I'm trying to figure out what's the best way to power a 64x32 RGB LED matrix and an ESP32 WROOM 32D using both a power bank (some 18650 2000mAh 3.7V in parallel + voltage regulator) and USB C (5V 3A). I would like to rely on the power bank when I need portable operation but I also want to be able to power them using an USB C cable (coming from any kind of power adapter capable of 5V 3A) when I have a wall socket available.

From my estimations, 5V 3A would be enough for what I'm using the matrix. Just in case I would need more current at some point, is there any way I can get more than 3A from USB C?

  • \$\begingroup\$ How ae you going to MUX this large an array when the Imax / I rated ratio is only 1.5 \$\endgroup\$ Commented Mar 24, 2021 at 11:21
  • \$\begingroup\$ Being a newby here I'm not exactly sure how to answer your question @TonyStewartSunnyskyguyEE75. The ESP32 drains around 100mA, leaving the rest for the RGB matrix panel. As long as I don't need to power on all the LEDs at maximum brightness, the amount of current left has to be more than enough. \$\endgroup\$ Commented Mar 24, 2021 at 11:48
  • \$\begingroup\$ Well the answer is you have to decrease the peak maximum current by the number being multiplexed so the average brightness is also reduced. Your simple concept can work yet dim. \$\endgroup\$ Commented Mar 24, 2021 at 13:17

1 Answer 1


For more than 3A from usb compliant chargers, you need usb pd and 5A capable emarker cables. For more than 5V at xA which you can then regulate down to 5V yA but use regular cables, you also need usb pd plus a regulator. Both cases would require you to add a usb pd capable microcontroller or dedicated PD enabling IC. You can get trigger modules that do this for you if you don't want to add/design your own board.

Non-compliant chargers or USB A chargers may allow you to pull more than 2.1A directly from the port as these tend to be simple 5V regulators directly tied to the usb connector. There is no charger side control of the power out. USB C chargers should have active control circuitry that enables higher current and/or voltages. But with non-compliant usb A chargers and pulling too much current, you will see voltage droop at best over cheaper usb cables with thinner cables. Worst case is a fire from overheated cables.


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