Powerwall integration should have energy and capacity sensors

Feature Requests
1

The Powerwall integration currently exposes the battery charge % as a sensor however the Powerwall API also returns the battery charge energy in watts and also capacity in watts.

The tesla_powerwall Python library has two methods that returns these values

powerwall.get_energy()
#=> 14807 (W)

powerwall.get_capacity()
#=> 28078 (W)

I think it might be useful to have these values returned as a sensor too.

The capacity is an interesting metric to monitor and compare over time for battery degradation.

2

Don’t forget to vote for your own request.

3

Can I also suggest temperature as a useful sensor. In the winter when the Powerwall is cold it charges slower so it’s useful to be able to monitor this.

4

If this is implemented, please use the correct units.

The energy and capacity are measured in ‘watt hours’ (Wh), not watts. The GitHub doc’s need correcting.
See https://www4.enphase.com/en-in/support/what-difference-between-watt-and-watt-hour

The Powerwall when new comes with 13,500 Wh, or 13.5 kWh of usable capacity.
From https://www.tesla.com/powerwall: “Energy Capacity 13.5 kWh”

I believe the 10 year warranty states that after 10 years, it should still have at least 70% of that capacity. So I second this RFE as a graph over the years will help to show if the Powerwall is staying within warranty or needs service from the supplier.

5

As someone with a failed powerwall this data would really help with the Tesla warranty process.
There were arguments over its capacity. Would be nice to have the history to show them.

6

System Status provides information on batteries and inverters. (nominal_full_pack_energy is useful for monitoring degradation over time

https://192.168.86.123/api/system_status

{
  "command_source": "Schedule",
  "battery_target_power": 15000,
  "battery_target_reactive_power": 0,
  "nominal_full_pack_energy": 42122,
  "nominal_energy_remaining": 34801,
  "max_power_energy_remaining": 0,
  "max_power_energy_to_be_charged": 0,
  "max_charge_power": 15000,
  "max_discharge_power": 15000,
  "max_apparent_power": 15000,