Fast USB charging / Bluetooth® phone connectivity

One question that caught my attention on one of the forums…

When I plug in my phone with the USB cable I lose the Google maps voice directions on the phone. The phone displays a message when connected to the USB cable reading the audio is routed to the infotainment system. However, selecting the phone on the Infotainment system does not restore the voice directions. Any suggestions?

Apparently, his phone routes the audio to the Infotainment system properly via Bluetooth, but with a USB cable plugged in to keep his phone charged – nope.   Made me think of an impressive device that Mark Booth tested in the Mazda forum that not only disconnects the data portion of the USB connection, but also switches the device to fast-charge mode! That device is made by and is called a USB 2.0 Fast Charging Adapter.

  • One touch mode change (Data/Charger Switch)
  • Fast charge mode:  ⊗  Red LED
  • Data transfer/normal charge mode:  ⊗  Blue LED

By touching the switch on this device and seeing the red LED, your paired phone will be connected to your Infotainment system via Bluetooth, and audio for music and maps will be transferred as expected.  According to one user, all touchscreen, Commander panel and steering wheel controls, as well as the display, works perfectly as well.  Not sure what he means by “display works perfectly”, as I don’t think the map carries itself over to the 7″ display.  I’m assuming that probably is in regard to playing audio files.

Another advantage to using this device is that it will charge devices much better in fast-charging mode at the maximum capability of the port that it is plugged into.  Instead of the factory minimal ½ amp “charge” that our vehicle port normally delivers (USB 2.0 spec), Mark has measured the current throughput and reports that the output will nearly double to just under 1 amp, which although isn’t the 2.1 amps that true “fast chargers” are capable of, does meet the USB 3.0 spec, and even under a heavy processor load, it will indeed now be capable of bringing your USB device back to full charge.

Prior to my knowing of this device, even though my USB cable connected phone was in airplane mode, it must have been drawing close to ½ amp, as it would not actually charge if the screen was on and music was playing!


[UPDATE 9/3/2020]
John M has pointed out that this USB 2.0 device is no longer in production.  Our infotainment systems, although still functional, are already “old” technology – the USB standard, currently at 3.2 Gen 2X2, will soon be at 4.0.



☑ Another alternative method to charge your phone via the built-in USB ports, without linking the data circuits, is to simply use a power-only USB cable, like the short cables supplied with USB power banks (external backup batteries).   Mark has tested and posted that there are USB charge-only adapters that work out great (again boosting your charging to just under 1 amp) if you are using Bluetooth to connect the data.


For Apple products, he also recommends these charge only cables made by Portapow.


6 thoughts on “Fast USB charging / Bluetooth® phone connectivity

    • Thanks John. I’ll add a note to the article, and remove the link. At this point, as technology advances leave our infotainment in the dust, the alternatives involve either upgrading the USB hub, or obtaining a USB splitter so that your device can simultaneously be plugged into a better charger plugged into the 12 volt port, or a portable power bank charger.


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