APC UPS Calibration error

I’m trying to use a Mikrotik to monitor a APC UPS.

I can view the status of the UPS (voltage, line state, etc), but when running calibration via “/system ups rtc 0” I get the following error: failure: Cannot calibrate USB ups

Why is it not possible to run calibration on a USB UPS?

Router OS version 6.37.3
APC Model number: Back-UPS RS1000G FW:868.L3 -P.D USB FW:L3 -P

Any help would be appreciated.

Thanks.

I just setup my RS1000G, and I have the same problem. I’m using an RB750Gr3 on RouterOS v6.37.4.

Model: Back-UPS RS1000G FW:868.L4 -P.D USB FW:L4 -P

[admin@MikroTik] /system ups> rtc 0
failure: Cannot calibrate USB ups

I’m going to test it now with a different UPS. I want to setup scripted runtime calibration and reports for all sites using APC backup power, to help identify reduced battery capacity and schedule battery replacement.

I received the same problem from an ES-750G.

Model: Back-UPS ES 750G FW:908.W4 .D USB FW:W4

[admin@MikroTik] /system ups> rtc 1
failure: Cannot calibrate USB ups