Fix nominal and load for EATON devices

[realies]

Can we please fix this? Haven't seen an improvement since the custom-case commit was reverted.

[dmacias72]

The problem with using a arbitrary power factor of .8 means that at 90% load your Eaton 5E 650I with a 650VA/360W power rating would be outputting over 100 watts more than it's rating. If you want you can use manual mode and set your watts to 520 to get the results you want. However I believe they are not accurate.

[PaulAnnekov]

FYI
I have Eaton 5E 850i:

battery.charge: 100
battery.runtime: 1240
battery.type: PbAc
device.mfr: EATON
device.model: 5E 850i
device.type: ups
driver.name: usbhid-ups
driver.parameter.pollfreq: 30
driver.parameter.pollinterval: 2
driver.parameter.port: auto
driver.version: 2.7.2
driver.version.data: MGE HID 1.33
driver.version.internal: 0.38
input.voltage: 224.0
outlet.1.status: on
outlet.desc: Main Outlet
outlet.id: 1
outlet.switchable: no
output.frequency: 50.0
output.frequency.nominal: 50
output.voltage: 224.0
output.voltage.nominal: 230
ups.beeper.status: enabled
ups.delay.shutdown: 20
ups.firmware: 03.08.0018
ups.load: 26
ups.mfr: EATON
ups.model: 5E 850i
ups.power.nominal: 850
ups.productid: ffff
ups.start.battery: yes
ups.status: OL CHRG
ups.timer.shutdown: -1
ups.vendorid: 0463

I have inserted a smart socket between load and UPS output. This smart socket can measure power load in Watts. Here are my measurements:

• when power socket shows 25-35W of load, upsc shows ups.load 13-15%
• when power socket shows 80-85W of load, upsc shows ups.load 25-28%

I can't guess any factor to transform ups.load % into proper load in Watts, because it looks like ups.load is non-linear value or depends not only on ups.power.nominal.