Thinkpads Forum

I'd like to run an external HD from one of the USB ports on the W520.
Lenovo's manuals don't show the amperage of these ports. What is it for each?

Thanks.

Ellen

2.5 inch drives will work as long as the connecting cable is of sufficient "gauge"..
i believe that USB is limited to 2 amps..

i have not seen a 3.5 inch drive that can be connected to and powered by any USB port..

as for manuals, have you looked at the hardware maintenance manual for your W520..?

I don't think I've ever had a problem using an external 2.5" drive with Thinkpads.
Sometimes my Dell's don't have enough power for some drives though.

Thanks, Bill and Jdrou. Knowing the drive size that will work helps.

No info in the hardware maintenance manual that I could find searching for
USB 3, mA, amp, amperage, and so on.

i called Leveno to ask before posting here and the guy I spoke to said, that info isn't on the sheets they give us. I asked if he could check with someone and after a long time came back and said ".5" but when I asked if it was the USB 3 or USB 2 ports, he only said, that's all they told me. This info should be in the specs, I think.

Ellen

Standard USB is 500mA. (0.5A) 2.5W. That's why some external USB drives come with dual USB plugs.

Some computers provide more than USB spec - notably Apple. The "yellow" port might do that, but I've never seen it in writing.

Pretty sure most laptops provide more than the required 500mA; only question is how much more? I think most 2.5 drive specs say they need close to an Amp to spin up. On Thinkpads I don't normally need to use an extra USB connector for power.

jdrou wrote:Pretty sure most laptops provide more than the required 500mA; only question is how much more? I think most 2.5 drive specs say they need close to an Amp to spin up. On Thinkpads I don't normally need to use an extra USB connector for power.

Most probably do provide more, but all are required to produce 500 mA *after* host negotiation. Without it, it's 100 mA (IIRC).

None of my thinkpads provide much more. An Ipad refuses to charge unless the USB port provides 800-900mA. My iPad won't charge on my W500.

There was a known hack a while ago for charging iPads involving a Gigabyte motherboard EXE that would somehow, automagically increase power. Not sure how safe it was or where it is now though.