The calculator is correct. However your inputs are not. You do not have standard WS2812 LEDs. The webpage sais 0.1W per LED, with 300 LEDs that would be 30W (6A) not 55W (11A).
Also these strings are not made for full white without additional injections. Reduce the power to your use case. A 1mm^2 is probably good enough, you can increase it if you find its not.
Thanks, I don’t really understand the white led comment, but I understand the stated draw of the individual LEDs…
I’ll stick with plan a and use 4 of the 5 cores for power allowing me to effectively run individual cables for each end.
It looked pretty good running off the power it could pull through my esp limited to 900ma so goodness knows what it’d look like if it was given more power!
I think the comment about full white is stating that running full brightness RGB white is not a great use case for your particular strip. That lights each color channel of each led and thus draws a significantly higher amount of current than any animated effect. Using full brightness RGB white would necessitate additional power injection.
Tl;Dr RGB white uses a lot of juice. If you’re not planning to use RGB white ignore this entire comment.
I am still abit miffed - I have a ancient history is electronics - so may be a little knowledge is dangerous.
But… I have tried two Power supplies on various LED strips -in additional to this one. (A 2a and a 4a)
In one case I had power at both ends of a 2.5 metre strip of SK6812.
The white was so bright I couldn’t look for an extended period… And yet the draw from two measuring devices didn’t go over 0.1a - wled reckoned it should be using 17 odd and if I turned the limiter on any less than that… I could see it applying a dimning - but like I say the draw was tiny.
The only explanation I have is that is a ac/dc thing… Because if these LEDs are that bright on a tiny fraction of what they could draw… And if they could take more why weren’t they? Even with 2 injections points…
I would ask:
How are you measuring the “draw” of your LED’s
White “too bright to look at” sounds like you’re getting power to the LEDs.
Measuring what you’re actually drawing will need an ammeter inline with the power cable, preferably right at the power supply.
You want the meter set to DC A and you want all the power going through the meter.
Literally this morning (with the help of my uncle; Hello UNC if you ever read this…)
My measuring devices were measuring the AC not the DC and a lack of full appreciation meant that although I had mused on it… I’d forgotten to explore/research fully.
But allowing for watts to be constant at 30 (in my case) and volts to be 5 that means that it must be 6 amps on the dc side.
This is further born out by the fact that 5v is 48 times less that 240 - and assuming a theoretical 100% efficiency, a current of 0.12a on the AC side… of you apply the same factor of 48x gives us 5.78amps which is almost exactly what I am expecting to see.
I’ll get myself a new multimeter that can read amps for Christmas!