shaggy-solar/eg4battery

EG4 LifePower4 v2 → Home Assistant

Daemon that polls EG4 LifePower4 48V 100Ah v2 (Auto-Addressing) packs over RS-485 and publishes per-pack telemetry to MQTT with HA auto-discovery.

Status: live

As of 2026-04-24, bat1 is live via modbus_per_pack mode on its RS485 port, reporting all ~65 entities into HA:

lifepower4_1_pack_voltage            52.56 V     (16 cells × 3.285 V)
lifepower4_1_cell_01_voltage         3.285 V
lifepower4_1_cell_16_voltage         3.285 V
lifepower4_1_cell_voltage_delta_mv   2           (outstanding balance)
lifepower4_1_soc                     100 %
lifepower4_1_capacity_ah             100.0 Ah
lifepower4_1_temperature_01          21 °C
lifepower4_1_temperature_pcb         55 °C
... plus 14 warning bits, 14 protection bits, all 47 raw registers

bat2 and bat3 are wired but unpowered — the daemon logs one warning per unreachable pack per startup and keeps retrying silently. They'll come online automatically when the user powers them up.

Modes

Set by bus.mode in ~/.config/eg4-battery/eg4-battery.yaml:

Mode	When to use
modbus_per_pack	Default. One FTDI per pack's RS485 port. Fully decoded HA entities.
active	Legacy 7E/0D (V1 firmware only). Not used on V2 hardware.
passive	Listen-only Modbus sniff (19200). Diagnostic use.

See NOTES.md for architecture, register map, LVX6048 compatibility findings, and bring-up checklist.

What's in the box

eg4battery/
├── README.md                            ← start here
├── Install.md                           ← detailed walkthrough + mode-switch howto
├── NOTES.md                             ← architecture, register map, port matrix
├── install.sh                           ← idempotent installer (supports --dry-run)
│
├── bin/eg4-battery                      ← single-file daemon (uv PEP-723 inline deps)
│
├── config/eg4-battery.yaml.example      ← template, multiple-pack config
│
├── etc/                                 mirror of target paths (Pi side)
│   ├── udev/rules.d/99-eg4-rs485.rules
│   └── systemd/system/eg4-battery.service
│
├── homeassistant/                       ← drop into your HA config dir
│   ├── README.md                        (what goes where + retention tiers)
│   ├── recorder.yaml                    (exclude noisy / diagnostic entities)
│   ├── template_sensors.yaml            (derived: power, temp_max, cell_imbalance, stack rollups)
│   └── lovelace_overview.yaml           (3-pack stack dashboard)
│
└── tmp/                                 ad-hoc diagnostics
    ├── port-probe                       (single-cycle 9600/19200/7E probe)
    ├── eg4-snapshot                     (47-reg dump for BMS Tool cross-check)
    └── bms-tool-ref/                    (unpacked vendor BMS Tool for RE reference)

Quick start on a fresh host

cd ~/solar/eg4battery
./install.sh --dry-run          # mock cycle, prints MQTT payloads, exits

# Edit ~/.config/eg4-battery/eg4-battery.yaml:
#   - For modbus_per_pack: one 'packs:' entry per pack, each with port + address + baud
#   - mqtt.host / username / password

./install.sh                    # real deploy; auto-starts once creds are filled
journalctl -u eg4-battery.service -f

Related packages

• ../LVX6048/ — inverter-side monitoring via PI18 over USB-HID. Same MQTT broker. Between the two packages, HA sees every useful number from the stack.

Acknowledgements

• battery/eg4_lifepower.py — V1 protocol decoder adapted from Louisvdw/dbus-serialbattery. Historical; V2 firmware moved to Modbus on a different port.
• EG4 Electronics lv_host.app — the vendor BMS Tool; its Qt binary's SQLite schema and strings gave us the register-to-field mapping.