# Using the WLED current limiter

**URL:** <https://wled.discourse.group/t/using-the-wled-current-limiter/14111>\
**Category:** Hardware\
**Created:** [February 25, 2025, 9:26am UTC](https://wled.discourse.group/t/using-the-wled-current-limiter/14111 "2025-02-25T09:26:55Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![wcndave](https://yyz2.discourse-cdn.com/free1/user_avatar/wled.discourse.group/wcndave/32/9337_2.png) [@wcndave](https://wled.discourse.group/u/wcndave)\
**Post date:** [February 25, 2025, 9:26am UTC](https://wled.discourse.group/t/using-the-wled-current-limiter/14111/1 "2025-02-25T09:26:55Z")

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I have a prototype setup with a benchtop power supply for a 5v LED strip SK6812 RBBW and a computer powering an ESP32.

The strip is 300 LEDs long.

The power calculator says I will need 14A.

Setting this up, with a limit of 10A in WLED, the benchtop supply shows 4.7A at 100% brightness (RGB+W), and WLED estimates 10A.

1. I am somewhat curious as to why the calculator is so far out. I get that all strips differ, however this is double, and I guess WLED uses similar calculation as its estimate is also double.
2. The outcome, is that to set a real value of say 5A, I need to set the limit to 10A which doesn’t feel very satisfactory or safe, and without the supply display, I won’t know what is really being drawn, and it could be real 10A which might not be good.
3. The calc says to put 3 power injections, however there is no drop off in colours, the lights will not go any brighter (as the power supply is capped to 10A also, and is drawing ~5A), so would I really need this?
4. I can imagine I would if I was putting too many amps through the wires of the strip itself, however there appears to be a recommendation to have one injector at 7.3A so I assume the strip wiring can handle this, and therefore a peak possible draw of 5A is fine?

Any advice greatly appreciated  
Dave

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**Author:** ![blazoncek](https://yyz2.discourse-cdn.com/free1/user_avatar/wled.discourse.group/blazoncek/32/1886_2.png) [@blazoncek](https://wled.discourse.group/u/blazoncek)\
**Post date:** [February 26, 2025, 8:21am UTC](https://wled.discourse.group/t/using-the-wled-current-limiter/14111/2 "2025-02-26T08:21:26Z")

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Measure single LED color (R or G or B) current when at full brightness, multiply by 3 then by count of pixels. That’s how WLED calculates.  
FYI W channel is not taken into account.

Once you have single pixel current consumption use custom value in LED settings.

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<div class="post-metadata">

**Author:** ![wcndave](https://yyz2.discourse-cdn.com/free1/user_avatar/wled.discourse.group/wcndave/32/9337_2.png) [@wcndave](https://wled.discourse.group/u/wcndave)\
**Post date:** [March 7, 2025, 9:31pm UTC](https://wled.discourse.group/t/using-the-wled-current-limiter/14111/3 "2025-03-07T21:31:32Z")

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According to the spec sheet, they are 18w per metre, which is 0.3w per LED, giving 60mA per LED. Multiplying by 300 gives 18A. Or 90w for 5m /5v = 18A

Yet I am only measuring 4.7A at full brightness from benchtop supply.

Is there some impedance on wiring or something that means I should be injecting at both ends to get full brightness?

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**Author:** ![kilrah](https://yyz2.discourse-cdn.com/free1/user_avatar/wled.discourse.group/kilrah/32/5927_2.png) [@kilrah](https://wled.discourse.group/u/kilrah)\
**Post date:** [March 9, 2025, 7:18pm UTC](https://wled.discourse.group/t/using-the-wled-current-limiter/14111/4 "2025-03-09T19:18:54Z")

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> **[LED power calculator](https://wled-calculator.github.io/)**

You need beginning, middle and end supply for 5m 5V.