New Back-UPS ES 850G2 reporting 2% load

[NickH]

.... when drawing about 80w

This is with the apcupsd suite of programs. I am unable to perform a battery calibration as the load needs to be >=10%. What I don't understand is why the UPS is showing such a low load when the server and UPS draw a fluctuating load of about 80w at the wall. There is also a 5-port switch plugged into the UPS which draws minimal power. I have checked and only the monitor is plugged into the unprotected sockets.

Any ideas?

[Teken]

There needs to be a minimum attached load on the UPS for it to provide any reasonable value. The operating runtime, load, and efficiency (if available) are dependent on a (minimum) defined load. A battery calibration also requires a minimum of 30% attached load for the system to recalculate its operational runtime / battery capacity.

[NickH]

It is looking like the power draw is fluctuating quite quickly and if I repeatedly refresh `apcaccess` I see values up to 16%, abut as it often drops below 10% `apctest` refuses to do a calibration.

At the same time, I probably need to power down the server then power off the UPS. Then unplug the server so the UPS gets a proper baseline before plugging in the server. At that point I hope it will then pick up the correct load as it is not at the moment.

If there are any other ways to perform this reset or re-baseling, please let me know.

[Teken]

Hi,

Just to be clear there are a couple things that need to be separately addressed which is operational runtime vs displayed load (wattage).

The minimum load for your specific model UPS should be called out in the technical literature.

Minimum Load: Connect at least 150 watts of resistive load vs reactive loads and see what the system indicates. Keeping in mind the power meter inside the unit is NOT very accurate but does provide a good indicator.

Anything that is below the stated (APC Minimum) load will not be very accurate. If knowing the true wattage is important to you. I would encourage you to purchase a quality energy meter. Doing so will at the very least provide you some insight and a comparable reference. 👍

Software: You should be using APC PCPE / PCSS (Power Chute Personal Edition / Power Chute Serial Shutdown). Doing so will insure compatibility and allow you to see the metrics as accurately as possible. It will also enable you to manually initiate a battery calibration if available.

Battery Calibration: A calibration of the battery is extremely tough on the cells and impacts both the cycle life / service life. As such should only be done once a year or when the battery cartridge has been changed.

In the following procedure both require there be at (least) 30% load connected to the output of the unit. You can initiate the battery calibration via PCPE / PCSS. 

The second option is to remove AC Mains from the wall. In both cases the unit will drain the cells to a defined level of depletion. Once complete the system will recharge the battery cell during the battery calibration. In the manual procedure you’ll obviously have to reconnect the AC Mains to recharge the cells.

Once the cells are 100% charged review what the operational runtime is with no load, minimum load, 50%, 100% load. You can compare the operational runtime with the APC runtime chart for your product and see how close it is.

The APC numbers are based on new cells and a defined resistive loads. The battery calibration procedure is intended to provide the most accurate (displayed) operational runtime to the end user.

Keeping in mind the runtime is (dynamic) based on the connected loads, battery health, temperature, power quality, and environmental conditions. 

[NickH]

The whole system draws 70W-80W at the UPS input. I find it surprising that the UPS reports 2% most of the time. I can try to artificially increase the load on it but it seems odd to have to do that.

With respect to the software, as the server is a Linux server, I cannot run PCPE / PCSS which is Windows only and have to run Apcupsd which is available for many distros.

[Teken]

Please do report back what you see and observe when 150 watts is applied and what is seen by the system. 

[NickH]

I've plugged in a 100w lightbulb and the load went up to 29%. I performed a battery calibration with `apctest` and it took seconds to run. Surely this is wrong as the calibration should take the battery from 100% -> 25%?

root@pve:~# apctest


2024-06-13 20:19:37 apctest 3.14.14 (31 May 2016) debian
Checking configuration ...
sharenet.type = Network & ShareUPS Disabled
cable.type = USB Cable
mode.type = USB UPS Driver
Setting up the port ...
Doing prep_device() ...

You are using a USB cable type, so I'm entering USB test mode
Hello, this is the apcupsd Cable Test program.
This part of apctest is for testing USB UPSes.

Getting UPS capabilities...SUCCESS

Please select the function you want to perform.

1) Test k_ll UPS power
2) Perform self-test
3) Read last self-test result
4) View/Change battery date
5) View manufacturing date
6) View/Change alarm behavior
7) View/Change sensitivity
‌:smiling_face_with_sunglasses:‌ View/Change low transfer voltage
9) View/Change high transfer voltage
10) Perform battery calibration
11) Test alarm
12) View/Change self-test interval
Q) Quit

Select function number: 10

This test instructs the UPS to perform a battery calibration
operation and reports the result when the process completes.
The battery level must be at 100% and the load must be at least
10% to begin this test.

Battery level is 100% -- OK
Load level is 28% -- OK
Clearing previous self test result...CLEARED

The battery calibration should automatically end
when the battery level drops below about 25%.
This process can take minutes or hours, depending on
the size of your UPS and the load attached.

Initiating battery calibration...INITIATED

Waiting for calibration to complete...
To abort the calibration, press ENTER.

CALIBRATION COMPLETED
Result of last self test: NO TEST PERFORMED

I then tried a self-test and the test did not complete:

1) Test k_ll UPS power
2) Perform self-test
3) Read last self-test result
4) View/Change battery date
5) View manufacturing date
6) View/Change alarm behavior
7) View/Change sensitivity
‌:smiling_face_with_sunglasses:‌ View/Change low transfer voltage
9) View/Change high transfer voltage
10) Perform battery calibration
11) Test alarm
12) View/Change self-test interval
Q) Quit

Select function number: 2


This test instructs the UPS to perform a self-test
operation and reports the result when the test completes.

Clearing previous self test result...CLEARED
Initiating self test...INITIATED
Waiting for test to complete...TEST DID NOT COMPLETE

Something seems terribly wrong?

And I've put in the word k_ll as the forum rejects a post when the word is spelt with an `i` instead of the `_`.