Back-UPS CS 350 reports Battery power exhausted immediately on power failur

[Anonymous user]

Hi. I've got a Back-UPS CS 350 connected to a computer running Linux and apcupsd. The problem I'm having is that twice the last month, the UPS has switched to battery backup and then immediately turned off, killing the computer before it has time to shutdown properly. I haven't noticed any power outages during these times, since my other computer (not using an UPS) kept going.

apcupsd reported the following events:

Wed Jun 22 04:07:39 CEST 2011 Power failure.
Wed Jun 22 04:07:40 CEST 2011 Battery power exhausted.
Wed Jun 22 04:07:40 CEST 2011 Initiating system shutdown!
Wed Jun 22 04:07:40 CEST 2011 User logins prohibited
Wed Jun 22 04:07:41 CEST 2011 Power is back. UPS running on mains.
Wed Jun 22 04:07:41 CEST 2011 Allowing logins
Wed Jun 22 04:07:46 CEST 2011 apcupsd exiting, signal 15
Wed Jun 22 04:07:46 CEST 2011 apcupsd shutdown succeeded
Thu Jun 30 18:16:02 CEST 2011 apcupsd 3.14.7 (1 August 2009) gentoo startup succeeded
Sun Jul 03 21:16:05 CEST 2011 Power failure.
Sun Jul 03 21:16:06 CEST 2011 Battery power exhausted.
Sun Jul 03 21:16:06 CEST 2011 Initiating system shutdown!
Sun Jul 03 21:16:06 CEST 2011 User logins prohibited
Sun Jul 03 21:16:07 CEST 2011 Power is back. UPS running on mains.
Sun Jul 03 21:16:07 CEST 2011 Allowing logins
Sun Jul 03 21:16:12 CEST 2011 apcupsd exiting, signal 15
Sun Jul 03 21:16:12 CEST 2011 apcupsd shutdown succeeded
Sun Jul 03 22:12:29 CEST 2011 apcupsd 3.14.7 (1 August 2009) gentoo startup succeeded

If I check the status of the UPS using apcaccess, I notice something strange:

STATUS : ONLINE LOWBATT
LINEV : 234.0 Volts
LOADPCT : 21.0 Percent Load Capacity
BCHARGE : 100.0 Percent
TIMELEFT : 0.0 Minutes

Battery charge 100%, but still status LOWBATT and timeleft 0 min.

Any ideas about what can be wrong?

[BillP]

Hi Peter,

I am not familiar with how APCUPSD works but one thing that could potentially be happening is that the UPS might be set to a higher sensitivity which makes the UPS switch to battery power. Like the slightest change in voltage or frequency would make the UPS run on battery. If you do have a Microsoft Based operating system, we can try to download and install PowerChute Personal Edition to change these values and also see if the software would read the same values just like APCUPSD.

It is also worth to try to change the UPS communication cable if you have some spares. As well as reducing the loads to check if the runtime would increase.

[Anonymous user]

I've installed Power Chute. It says <1 min battery time, but it also says that the load is 44 W and that I can connect more equipment to my battery backup. After I did run a self test (which it passed), the battery charge dropped to 74%. Is this normal?

IIRC I got ~20 min of battery time right after I bought it less than two years ago.

[BillP]

Hi Peter,

Have you ever replaced the battery of your UPS? It shows that it passes a self-test but it also shows that it is slowly depleting itself.

[Anonymous user]

No, I haven't replaced the battery. The battery date is 2009-03-23, so I believe it should still be good.

[Anonymous user]

I contacted APC and they sent me a replacement battery. Now the unit is working again.

[BillP · Accepted solution]

Good to hear that you got it working again.