Back-UPS ES 750 allowing computer to shutdown during voltage problem

[Anonymous user]

I have a Back-UPS ES 750 that has been working great for quite some time. I have a Windows XP workstation and Dell 20" LCD monitor plugged into the battery portion of this device. Here recently I have been coming home to find my computer turned off. I'll check PowerChute after starting the computer back up and it does not mention anything about a detected problem. One day I was sitting at the computer and all of a sudden it just turned off. The electricity in the house did not go out, and all the devices plugged into the Surge portion of the device continued to stay on. I imagine it detected some sort of electrical problem and tried to switch to battery. Does anyone know what would cause this?

Thanks!

Message was edited by: WillJitsu

[BillP]

yes, the battery will be covered under warranty.

[TheNotoriousKMP_apc]

Will,

Have you checked the Windows Event Viewer log? Normally a shutdown would be located in there as well.

I experienced something similar to this when I was using a BX900 (Beta). The Transfer Relay Weld failure caused my UPS and PC to power down unexpectedly. I suspect that could be what it is.

[Anonymous user]

I did check the Event Viewer and did not find anything out of the ordinary. I did not find any references to shutdowns at all. This all started after a power outage we had at the house a few weeks back. It killed our other Back-UPS ES 750 unit and another computer that was plugged into a regular surge strip. I thought mine had survived since it still powers up my computer just fine. It's just no longer switching to battery when a voltage problem occurs.

[BillP]

Would you be able to provide the serial number of your UPS, or at least the first 6 characters from the white serial number sticker, or even from the Technical Specifications page in PowerChute Personal Edition?

It would be interesting to know if the UPS would support a smaller load, perhaps a lamp, in a simulated outage scenario (pull the plug from the wall with lamp in the battery backup side).

[Anonymous user]

Sure. The first 6 characters are 3B0645.

I'll do a simulated test with a lamp when I get a chance and post the results here.

Is there some sort of battery test you can run on these units to see if the battery is just dead?

[Anonymous user]

I was able to do some testing with the UPS.

It was able to handle the switch from AC to Battery with a lamp.

It was able to handle the switch from AC to Battery with my 20" LCD monitor.

It was NOT able to handle the switch from AC to Battery with the computer and monitor. Both the computer and monitor turned off immediately. This has never been a problem for it in the past, so I'm not sure what is wrong now. It has always been able to power them for several minutes and then perform a managed shutdown.

Any ideas?

[BillP]

you can measure the voltage off of the actual battery with a voltmeter.

this unit is still under warranty, so if you need a battery, you can call into support for one if you find out that the voltage is extremely low.

to me, it sounds like a battery at this point. the fact that it transfers to battery correctly and supports smaller loads tells me that the unit itself is working fine but maybe the battery capacity is poor..it may be only at a fraction of its original capacity (even though the battery may report 100% charged).

[Anonymous user · Accepted solution]

Yes the software is showing 100% charged. Are the batteries covered under warranty or would I have to purchase a new one in this case?