access to more accurate UPS voltage via API or snmp?

RouterOS Scripting
1

It seems only the integer UPS voltage is available via SNMP:

zabbix:~ # snmpget 10.10.5.10 SNMPv2-SMI::mib-2.33.1.2.5.0 -v 2c -c public
SNMPv2-SMI::mib-2.33.1.2.5.0 = INTEGER: 13

And not at all via the API or CLI:

<<< /system/ups/print
<<<
>>> !re
>>> =.id=*1
>>> =name=ups1
>>> =port=usbhid1
>>> =offline-time=4w2d
>>> =min-runtime=never
>>> =alarm-setting=immediate
>>> =model=Back-UPS ES 600G FW:905.W1 .D USB FW:W1
>>> =serial=XXXXXXXXX
>>> =manufacture-date=2014-11-06
>>> =load=21
>>> =on-line=true
>>> =nominal-battery-voltage=12
>>> =invalid=false
>>> =disabled=false
>>>
>>> !done
>>>

But is available in winbox:

And via web config:




Does anyone have info on how I can access the more accurate voltage? There is a large difference in charge level between 12.99 and 12.00 volts that would be nice to monitor.

Thanks,
Daniel