Did you look at nut? (http://www.networkupstools.org)
It's in pkgsrc.
I'm not sure but I think they now support some USB models.

JL

Sean Davis wrote:

>Hello, I just recently acquired an APC Smart-UPS 1500VA from a friend,
>and the only cable it came with is the USB cable. The kernel
>recognizes it, but apcupsd's USB driver won't build on NetBSD. Is
>there any way for me to communicate with the UPS short of building one
>of those wonky serial cables for it? Sure, you can talk to the HID's
>with usbhidctl, but that's pretty useless as far as monitoring the
>power goes.
>
>Any help would be appreciated. TIA
>  
>