33% Load => TIMELEFT 6 minutes, 31% Load => TIMELEFT 26 minutes !!!

[rems_apc]

This was originally posted on APC forums on 1/31/2011

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Hi list,

we have DELL Precision T5500 and one 24 inch monitor connected to a Back-UPS RS 800.
We are running openSUSE 11.3 and apcuspd.

apcaccess shows
LOADPCT : 31.0 Percent Load Capacity
BCHARGE : 100.0 Percent
TIMELEFT : 26.4 Minutes

We also have a 2nd DELL Precision T5500 and another 24 inch monitor connected to another Back-UPS RS 800.
This one shows
LOADPCT : 33.0 Percent Load Capacity
BCHARGE : 100.0 Percent
TIMELEFT : 6.6 Minutes

I must say that the first Back-UPS RS 800 arrived one week ago, and the 2nd one is 3 years old, but we already changed the battery to a new one about 6 months ago.
Why are the TIMELEFT values that different?

Could it have something to do with the different firmwares?
New UPS: SERIALNO : 5B1020T14549 , FIRMWARE : 9.o5 .I USB FW:o5
Old UPS (with new battery) : SERIALNO : QB0711333038 , FIRMWARE : 9.o2 .I USB FW:o2

Many thanks for any ideas and help,

Richard

[BillP]

This reply was originally posted by Jonathan on APC forums on 1/31/2011

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Have you tried doing manual runtime calibration on the second unit? In order to do manual runtime calibration, you can follow the steps below.

1. Battery must be at 100% capacity when the Runtime Calibration is initiated/started.
2. The UPS must have at least a 30% load on it during the calibration.
3. The load cannot fluctuate more than +/- 5% during the calibration.
4. The battery must be discharged to at least 25% capacity (it is best to allow the UPS to shut off due to a discharged battery).

In addition to the abovce conditions, any UPS monitoring/shutdown software should be stopped from running in the background, and the serial/USB cable should be detached from the UPS. This is necessary in order to prevent the software from shutting down the server/UPS due to an on-battery or low-battery condition.

[rems_apc]

This was originally posted on APC forums on 1/31/2011

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Thanks for your reply. I tried it, but at the moment I removed the power plug from the wall the Back-UPS gave an overload and switched off !
The load at that moment was at 42% .
I recently learned that our Back-UPS RS 800 (we have 4 of them) are not working with our DELL Workstations with active PFC power supplies ... !@%!@%!$
and that we will have to change to the bigger 3 times more expensive ones ...

apcaccess still shows 6.9 minutes TIMELEFT, but it really is 0 seconds with the active PFC power supplies !@#%!@%$!@$!@$!
I am kind of pi.... off right now.
Before selling these UPS APC should put a BIG RED WARNING about active PFC power supplies !!!

Richard

[BillP · Accepted solution]

This reply was originally posted by Jonathan on APC forums on 1/31/2011

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I apologize for what has happened. We do have an APC Knowledge Base about PFC, here is the link > http://nam-en.apc.com/app/answers/detail/a_id/8883/kw/pfc. You can trade in as well your BackUPS and get a SmartUPS on a discounted price.