I have a very simple circuit for a small RGB lamp I'm building. My plan was to power it off one of my many spare old USB phone chargers via micro-usb. It's just a string of 60 WS2812B LEDs with a NodeMCU as controller. I'm using a capacitor to smooth out the input power and resistor on the data line. In theory, the max draw from the LEDs is about 3.6A and the controller is somewhere around 200mA. With a 5V 3A phone charger, that should give me an acceptable amount of illumination from the LEDs while still suppling the controller enough power.
The issue I'm having is that my circuit is only getting around 350mA total. That's enough to run the controller and dimly light all the LEDs or have a few lit brightly. The brighter I set the LEDs, the more the voltage drops until the controller can't run. I've tried different chargers and different USB cables, but I seem to never get more than about 350-400mA. The circuit's really simple, so I'm guessing that's not the issue (showing it here in case I'm wrong about that). Is this an issue with the chargers limiting the current they send out? I know there are different ways the chargers 'advertise' their supply options, but I thought that was all on the supply side, not the draw side. Do I need to do something with the D+/D- pins to get the chargers to supply more current?