Add calibration-charge skill to fix EG4 SoC counter drift (improvement #1)

The everyday profile caps grid charging at 54V, so the bank can go weeks
without a full charge and the EG4 BMS coulomb counters drift (proven: pack 6
read 76% SoC while at the same 53.4V/3.337V-per-cell as packs reading 50-55%
— all paralleled, so physically equal charge; the spread is pure drift).

- profiles/eg4-lp4-v2-calibration.yaml: temporary profile, identical to
  canonical except stop_charge_voltage 54.0 -> 0 (Full), so grid can finish a
  full charge to the 56.4V absorption hold that re-anchors every pack to 100%.
- calibration-charge skill: guided runbook (pre-flight safety, two methods
  solar-only / grid-assist, live monitoring with cell-voltage/temp aborts,
  re-anchor verification, mandatory revert).
- REFERENCE: scoped action-policy exception (this skill alone may flip
  stop_charge, both units, user-confirmed, must revert); corrected pack-6 /
  SoC-drift notes to the verified equal-voltage-different-SoC signature.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.claude/skills/REFERENCE.md

@@ -114,9 +114,13 @@ MQTT — compute them yourself from the raw entities when working off the Pi.
   untrustworthy and use the `lifepower4_*` pack entities for any battery math; if it
   reads ~10 V right now, a powermon (or inverter) restart may clear it — worth testing.
 - **Pack 6 is an oddball**: Modbus addr `0x01` @ 115200 (packs 1–5 are `0x40` @
-  9600); ran 65 % SoC while 1–5 sat 40–44 %. Treat as a distinct member.
+  9600). It reads SoC high (76 % on 2026-06-24 vs 50–55 % on packs 1–5) — but at the
+  SAME pack_voltage (53.4 V) and cell voltage (3.337 V), so that's **counter drift,
+  not real imbalance**: all packs are paralleled and physically at the same charge.
 - **EG4 SoC never re-anchors** (drifts because packs rarely hit 100 % to reset the
-  coulomb counter). See memory `project_eg4_soc_drift_remediation`.
+  coulomb counter). Verified live via the equal-voltage/different-SoC signature above.
+  Fix = the `calibration-charge` skill (periodic full charge). See memory
+  `project_eg4_soc_drift_remediation`.
 - **RS485 daisy-chain silences slave packs** — each pack needs its own FTDI; an
   inter-pack chain demotes slaves. See memory `project_eg4_daisy_chain_silences_slaves`.
 - **No per-day inverter energy** — PI18 only gives `ET` (lifetime Wh); ED/EM/EY NAK.
@@ -143,3 +147,9 @@ MQTT — compute them yourself from the raw entities when working off the Pi.
 
 When a fix is outside the allowed set, report the finding and hand the user the
 precise command(s) to run.
+
+**Scoped exception — `calibration-charge` skill only:** that one skill may change
+exactly one setting (`stop_charge_voltage` → Full and back) via the prepared
+`eg4-lp4-v2-calibration.yaml` profile, on BOTH inverters, and ONLY after explicit
+in-session user confirmation, and it must REVERT afterward. No other skill and no
+other setting. This does not loosen the policy above for anything else.

.claude/skills/calibration-charge/SKILL.md

@@ -0,0 +1,109 @@
+---
+name: calibration-charge
+description: >-
+  Guided runbook to re-anchor the 6 EG4 LifePower4 pack SoC counters by driving a
+  full charge to absorption and verifying every pack resets to 100%. Use when pack
+  SoC readings have drifted (e.g. one pack reads much higher/lower than the others
+  while all pack voltages agree), when the user asks to "calibrate / balance / fix
+  SoC / do a full charge", or on a monthly cadence. This is the ONE skill that
+  changes inverter settings — and only the grid-charge ceiling, only on explicit
+  user confirmation, and it reverts them. Everything else is read/monitor/verify.
+---
+
+# calibration-charge
+
+Re-anchors drifted EG4 SoC counters. The BMS only resets SoC to 100% on a real
+full-charge termination (high cell voltage + low taper current); the everyday
+profile caps grid charging at 54 V, so the bank can go weeks without a full charge
+and the counters drift. This runbook guarantees one full charge, then verifies.
+
+## Action-policy exception (read this)
+Unlike the troubleshoot-* skills, this one MAY change two inverter settings — but
+ONLY `stop_charge_voltage` (54.0 → 0/Full) via the prepared calibration profile,
+applied to BOTH units, and ONLY after the user explicitly confirms in-session. You
+present the exact `flash.py` commands; the user runs them (or confirms you may). You
+own pre-flight, monitoring, verification, and the REVERT. Never change anything else.
+
+## 0. Load context
+```bash
+ROOT="$(git rev-parse --show-toplevel)"; SNAP="$ROOT/.claude/skills/lib/solar-snapshot"; HIST="$ROOT/.claude/skills/lib/ha-history"
+FLASH="$ROOT/LVX6048/lvx-flash"   # flash.py + profiles/ live here
+```
+Read `$ROOT/.claude/skills/REFERENCE.md`. The two profiles: `eg4-lp4-v2.yaml`
+(canonical/everyday) and `eg4-lp4-v2-calibration.yaml` (temporary; identical except
+`stop_charge_voltage: 0`).
+
+## 1. Pre-flight (must pass before charging)
+```bash
+"$SNAP" -w 16 -g 'lifepower4_[1-6]_(soc|pack_voltage|cell_voltage_max|cell_voltage_delta_mv|temperature_pcb|protection)' 'homeassistant/sensor/+/state'
+```
+Record and check:
+- **Capture the "before" SoC spread** — this is what we're fixing. Confirm it's *drift*
+  not real imbalance: if all 6 `pack_voltage` agree (±0.1 V) but SoC readings differ,
+  it's counter drift (the target). If voltages actually diverge, STOP — that's real
+  imbalance → troubleshoot-battery first.
+- **Temps in charge range**: every `temperature_*` between ~5 °C and 45 °C. **Never
+  charge LFP below 0 °C** (BMS should block, but verify). Abort if any pack > 45 °C.
+- **No protection bits set**; cells reasonably balanced (`cell_voltage_delta_mv` < ~50).
+- **Forecast/grid**: solar-only needs a sunny low-load day; grid-assist works anytime.
+
+## 2. Choose the method (ask the user)
+- **Solar-only (no setting change, free):** on a sunny, low-load day the bank reaches
+  bulk 56.4 V on its own (the 54 V cap only gates GRID charging, not solar). Just
+  monitor §4 and verify §5. Best when weather cooperates; no flash needed — skip §3.
+- **Grid-assist (reliable, any weather):** temporarily lift the grid-charge ceiling so
+  grid finishes the top-off. Needs the setter change in §3. Use this if it's cloudy or
+  a full charge hasn't happened in a while.
+
+## 3. Grid-assist: apply the calibration profile (USER-CONFIRMED setter change)
+Mirror to BOTH inverters (parallel cluster — mismatched settings throw fault 86).
+`flash.py apply` stops powermon for exclusive USB, so MQTT telemetry pauses briefly.
+```bash
+cd "$FLASH"
+sudo systemctl stop powermon.service powermon2.service
+./flash.py apply --device /dev/lvx6048-1 --profile profiles/eg4-lp4-v2-calibration.yaml --confirm
+./flash.py apply --device /dev/lvx6048-2 --profile profiles/eg4-lp4-v2-calibration.yaml --confirm
+./flash.py compare --device-a /dev/lvx6048-1 --device-b /dev/lvx6048-2   # must match
+sudo systemctl start powermon.service powermon2.service
+```
+Confirm via MQTT the new ceiling took (both units): `battery_recharge`/`stop_charge`
+readback reflects Full, others unchanged.
+
+## 4. Drive + monitor the charge (this is the agent's job — poll periodically)
+```bash
+"$SNAP" -w 16 -g 'lifepower4_[1-6]_(soc|pack_voltage|pack_current|cell_voltage_max|temperature_pcb)' 'homeassistant/sensor/+/state'
+"$SNAP" -w 10 -g 'lvx6048_[12]_(device_mode|mppt1_input_power|ac_output_active_power)/' 'homeassistant/sensor/+/state'
+```
+Watch for, and re-poll every ~15–30 min as it climbs:
+- `pack_voltage` rising toward ~56 V; `device_mode` should show charging/absorption.
+- **SAFETY — abort and revert (§6) if:** any `cell_voltage_max` > **3.60 V** (BMS
+  protects ~3.65; don't ride it), any pack temp > 45 °C, or any protection bit sets.
+- **Absorption/taper:** once pack voltage holds near bulk and `pack_current` tapers to
+  ~5 A/pack (≈0.05 C, < ~30 A total), the BMS will flip SoC to 100%. This hold is the
+  part that actually re-anchors — let it finish, don't cut it early.
+
+## 5. Verify the re-anchor (the whole point)
+```bash
+"$SNAP" -w 16 -g 'lifepower4_[1-6]_(soc|pack_voltage|cell_voltage_delta_mv)' 'homeassistant/sensor/+/state'
+```
+PASS = **all 6 packs read SoC 100%** (≥99) with pack voltages converged (spread
+< ~0.1 V) and cell deltas still tight. The previously-drifted pack (e.g. pack 6) now
+matching the others = counter re-anchored. Report before→after SoC spread.
+If a pack still lags, it didn't terminate — extend the hold or investigate that pack.
+
+## 6. REVERT (mandatory if you did §3 — do NOT leave the ceiling lifted)
+```bash
+cd "$FLASH"
+sudo systemctl stop powermon.service powermon2.service
+./flash.py apply --device /dev/lvx6048-1 --profile profiles/eg4-lp4-v2.yaml --confirm
+./flash.py apply --device /dev/lvx6048-2 --profile profiles/eg4-lp4-v2.yaml --confirm
+./flash.py compare --device-a /dev/lvx6048-1 --device-b /dev/lvx6048-2
+./flash.py sync-check --device-a /dev/lvx6048-1 --device-b /dev/lvx6048-2
+sudo systemctl start powermon.service powermon2.service
+```
+Confirm `stop_charge` is back to 54.0 on both units via MQTT.
+
+## 7. Record
+Note the date (for the ~monthly cadence) and before→after SoC spread. If drift returns
+fast, consider the opt-in `soc_estimator` daemon backstop (see memory
+`project_eg4_soc_drift_remediation`) as a longer-term fix.

LVX6048/lvx-flash/profiles/eg4-lp4-v2-calibration.yaml

@@ -0,0 +1,51 @@
+# LVX6048 settings profile — TEMPORARY calibration charge for the EG4 LP4 v2 bank.
+#
+# Purpose: re-anchor drifted EG4 pack SoC counters (and top-balance) by letting the
+# bank reach a FULL charge with absorption hold. The EG4 BMS resets SoC to 100% only
+# on a real full-charge termination (high cell voltage + low taper current); the
+# conservative everyday profile stops grid charging at 54.0 V (mid-knee), so on cloudy
+# / high-load stretches the bank may go weeks without a full charge and the coulomb
+# counters drift (e.g. pack 6 read 76% while physically at ~53% on 2026-06-24).
+#
+# The ONLY change vs the canonical eg4-lp4-v2.yaml is:
+#   stop_charge_voltage: 54.0  ->  0   (= "Full"; remove the grid-charge ceiling so a
+#                                        full charge can complete even without strong sun)
+# bulk_voltage stays 56.4 (the absorption target). Solar already charges past 54 V on a
+# good day; this profile just lets GRID finish the top-off when solar can't.
+#
+# USE: this is a TEMPORARY profile driven by the `calibration-charge` skill. Apply to
+# BOTH inverters, run the full charge, verify all 6 packs hit 100%, then REVERT to
+# eg4-lp4-v2.yaml. Do not leave this profile applied — it removes the everyday
+# grid-charge ceiling.
+#
+#   sudo systemctl stop powermon.service powermon2.service
+#   ./flash.py apply --device /dev/lvx6048-1 --profile profiles/eg4-lp4-v2-calibration.yaml --confirm
+#   ./flash.py apply --device /dev/lvx6048-2 --profile profiles/eg4-lp4-v2-calibration.yaml --confirm
+#   ./flash.py compare --device-a /dev/lvx6048-1 --device-b /dev/lvx6048-2
+#   sudo systemctl start powermon.service powermon2.service
+#   # ... drive + verify the charge (see calibration-charge skill) ...
+#   # REVERT when all packs read 100%:
+#   sudo systemctl stop powermon.service powermon2.service
+#   ./flash.py apply --device /dev/lvx6048-1 --profile profiles/eg4-lp4-v2.yaml --confirm
+#   ./flash.py apply --device /dev/lvx6048-2 --profile profiles/eg4-lp4-v2.yaml --confirm
+#   sudo systemctl start powermon.service powermon2.service
+
+battery_type: USER
+
+cutoff_voltage: 48.0
+stop_discharge_voltage: 48.0
+
+# 0 = Full — let grid charge all the way to bulk (the calibration lever).
+stop_charge_voltage: 0
+
+bulk_voltage: 56.4
+float_voltage: 54.0
+
+max_charging_current: 60
+max_utility_charging_current: 30
+
+output_source_priority: solar_battery_utility
+charger_priority: solar_first
+solar_power_priority: battery_load_utility_ac
+
+grid_tie: disabled