Battery Power is too low to support the load : Smart UPS 3000VA RM

[Anonymous user]

Dear All,

I have a SmartUPS 3KVA RM feeding our servers. The network management interface shows that the load is 39% and the battery cpapcity is 100%. When I power up a new box which I just connceted to the UPS the following happens and the NMI initiates a shutdown:

"08.01.2009 17:35:08 UPS: A discharged battery condition no longer exists.
08.01.2009 17:34:44 UPS: The battery power is too low to support the load; if power fails, the UPS will be shut down immediately."

I could see the battery indictor on the UPS flashing green (no it does not turn yellow) the momemnt I power up the new box. I got "UPS: A discharged battery condition no longer exists" once I powered down the new box, before the NMI/UPS initiates a shutdown.

The battery is fairly new battery which was installed in last October.

I first thought that batteries are not getting charged for some reason, but then I sould not see a100% battery capacity, should I?

Thank you for your help.

[BillP]

Hi:

What does the remaining runtime indicate on your NMC? Also, what is your "Low Battery Duration" setting set to? You can find this setting either under Smart-UPS - Configuration, or under UPS - Shutdown (depending on the firmware rev). When you replaced this battery, did you replace it with an APC RBC?

It sounds like either that setting may be too high, or the runtime may be read inaccurately and may need to be re-calibrated.

Let me know and we can help you resolve this.

Thanks,E

[Anonymous user]

Hello CMFR,

Thank you kindly for you post.
1. UPS/NMC settings:
"Low Battery Duration" set to 02 minutes and "Shutdown Delay" set to 90sec
2. "Remaining Runtim" showing is 6 minutes
3. Yes, the replacement battery was a APC replacement battery.

Thanks and Reagrds

[Anonymous user]

39% load and the runtime's 6 minutes, on new batteries? Something's wrong.

I looked around and found a SU3000RM here with 36.4% load, batteries about two years old, and it's estimating 18 minutes run. Yours ought to be 20 or more, IMHO.

The "recalibrate" suggestion is good, of course. However, usually I've found other things to be wrong. Note that if you recalibrate and something's wrong, you might find your load dropped, etc.

If you have the older, non-2U variant of the RM, one of the most common things that causes problems like this is someone managing to knock off a battery wire while installing the batteries. From time to time, we find a connector that's not quite as tight as it might be. If you lose a wire, the RBC will appear to continue to work, because it is a pack that has two batteries in series, and two sets in parallel. You go down to one set in parallel, and suddenly your 3000VA UPS becomes something more like a gimped 1500VA. That looks vaguely like your symptom.

The other thing to consider is the source you used for the RBC. Sadly, SLA batteries have a relatively short shelf life. I know that many companies like to shop for batteries based on price, but in the case of something like the RBC12, you don't necessarily have a lot of people buying them, and are you sure it hasn't been sitting on a shelf for six months? The end result will be batteries that severely underperform. The battery pack of an RBC12 is, of course, the same as the battery pack for the RBC8, just without the fuse wiring. This always annoyed me a little bit, from an end-user point of view, it'd be easier to guarantee freshness of your RBC if there weren't as many models.

You might want to see if you can identify a datecode on the batteries. For example, Yuasa/EnerSys Genesis batteries typically are marked xYMMDD, and if the batteries were more than maybe nine months old when you bought them, that's going to have a negative impact.

[Anonymous user · Accepted solution]

Hello jgreco,

Sheduled a service interruption to inspect the battery pack yesterday. The batteies carried a data stamp of 0031022, which I interpreted as made in 2003, since this UPS has been bought in mid 2004 (in Australia). Then I found out that it was the NMC which had been replaced last year not the battery pack!

I have two queries:
1. As you correctly thought it is the old style 3000VA RM. I just looked up one of our supplier wbsite for the replacement battery pack. Is RBC#43 the correct replacement for this? Connections in RBC#12 seems to be a bit different from (going by the picture there) what we have. Or can I just buy RBC#12 for me to re-wire the 4 batteries into the enclosure? - is there any warranty complication with this approach?
2. What is the best way to re-calibrate the UPS once a new battery pack is installed? If it is with a calibration key, how can I get one? Have you got to order one from APC AUS or does it come along with a battery pack?

Thanks for your help.

Regards