How to change Energy units from J to kWh

[Andy_Co]

Hi,

After upgrade to 3.4 M5 Shelly EM3 change unit of Accumulated Total Power from kWh to J - how to change it ? I’m using influxdb persistence.

Thanks

[stefaanbolle]

1 Kilowatthour = 3600 Kilojoule

You can transform the item’s channel using a js-transformation
#nano /etc/openhab/transform/kWhtokJ.js
(function(i) {
var nVal= parseFloat(i) * 3600;
return nVal.toFixed(0)
})(input)

[binderth (Thomas Binder)]

see

UoM default units and consequences

I just read the release notes and took a look at the “breaking changes”. Unfortunately I am struggeling to understand the following note: Core Runtime Default units have been added for all dimensions. A state description defining the unit should be added to each item that uses a different unit. After reading this I think “state description” means this: [image] I also found this. But that is confusion me even more. I guess that is only meant for developers anyway. So what do I (as a nor…

from openHAB 3.4 onwards Number:xxx items now have a default UoM if none is given, in case of energy its Joule. You have to define your own UoM (Units of Measuerment) for all those item types, if you’re not using the defaults.

[hilbrand (Hilbrand Bouwkamp)]

There was a ‘bug’ in the milestone release where channels which had %unit% displayed in the default unit. This was most visible with energy channels that displayed in J. Best to update to the released version. That should fix this issue.

[rlkoshak (Rich Koshak)]

@binderth

You have to define your own UoM (Units of Measuerment) for all those item types, if you’re not using the defaults.

Just for completeness, to define your own UoM, set the Item’s State Description Pattern with the unit desired.

[Andy_Co]

Upgrade helped. Thanks. No need to define own UoM in this case.