this battery provider implementation subscribes to a user-configurable
MQTT topic to retrieve the battery SoC value. the value is not
re-published under a different topic. there is no card created in the
web app's live view, since the SoC is already part of the totals at the
top of the live view. that is the only info this battery provider
implements.
closes#293.
relates to #581.
there are more interesting values available to display in the live view.
however, adding them made the list of values very long. this can be
mitigated by using a new column/card, which uses the available screen
space nicely on bigger screens.
* adding data age to battery data
* Add battery enabled flag
* Webapi and websocket api for Battery
* Webinterface for battery
* fixed bug due to naming inconsistencies
* cleaned up rounding
* dist update
* change typename to uppercase
* reverting to original file
