After buying three power banks (none worked) I decided to buy a USB-C tester from Aliexpress (search for 32816538942).
The tester reports that my BMAX Y13 charges at 15 volts, not 12 volts like I thought it would. If I connect any of my PD power banks the BMAX negotiates 9 volts and it doesn’t charge.
And yes, it is definitely a BMAX problem. I…[Read more]