Originally Posted By: buckeye

One unexpected problem I ran into last weekend: I recently purchased a small back-up UPS for my Cable Modem and Router. When I went to test it, my interal home router ran fine but the Cable modem won't run off of the back-up. Talked to the cable company and it seems the frequency generated by the battery back-up may be outside the tolerance (to far outside of 60Hz) the cable modem wants to see. (I probably didn't say that technically correct, but in short, they don't work together). I've read that more expensive units may do a better job and I believe a few even come with guarantees.

So, like any piece of our equipment, be sure to test it before you need it.


Yah, a lot of lower quality UPSes don't provide clean power.

Another gotcha with UPSes is that a number of them will not allow you to turn the UPS back on after you turn them off. This can be problematic if you are trying to conserve your power.

Also, make sure your unit has the ability to silence the power outage alarm. Of course, you can open the unit and physically disconnected if you are comfortable doing that.

-john