Battery disconnected = end of life? (after 6 years)

[BillP]

hi there,

we have a SUA2200XLI running since 2011 (I'm working in this company since 6 months) and in the past nobody cared about it - it was always running well, so...... Since two days ago the UPS is beeping shortly every 5 sec. aprox  and the red light with the X inside the battery icon is flashing. battery level led's are off. sometimes it stops beeping and flashing and the battery charge leds are all green.... there was the powerchute installed on the server attached to the ups but the company who did the installation says there is no password (or better they lost it or won't give it to us....). I removed the old powerchute business edition and installed a new one, I wanted to know more before eventually replacing the batteries. powerchute says there are no batteries attached. Sometimes when the ups stops blinking and beeping the batteries are recognized as fully charged and battery voltage between 51 and 54 V.

So my question is: could this error (problem) be related to the battery that are at the end of life after 6 years? or should we consider a hardware failure?

thank you in advance for your help

[BillP]

Hi,

The description sounds like a battery issue however the battery voltage reading of 51 to 54 volts looks good. I suggest when time permits power down the attached load. Then hold the power on button for 5 to 6 seconds the prompt the UPS to run a self-test. if the test passes the batteries should be good. Another test you can run is with the attached load powered off plug a lamp into the UPS. Turn the lamp on and switch the UPS to battery by killing AC to it. Monitor the UPS to see if it will keep the lamp lit for a reasonable amount of time which will depend on the wattage draw of the bulb. 

If both of the test pass and the UPS continues to report disconnected battery then the issue is hardware. 

[BillP]

thanks bill, I will try to perform the two tests you suggested and see what happens.

thanks again, alex

[BillP]

Unfortunately at the moment I'm not able to perform the tests: the unit is continuously showing "batteries disconnected" - only sometimes the event log shows that the batteries were connected sometimes for a few seconds, sometimes for 1-2 minutes.....

I'm in real trouble, because we would like to avoid the purchase of 2 new batteries and have the same problems.

Any help or suggestion is really appreciated.

[BillP]

The UPS dose not recognize the batteries anymore, if I unplug the batteries an measure the output voltage with a MM, one battery says 13,5 V and the other one 19,9 V. Can someone tell me if this is OK? I would really like to avoid the purchase of two new batteries and then find out that the UPS has a failure.

Thanks

[Brad_C]

On 23/6/2017 3:54 PM, alex said:

one battery says 13,5 V and the other one 19,9 V

Unless I'm very much mistaken each of those "batteries" are a pair of 12V batteries taped together. Two of those blocks gives you ~48V nominal.

You should be seeing ~24V on each and thus I'd go out on a limb and say your batteries are toast and need replacing.

There are generally two failure modes of batteries.

A) They start to short internally, getting hot, swelling up and draging the UPS battery voltage down (so you can read that on the NMC). Sometimes you need to dismantle the UPS to get them out as they swell so much.

B) They lose plate material and develop a high resistance. The UPS thinks they are just fine as the float voltage sits right where it should be. You only know there's a problem if either the UPS runs a self test, or you lose power and notice the whole thing dies under load. High resistance batteries can intermittently show signs of failing self test.

The UPS has 2 tests for the battery. It frequently stops the charger and measures the battery voltage. It does this to detect the presence of the pack. A high resistance battery will often pass this test. The second test is the self test under load, where the ups tries to transfer onto battery. A high resistance battery *can* under some circumstances actually cause a load drop here as by the time the UPS figures the battery isn't going to cut the mustard, the load has already died before it can transfer back to mains. One to watch.

In your case it sounds like they've gone high resistance, and the standing test voltages confirm they're dead Jim.

[BillP · Accepted solution]

hi brad, thanks for explanation! I will try to change the batteries and hopefully get the ups working again.