4030, those sort of sizes.
"WS2818" is another discrete chip, not suitable for seeds.
So, you get what you get, but you can assume that if your controller works with "WS2811" it will work.
I did not say injecting every 200 pixels. I said a lot of mine run 200 pixels from power, which allows 400 if you feed from both ends. This does depend on the specific seed pixels and spacing used, whether they start at a full 12V, etc. If you do 370, try it first (better yet try 400) and make sure it's first in your string.
Seeds are a bit dimmer than typical bullets, but not much, and most of the dimming comes from the light getting diffused. They're on par with some strips, give or take the spacing and diffusion... the LED module tech is very similar to the strip tech, they're just soldered onto wires instead of PCB strips. But I never talk anyone out of full brightness .
Your connectors might work. But if I did it, I'm lazy, and I'd just get premade xConnect seeds, xConnect tees, and then connect an xConnect pigtail between the tee and the power wire. In the US, these are stocked for quick delivery, in Canada it might take an extra couple days, not sure.