I have a ESP32 with WLED installed and a 1 mtr strip of 60 addressable led lights.
I presently have it powered by x6 1.2v batteries via a 5volt regulator to the vin pin. The led lights work fine like this. I would rather have a more permanent power source to the ESP32 and leds, so I tried a 10 foot USB cable from a UK 3 pin USB plug adaptor. The said adaptor has x2 usb sockets rated at 5v 2.1A, but it won’t power the ESP32 and the led strip together. It does power the ESP32 on it’s own
Is this to be expected.
Thanks
How many amps does the led strip consume?
I dont think that 2.1amps in nearly enough… each LED uses about 50mA (on average as power consumtion of each colour is different)…and full brightness, so 60 LEDS would need at least 3A…
An easy way to check is in your WLED settings set the max current to 2000mA or less and the brightness will go down a bit but at least will work.
If you want to get really into the power consumtion calculations…here is a good site (with xls spreedsheet to help)
I miscalculated , thinking that 60 leds would only draw 1.2A . Doh! no they would draw more like 3A
It’s strange that when I tried a 12v 1,5A power supply plug through the 5v regulator , the led strip lit up.
thanks
12V * 1.5A = 18W
Assuming no loss in the 5V regulator
18W / 5V = 3.6A. Enough 
You have to keep an eye on some of those adapters too. Often they market it like it’s x Amps per usb port, whereas often it’s total for both.
Not that it sounds like this matters for your case (if you’re just using one?), but this shits me, so I wanted to mention it;) .
Take a look at the specs on the best quality phone charger you have?
Just looking on Amazon, there a 1 or 2 decent quality phone chargers which put out 3A, so they say…
My phone charger says: Output 5V=2A OR 4.5V = 5A OR 5V = 4.5A. So that looks like it will put out either 2A or 4.5A?
Who knows. That makes no sense.
No,it doesn’t to me either. Unless it was a misprint??
Actually, 55mA is the usual value taken for a WS2812 (3 colors) at full brightness white.
It practically uses far less power than that on average.
I’m def no expert, but I think some phone chargers can adjust thier output based on the device connected.
If the handshake is right they will output higher power…
Qualcomm 2,3,4 etc…
Those are actual protocols (QuickCharge, FastCharge, …) that both side must support, and ESP definitely doesn’t out-of-the-box.
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Don’t forget about the additional factors of the USB cable length and QUALITY of cable!
Very good article here:
Some of the better engineered USB chargers provide an output of 5.1 or 5.2v DC to counteract some of the losses across different quality cables, but at the end of the day it’s probably fair to say that USB-B types cables are not designed for greater than 2.4A at 5v (12W).
That’s telling you about the capability of the charger: It’s capable of negotiating higher currents ONLY if the device requests it. It minimises the risk of a faulty device or cable receiving 22W (4.5A at 5V) causing a short and fire.
I use a board like this one: Wemos ESP32 (ebay)
Then just connect a 5v supply (or 12v if you have 12v LEDs) to it. It makes the job easier.
I’ve given up on the USB idea and now use a 12V 1.5A supply via a LM7805 regulator, which works well.
thanks
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