I have two cheap (Amazon) 2-outlet USB chargers in the Cub. One in the panel and one in the left wing root. Both use a single breaker. Both show DC volts when energized. No noise. I see they now have USB-C versions on Amazon.
In the Cessna I have a 2-outlet cigar lighter tucked under the panel. It has a dedicated breaker and has a cheap USB adapter plugged into one outlet with a lightning cord for my panel mounted iPad. Also no noise.
I use generic charge ports that work on either 12 or 24 volts. Occasionally one will make noise (one out of 35 or forty) but usually trouble free. Also $20 vs $200+ compared to 'certified' ones.
I hard-wired in a couple mini/micro USB connectors I bought off Amazon for my ADSB-in and my tablet.
They're in use every flight- no static.
I also bought a cheap double-USB cigarette lighter adapter to charge my phone or whatever as needed,
rarely use it but it doesn't seem to produce static either.
Main reason I have it in place all the time is that it incorporates a voltage display.
I have two cheap (Amazon) 2-outlet USB chargers in the Cub. One in the panel and one in the left wing root. Both use a single breaker. Both show DC volts when energized. No noise. I see they now have USB-C versions on Amazon.
In the Cessna I have a 2-outlet cigar lighter tucked under the panel. It has a dedicated breaker and has a cheap USB adapter plugged into one outlet with a lightning cord for my panel mounted iPad. Also no noise.