UPS will not power computer during power failure

[severach]

Re: UPS will not power computer during power failure

This UPS isn't intelligent enough to determine that the battery is dead if it won't power the computer at all.

I haven't found any small ones that are. Seems like an extra 2 penny chip would solve this problem. They just shut down once they try to power from a dead battery even though power continues to be available at the plug.

I got rid of all my UPS for this reason. I found that original batteries last about 5 years. El-cheapo replacements last about 3. Because they can't detect, lock out, and alarm bad batteries and they switch to battery any time a small voltage drop comes across the line, a UPS with a battery at the end of its life causes constant computer outages. To prevent failure I decided that I would need to replace the batteries every half time interval or 1.5 years. 1.5 years times a few dollars is... too many dollars per year on top of what I already pay the Power Company for outages.

How terrible must a designer be to design a UPS that causes the very problem it's trying to solve? How dumb must a customer be to buy a product that causes... and this time that customer is me!

To me a UPS is useless without dual power supplies. One runs from the UPS and one runs from the wall, on a different circuit for a high reliability installation. That way the UPS can go off as many times as it wants so long as I catch it by the next real power outage.

[kc8adu]

Re: UPS will not power computer during power failure

many good small ones do indeed test their batts.one of my old apc units kept alarming for a bad battery.being a big external i load tested it.was fine.measured at the ups with the inverter running no load.10.8v!at battery 12.9.
i had a bad solder joint in a powerpole lug.reheated with a torch and problem solved.
my old weller gun couldnt get things hot enough to do the job.and you cant see down into the lug!passed the pull test.but must have been only a few strands of that #4 wire making it.

[Longbow]

Re: UPS will not power computer during power failure

The metal APC SUA SmartUPS series produce a sine wave output which is what our PSUs are designed for.

Off hand, I'm not aware of any supplies that specify that a square wave input is OK.

They're big, very heavy and expensive but get the job done.

Yes, just think about the size of the parts necessary to act as low pass filters at 60 Hz. As the current requirements go up, so does the wire size and the core size, etc. There is a good reason why they are so expensive. I don't know why anyone would risk feeding computer equipment with square waves because that is just asking for trouble.

[pentium]

Re: UPS will not power computer during power failure

I have a SmartUPS 700 and I don't even bother hooking more than the system and router to it because it's already at 3/4 load. If the power goes out, just remotely login and gracefully shutdown in ten minutes or less or else the system powers itself down regardless.