---
name: power-usage
description: >-
  Analyze where the power is going across the install — load vs PV generation vs
  grid vs battery flow, plus EVSE charging sessions. Use when the user asks "why is
  my battery draining / how much am I using / where are the watts going / is the car
  charging / what's my solar production / power consumption", or wants an energy
  balance or breakdown. Read-only; this skill measures and explains, it does not
  change anything.
---

# power-usage

## 0. Load context
Shell cwd is the repo root; anchor paths there:
```bash
ROOT="$(git rev-parse --show-toplevel)"; SNAP="$ROOT/.claude/skills/lib/solar-snapshot"
```
Read `$ROOT/.claude/skills/REFERENCE.md` for entity names. Key sign conventions: pack
`pack_current` is signed (**+ = charging, − = discharging**); inverter
`mppt*_input_power` is PV in (W); `ac_output_active_power` is load out (W).

## 1. Instantaneous energy balance
```bash
# Generation (PV) + load, per inverter:
"$SNAP" -w 10 -g 'lvx6048_[12]_(mppt1_input_power|mppt2_input_power|ac_output_active_power|grid_voltage|device_mode)/' 'homeassistant/sensor/+/state'
# Battery flow, per pack (sum the pack_power = V×I yourself):
"$SNAP" -w 16 -g 'lifepower4_[1-6]_(pack_voltage|pack_current|soc)/' 'homeassistant/sensor/+/state'
# EV charger:
"$SNAP" -w 8 'openevse/status' 'openevse/power' 'openevse/amp' 'openevse/voltage' 'openevse/session_energy'
```
Then state the balance in words:
- **PV in** = sum of all `mppt*_input_power`.
- **Battery** = sum of (pack_voltage × pack_current) over 6 packs. Negative total =
  discharging (load exceeds PV+grid); positive = charging.
- **Load out** = sum of inverter `ac_output_active_power`.
- **EVSE** = `openevse/power` — and the EVSE load is a *subset* of total load, so a
  draining battery with the car plugged usually explains itself here.
- **Grid**: `device_mode` Bypass/Line means grid is carrying/supplementing; Battery
  mode means running off the bank. The LVX6048 has no clean grid-power entity, so
  infer grid = load − PV − battery_discharge.

Sanity: PV + grid + battery_discharge ≈ load (within metering noise). A big residual
means one feed is mis-reported — note it (e.g. the known `lvx6048_1_battery_voltage`
~10 V glitch will corrupt any pack-power math that uses the *inverter's* battery
reading; always use the **pack** entities for battery flow).

## 2. "Why is the battery draining?"
Walk the chain: is PV low (night/shade/§5 of troubleshoot-inverter dead string)? Is
load high (check `ac_output_active_power` and EVSE `power`)? Is the inverter in
Battery mode instead of using grid (`device_mode`)? Pin the drain on the largest
negative contributor and say which.

## 3. EVSE sessions
```bash
"$SNAP" -w 10 'openevse/status' 'openevse/state' 'openevse/session_energy' 'openevse/total_energy' 'openevse/vehicle' 'openevse/pilot' 'openevse/max_current'
```
- `status` active = charging; sleeping/disabled = not drawing. `vehicle` = plugged.
- `session_energy` (Wh) this plug-in; `pilot`/`max_current` = the current cap the
  EVSE is signalling. Idle EVSE publishes little — a short empty capture is normal.
- For history/trends (daily kWh, past sessions), the data lives in **Home Assistant's
  recorder**, not on MQTT — direct the user to the HA Energy dashboard /
  `sensor.openevse_total_day|week|month`. PI18 has no per-day inverter energy
  (memory `project_lvx6048_no_daily_energy_query`); only `ET` lifetime Wh exists.

## 4. Report
Give the live balance (PV / load / battery / grid / EVSE, with numbers and signs),
the headline ("you're pulling X W from the bank because load Y W > PV Z W, car is
taking W W"), and point at HA recorder for anything historical. This skill never
changes settings — if the answer is "shift charging to solar hours" etc., suggest it
as advice, don't actuate.