Fluctuating Charge, Zero Runtime

[Anonymous user]

UPS: SU1400RMNET

This UPS exhibits some behaviors that I simply cannot figure out. I've done extensive research on this and am hoping that someone can help.

First, the battery charge level fluctuates even when full power is available. It commonly fluctuates between 100% and 80%, and I have seen it run the batteries dead and actually shut the attached components off--all while there is not so much as a flicker on our power. We have multiple other UPS's attached to this same power and we don't get so much as a beep from them.

Secondly, it has zero battery run time. Trying to figure out my issues with this unit, I charged it for a full day and a half. During that time the battery level did fluctuate between 80% and 100% a time or two, but at the time of my test it was at 100%. I attached a 20% load (280 watts of light bulbs) to the output. Before I unplugged it, I re-verified that I had 100% load and that the green light indicating normal power was lit. The moment the plug was pulled the lights went out and the UPS went dead as if it did not even have batteries. I plugged it back in and after the self test it showed 60% power. I have never seen the replace batteries light lit.

The batteries are about 3 years old but this UPS has exhibited this behavior since the batteries were new. I had an identical SU1400RMNET before this one and it exhibited similar behavior. Help! I haven't checked the battery constant but I can do that. It just seems strange that it wouldn't hold power for so much as a second.

[Techie_apc]

Chris,

This is most likely the battery issue. However, I would like to gather some more information in order to provide you any recommendation. Could you let us know the UPS serial number? Did you replace the original batteries? If so, did you replace them with APC genuine RBC or third party batteries? If possible, could you please post the event and data logs of the Power Chute software? Do you have any other Identical UPS with working batteries?

[Anonymous user]

Serial Number: FS993000593

Batteries were new when the UPS was purchased. Not APC RBC, but a good brand (EnerSys Genesis NP7-12T x4)

I am certainly willing to consider that this is the batteries, but it has done this since the batteries were new. But a few things make me think that there is some other problem(s) (even if the batteries are weak.) First, the replace batteries light is not and does not light. Second, one would think that even very weak batteries could support a 20% load for a few seconds.

I do have other UPSs with identical batteries but they are all ready to be replaced so I wouldn't necessarily trust the results. I should probably just buy new batteries to rule that out but was hoping to find avoid buying batteries for a UPS that is irreparable.

I just repeated my battery runtime test with a single 90 watt light bulb. Again, the same result. The instant I pull the plug the light shuts off. I looked at the front panel and it shows 5 LEDs (100% charge) with the 120v plug pulled and the bulb switched on (but no power to the bulb.)

I'm sorry that I don't have any logs to provide. I just got serious about trying to resolve this problem and downloaded/installed the Powerchute software. I can repeat the tests with the software running, but obviously I'll have to plug the computer in elsewhere.

[Techie_apc]

Chris,

If the battery bar lights are flashing when the unit is on AC power, then please have a look at this [K-base|http://nam-en.apc.com/cgi-bin/nam_en.cfg/php/enduser/std_adp.php?p_faqid=1497] to rectify this situation.

Secondly, I would replace this old UPS which was manufactured in 1999 to a new unit instead of replacing the batteries. You may consider the [Trade UPS program|http://nam-en.apc.com/cgi-bin/nam_en.cfg/php/enduser/std_adp.php?p_faqid=298] to purchase a new unit.

[Anonymous user]

I don't recall that the battery bar lights were ever flashing. I ran Powerchute and have the following with the unit on line power, batteries showing 100% charged, and zero load:

UPS Load: 0.0%
Runtime Remaining: 302 min
117 Degrees F Internal Temperature
122.2 VAC Line Voltage
99% Battery Charge
27.2 VDC Battery Voltage

I then turned on my 280W of attached light bulbs and got the following:

UPS Load 30.1%
Runtime Remaining: 38min

Again, everything shows fine. And I'm sure you're giving wise counsel but I'm hoping to find something that I can fix so that I can re-use this UPS. This is for a very small wiring closet and normally the only thing running on it is a couple of 8-port switches. I kind of hate to spend a bunch of money on a new UPS.

Message was edited by: cmyer

Message was edited by: cmyer

[Techie_apc]

Chris,

hmm..the Power Chute shows that the UPS runtime remaining is 38 min. Did you test the UPS runtime by unplugging it from the wall again? If so, did it support the load on battery?

[Anonymous user]

I think you're seeing the dilemma now. Every time I test I get the same results. The INSTANT I pull the plug the lightbulb goes out. Matters not if I have 280W or 90W. The one difference in the results is whether or not the UPS itself shuts off. Everytime I've done it with the 280W load the UPS goes off completely when I pull the plug. No lights on the face, no communications with Powerchute. Once, when I only had 90W attached the light bulb went out immediately as normal but the UPS itself stayed on. The battery charge even showed 100%. Plug it back in and everything looks/acts normally.

[Techie_apc]

This is an abnormal operation..If possible, can you check the UPS with other identical batteries and check if that makes any changes in the operation?

[Techie_apc]

hmm..there should be an internal fault with the UPS circuitry if the UPS shutdowns completely even with good known batteries when you unplug it from the wall.

[Anonymous user · Accepted solution]

Battery swap did not help. UPS exhibits the same behavior. Any other ideas?