Charging amps as a numeric value of another entity

[spinecho31]

First and foremost I'm still a newbie on Home Assistant

I'm trying to set an automation where the charging_amps (A) = "Excess solar power"(W) / Current (V)

I can create a sensor.optimum_charging_amps but the problem is that when setting an automation I am not allowed to use a numeric value of another entity and I have to use a fixed value for the Amps instead

How can I get around this?

[fhteagle]

I use an "input_number" helper (not sensor) for things I want to calculate and store, and maybe set on the car later (depending on other bits of logic).

So, my suggestion is to create an input_helper called something like "solar_amps_avail". Set up an automation to calculate solar amps avail, which would be triggered either by time interval or when your solar equipment sensors update, and assign the result to input_number.solar_amps_avail. Then, in the same or a separate automation, set number.charging_amps (the one that gets pushed to the car) equal to input_number.solar_amps_avail.

The YAML for the assignment automation action might look something like:

service: number.set_value
data:
  value: >-
    {{ [[(states('input_number.solar_amps_avail')|round(0), 1]|max, 16]|min |round(0) }}
target:
  entity_id: number.charging_amps
enabled: true

The |max and |min are just to trap the value between a sane lowest and highest value (between 1 and 16 in the above example), and the |round(0) forces the result/assignment to the car to be the nearest whole integer. If you always wanted to round down, you could use |int instead of |round(0).

[purcell-lab]

You can provide a template value via a script:

alias: Tesla Solar
sequence:
  - service: tesla_custom.api
    data:
      command: CHARGING_AMPS
      parameters:
        path_vars:
          vehicle_id: "{{ state_attr('binary_sensor.online', 'id') }}"
        charging_amps: >-
          {{
          (states('sensor.excess_solar_charging_amps')|float(0))|int(0)
          }}
mode: single

and call this script via an automation: