08-08-2019 08:20 PM - edited 08-08-2019 08:34 PM
I have the T480, I bought it in November of last year. One thing I noticed since I first used it is that the second USB port (not the Always-On port) sends very little power to any device connected to it. It's quite annoying. The Always-On port can fast-charge even my most power hungry phones, I tested several. The second port pushes out 177.55 mA. I tested this on Android devices where I can see the power stats in real time. I've also tested on one of my iPhones, same result.
For the purpose of testing, I left the AC adapter plugged in (65w Type-C). There is nothing plugged into the Always-On USB, the only device plugged into the machine is the one I am trying to charge.
I'm up to date on all drivers, though as I said I've noticed this issue since day 1 and there have been plenty of driver updates since November. I have replicated this on one of my other machines, also a T480 with exact same specs. The USB port on the second T480 suffers from the same issue. I disabled the Always-On feature all together on both of the laptops and ran the same tests and got the same results.
Is this normal behaviour? Is this 2nd USB port supposed to be for functionality only? Meaning is it meant to be used just for productivity related items (that happen to draw very little power) such as mice, adapters, USB sticks etc? And is the Always-On port the one meant for charging devices? Am I making an incorrect assumption in expecting both USB ports to put out the same level of power (ie fast charge my phones on both ports)?
09-18-2019 06:30 AM
Thanks for reaching out. We would like to check if the chipset drivers of your machine are up to date? The latest chipset driver is 10.1.5.2. which is available for download here: https://pcsupport.lenovo.com/us/en/products/laptops-and-netbooks/thinkpad-t-series-laptops/thinkpad-....
Let us know if this works out.