APC battery backup not working as expected.

I would like to ask you to initiate a chat with APC and let them configure device as per your requirement.

below is the link for chat support.
http://www.apc.com/site/support/index.cfm

What is the model of your APC unit?  It sounds like it is a surge protector and NOT and Uninterruptible Power Supply (UPS).  

Test:  Turn off your computer so that nothing is connected to your APC unit. Unplug the unit. Does it keep running?   It should start beeping.

Please let us know.  .... Thinkpads_User

Depending upon the model, you may have Surge Protection only receptacles.

Make sure your PC is plugged into a receptacle labeled "Battery Backup".

I have the model that looks like this ( I purchased from Staples) APC Back-UPS® NS 600VA 8-Outlet Power-Saving UPS.

Link to page is http://www.staples.com/APC-Back-UPS-NS-600VA-8-Outlet-Power-Saving-UPS/product_171432.

Thinkspad_user, i will perform your test when I get off work tonight....this is my home computer. But we have had such frequent power outages lately that I'm afraid of real damage to my computer, printer, etc.

That model has 4 surge only and 4 battery backup outlets. Did you plug your pc into "Battery Backup"?

Also, did you connect the battery as per the instructions before using the unit?  It is shipped with the battery disconnected.

It is supposed to be a UPS:

https://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=BN600G&tab=models&page_type=print

But is it really tiny. I have an APC 750-XL which is a very substantial UPS and does work during power outages.

The one shown above is only good for very small loads, so you may possibly be overloading it.

... Thinkpads_User

Note that the ES series do not make a true sine wave... they output a stepped approximation of a sine wave when running off the battery (the input wires from the mains connect directly to the outlets' bus bars; as do the charger/inverter input/output wires, on the ES models).

High-quality computer power supplies with active power factor correction (PFC) are typically not compatible with stepped approximation sine waves... they want to see true sine waves, like what you get straight from the wall outlet or higher-cost UPS units (e.g. my APC Smart-UPS 700 outputs a true sine wave... I'm not sure exactly what the price point is, where APC switches from stepped-approximation to true sine wave output, but I think ALL their Smart-UPS series output a true sine wave).

It's also possible the battery is getting bad. They usually last only 3 years or so... it's typically a single sealed lead-acid 12V with 1/4'' terminal tabs in the ES series... here's what I put in an APC ES-500, which had a dead battery, last year - http://www.newark.com/enersys/np7-12-250t/lead-acid-battery-12v-7ah/dp/52F5901

I connected the battery as per instructions. I may have used the "battery" outlets as well as the "surge" outlets for connection. I didn't know there was a difference. How can you tell?

On a real UPS the AC outlet is protected. Look in your documentation for which outlets to use. I expect it should be the Battery outlet.  

... Thinkpads_User

Also, should I plug my PC into the surge or the battery outlets? What's the difference? I'm a total newbie regarding this, as you can tell.

You should plug the PC into the Battery Outlet. The surge protector outlet probably is not on the UPS side but your documents will tell you. Surge protection is just that. UPS protection is for power outages.

Please test your device (as I suggested earlier). Turn off the PC, disconnect it.  Now additionally, plug in a 60 Watt table lamp into the Battery outlet. Unplug the UPS. What happens?

... Thinkpads_User

@sheana11 - We have asked you to look in your manual to verify what outlets to use and also to test the unit so we know if it is working.

Any progress?

... Thinkpads_User

Thank you for the graphics, it really was very helpful.

You're welcome. Happy to help. Regards, Joe