USB Port Amperage

[sparkycar3141]

I believe the USB port in the center armrest storage is underpowered, charging my iPhone 6 is quite slow, especially when letting Waze run it pretty much just holds the charge.

I recently changed from a 2015 M3 to the 2017 i3. The M3 did not have this issue. Well, I decided to get some hard data and bought a USB diagnostic module that measures the voltage / amps. Here's what I found so far...

All tests with iPhone 6, USB Lightning cable.

AC Wall Charger = 5v / 1.37a
12v USB adapter plugged in under the i3 dash = 5v / 1.1a
USB in center console = 5v / .46a

So basically less than HALF the power of the 12v adapter under the dash.

I searched all over within Bimmercode, couldn't find any setting for USB max power. Hope to try it out in another i3 soon to see if it's just mine.
Anybody else noticed the same?

I know I could just use the 12v charger and listen to music via Bluetooth but for some reason the USB wired connection sounds better to me.

Thx!

__________
2017 i3 REX

 

[alohart]

Early USB 1 and 2 specifications set the maximum current for a low-power outlet to be 100 ma and for a high-power outlet, 500 ma. It seems that the i3's USB data port conforms to the old USB 1 or 2 specification. As many have reported, this port is underpowered for charging a smartphone, but likely meets the USB spec.

 

[sparkycar3141]

Yep, that must be it. Apparently my wife's car and my old M3 must either be following USB 3.0 spec or just ignoring the spec to provide more juice.