Automatic brightness limiter confusion

Let’s say i have the following:

one 5v 60 LED/m WS2813 strip, 5m long. spec: 60 ma/pixel 18watts/m
24v power supply
5v. 15a step down convertor

I want to limit the current draw of the strip to 7 amps. I attached only one power connection with short 22a wires on the stock solder points in the middle of the 5m strip.

In the ABL settings i enabled the automatic brightness limiter and set it to 7000ma and 60ma/pixel. Is this correct?

Also when I test amps with a multimeter on zero, it reads approx 3.25a between convertor → psu and reads approx .45a between convertor → led strip. These two values never change no matter what I do - enable/disable ABL, min/max brightness levels, set white or any RGB color. roughly the same values.

  • Consider using thicker wires, such as 18AWG or 16AWG, which are better suited for higher current draws. This will ensure that the wires can effectively carry the required current without overheating or causing voltage drops.

  • Use a more powerful step-down converter, such as a 5V 20A or 25A model. This will provide a larger current reserve and ensure that the converter can handle the demands of the LED strip.

Something is wrong with your description, your measurements, or both.
When using a buck converter (properly) the current on the high voltage side should always be less than the current on the low voltage side.

If you want to really test the ABL, tell it you have a 2000mA (2A) supply.
Then set your brightness to 10%, set the colour to all white and try to slowly increase the brightness level.
At some point you’ll see that the LEDs will stop getting brighter no matter what you do with the master brightness.

You can get some idea of what’s going on by clicking the Info button to get a read as to what WLED thinks your LEDs are currently drawing.

Remember, all of this ABL stuff is just fun with numbers, WLED doesn’t measure any current draw it just calculates what should be happening based on the colours and brightness you ask it to display. If you dead short your power wires from your supply, they’ll still pass as much current as your power supply can deliver no matter what the ABL says. WLED has no idea if your wires or LEDs are melting, it’s not a safety feature it’s just a relative convenience.

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I’m a bit uncomfortable setting ABL emperically. I’d much rather understand range and limits for the setting from a mathematical perspective.
PSU: Altove 12V, 30A
LEDs: ws2811 strings (50 LEDs/string). Total 850 LEDs
Power Injection: beginning & end
All LEDs are currently lit.
ABL Max Current Extimated usage Observation
1000mA 988mA very dim
1500mA 1492mA dim
2000mA 2000mA dim, but acceptable
2500mA 2489mA dim, but acceptable
3000mA 3006mA decent brightness
3500mA 3472mA same
4000mA 3982mA same

Is there a point where I push my PSU too hard? Help me understand optimization of range and limits for this ABL setting.
Thanks

See your other post for more details on doing measurements.
The math/range limits of the ABL come (crudely) from trying to match the real world measurements, not the other way around.

You need to know what’s actually going on with your strings, not what you can guess from what it looks like.