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Battery System Setup

bolagnaise edited this page Apr 21, 2026 · 44 revisions

Battery System Setup

Tesla Powerwall

Don't want to run Home Assistant? PowerSync Cloud is a fully hosted alternative ($4.99/month) for Tesla Powerwall users on Amber, GloBird, or Energy Locals. No local server needed — sign in with Tesla, pick your retailer, and PowerSync handles negative-price protection and AEMO spike export automatically. Includes iOS/Android apps and a real-time web dashboard.

PowerSync supports three methods for accessing your Tesla Powerwall via the Home Assistant integration. Choose one — you don't need all three.

Option 1: PowerSync (Recommended — Free)

The easiest option. PowerSync is a registered Tesla Fleet API partner — when you sign in, Tesla authorizes PowerSync.cc to read your Powerwall data and send commands on your behalf. We never see your Tesla password.

Pros
Free Tesla doesn't charge for energy product reads or commands
30-second setup Click a link, sign in with Tesla, paste a token
No Tesla developer account We're already a registered Fleet API partner
No HA integration prerequisite Works without tesla_fleet installed
Works in any region NA, EU, APAC, MEA — region detected automatically

Setup:

  1. In Home Assistant, add the PowerSync integration. When asked which Tesla provider to use, choose PowerSync (recommended).
  2. Open this URL in any browser: https://api.powersync.cc/auth/start
  3. Sign in with your Tesla account (Tesla shows a consent screen — approve the energy product scopes)
  4. You'll get a token starting with psync_ — copy it
  5. Paste it back into the PowerSync setup form

That's it. Tesla never sees Home Assistant; PowerSync.cc never sees your Tesla password. The token is the only thing that links your HA install to your Powerwall, and you can revoke it any time at https://accounts.tesla.com/account-settings/security or by removing the integration.

If your token gets invalidated for any reason (revoked, expired, etc.), Home Assistant will automatically prompt you to re-authenticate via the same flow.

Option 2: Tesla Fleet API (Free)

Direct access via your own Tesla developer app. Free but requires you to do the developer registration and OAuth setup yourself.

Setup:

  1. Install the official Tesla Fleet integration in Home Assistant
    • Settings > Devices & Services > Add Integration > "Tesla Fleet"
    • Follow the login flow (requires your own Tesla developer app)
  2. PowerSync automatically detects your Tesla Fleet credentials
  3. When PowerSync asks which provider to use, select Tesla Fleet API

Option 3: Teslemetry (~$4/month)

Third-party paid proxy. Use this if you prefer a managed service or already have a Teslemetry subscription.

Setup:

  1. Sign up at https://teslemetry.com
  2. Connect your Tesla account
  3. Copy your API key
  4. Choose Teslemetry in the PowerSync setup and paste your API key

FoxESS

Supports H1, H3, H3-Pro, H3 Smart, and KH model families. All control is done locally — no cloud API required for battery control.

OEM rebrands using identical hardware are also supported — the model family is detected automatically during setup.

Supported Models

Model Family Type OEM Rebrands
H1 Single Phase AIO-H1, a-TroniX AX
H3 Three Phase AIO-H3, Kuara H3, Sonnenkraft SK-HWR, 1KOMMA5
H3-Pro Three Phase (Higher Power)
H3 Smart Three Phase (Native WiFi)
KH Single Phase Hybrid

Rebrands: If your inverter is an OEM rebrand (e.g., Kuara, Sonnenkraft, 1KOMMA5), just connect it like any other FoxESS unit. PowerSync identifies the model family automatically — no special configuration needed.

Connection Options

Modbus TCP (Recommended for H3 Smart)

  • Port: 502 (default)
  • Slave ID: 247 (default)
  • For H3 Smart: Connect directly to the inverter's IP address — no external adapter needed

RS485 Serial

  • Baud rate: 9600 (default)
  • Slave ID: 247 (default)
  • Requires an RS485 adapter (USB or network gateway like Elfin EW11)

H3 Smart Setup

The H3 Smart has a built-in WiFi connection. No external adapter is needed.

  1. Find the inverter's IP address — it appears as "espressif" on your network
  2. Ensure firmware is up to date — required for a stable connection
  3. Use default settings — Port 502, Slave ID 247
  4. PowerSync will auto-detect the model as H3 Smart during setup

Troubleshooting: If the connection test fails:

  • Check your router for a device named "espressif" to find the correct IP
  • Update inverter firmware to the latest version
  • Verify port 502 is not blocked by your network

FoxESS Cloud (Optional)

A FoxESS Cloud API key allows PowerSync to sync electricity prices as time-based schedules on your inverter (up to 8 periods per day). This is not required for battery control.

Getting your API key:

  1. Log in to foxesscloud.com
  2. Go to User Profile > API Management
  3. Generate a new API key
  4. Enter the API key and your device serial number during PowerSync setup

Note: When Smart Optimization is enabled, cloud schedule sync is automatically skipped — the optimizer controls the inverter directly, and uploading schedules to the cloud would conflict.

Work Modes

Mode Description
Self Use Normal self-consumption — battery powers home, charges from solar
Feed-in First Prioritises exporting to grid
Backup Reserves battery for backup power
Peak Shaving Reduces grid import during peak periods (H3-Pro/Smart only)

Force Charge/Discharge (v2.5.0+)

Precise power control for charging or discharging the battery on demand. The power level is read from the inverter's own configured maximum — not a fixed cap.

Feature Description
Force Charge Charges battery from grid at a configurable power level
Force Discharge Discharges battery to grid
Max power Read automatically from the inverter

Sigenergy

Full support for Sigenergy hybrid inverters with integrated battery storage.

Features

  • Tariff Sync via Cloud API — Uploads pricing to Sigenergy Cloud using 30-minute time-of-use format
  • Real-Time Energy Data — Reads solar, battery, grid power and state of charge locally
  • DC Solar Curtailment — Stops grid export during negative prices while still powering your home

Connection Requirements

Connection Purpose Required
Cloud API Tariff sync to Sigenergy Yes
Local (Modbus TCP) Real-time energy data + DC curtailment Yes

Important: Local Modbus access must be enabled on your Sigenergy inverter before PowerSync can connect. This is typically configured by your installer via the SigenStor app or installer portal.

Device ID Note: If you have an AC Charger installed, it uses Device ID 1 by default. The inverter must be set to a higher ID (e.g., 2).

Getting Cloud API Credentials

Credential Description Where to Find
Email Your Sigenergy account email Your login email
Password Your Sigenergy account password Your normal password
Device ID Optional — usually not needed Leave blank
Station ID Your Sigenergy station identifier SigenAI app or browser dev tools

Device ID (optional):

Leave this field blank — Sigenergy no longer requires a Device ID for authentication. If authentication fails without it, you can find it by:

  1. Go to https://web-aus.sigencloud.com/ in your browser (don't log in yet)
  2. Open Developer Tools (F12) > Network tab > filter by Fetch/XHR > check "Preserve log"
  3. Log in normally
  4. Find the token POST request > Payload tab > look for userDeviceId (13 digits)

Getting Station ID:

  • Ask SigenAI in the app: "Tell me my StationID"
  • Or find it in the browser dev tools network requests

Force Charge/Discharge (v2.5.0+)

Feature Description
Force Charge Charges battery from grid at a configurable power level
Force Discharge Discharges battery to grid
Restore Normal Returns to normal self-consumption and restores backup reserve
Backup Reserve Saved before force modes and restored automatically

Sigenergy Configuration

  1. Select Sigenergy as your battery system
  2. Enter Cloud credentials (email, password)
  3. Select your station from the list
  4. Enter your inverter's IP address
  5. Optionally enable DC solar curtailment

GoodWe

Full support for GoodWe hybrid inverters. Local connection only — no cloud API required.

Features

  • Auto-Detection — Model family is automatically identified during setup
  • Force Charge/Discharge — Charges or discharges the battery on demand
  • Backup Reserve — Set minimum state of charge
  • Grid Export Limit — Configurable export power limit
  • Battery Health — State of health read from inverter

Supported Models

Series Type Battery Control
ET Three Phase Hybrid Full support
EH Three Phase Hybrid Full support
BT Three Phase Hybrid Full support
BH Three Phase Hybrid Full support
ES Single Phase Hybrid Full support
EM Single Phase Hybrid Full support
BP Single Phase Hybrid Full support
DT/MS/XS Grid-only (no battery) Not supported

Connection Options

UDP via WiFi Dongle (Default)

  • Port: 8899
  • Works with most GoodWe inverters out of the box

TCP via LAN Dongle

  • Port: 502
  • Requires a GoodWe LAN dongle (WLA0000-01-00P V2.0)
  • More reliable for installations with poor WiFi

TCP via Modbus Gateway (EMS Mode)

  • Some installations connect GoodWe through a third-party Modbus TCP gateway
  • In this setup the inverter's UDP port 8899 is unreachable, so operation mode registers cannot be written directly
  • PowerSync works around this by relaying force charge/discharge commands through the GoodWe Home Assistant integration's EMS entities, which use registers that accept TCP writes
  • See Modbus TCP Gateway Setup below

GoodWe Setup

  1. Find the inverter's IP address — check your router's device list for the WiFi or LAN dongle
  2. Select GoodWe as your battery system during PowerSync setup
  3. Enter the inverter's IP address
  4. Select the protocol (UDP or TCP) matching your dongle type
  5. The port defaults automatically (8899 for UDP, 502 for TCP)
  6. PowerSync tests the connection and auto-detects your inverter model

Note: If setup reports "no battery support", your inverter is a grid-only model (DT/MS/XS series) which does not have battery control capabilities.

Modbus TCP Gateway Setup

If your GoodWe inverter is connected via a Modbus TCP gateway (rather than a direct WiFi/LAN dongle), force charge and force discharge require an extra configuration step. GoodWe's operation mode registers only accept writes over the proprietary UDP protocol on port 8899 — TCP writes are silently ignored.

Prerequisites:

  • The GoodWe Home Assistant integration must be installed and working
  • This integration must be providing select.<prefix>_ems_mode and number.<prefix>_ems_power_limit entities (where <prefix> is typically goodwe)

Steps:

  1. Go to Settings → Devices & Services → PowerSync → Configure
  2. Open GoodWe Connection Settings
  3. Set EMS Entity Prefix to the entity prefix used by the GoodWe integration — typically goodwe
  4. Save

PowerSync will now route force charge, force discharge, and normal operation commands through the EMS mode entities instead of writing directly to operation mode registers. EMS mode options used: buy_power (force charge), sell_power (force discharge), auto (normal/idle).

Operation Modes

Mode Description
General / Auto Normal self-consumption operation
ECO Charge / Buy Power Force charge from grid
ECO Discharge / Sell Power Force discharge to grid

Backup Reserve

GoodWe controls backup reserve using depth of discharge (how deeply the battery is allowed to deplete). PowerSync converts automatically:

  • Setting backup reserve to 20% → battery allowed to deplete to 20%
  • Setting backup reserve to 100% → battery kept fully charged (full backup)
  • Maximum depletion is capped at 89% (minimum 11% always reserved)

Sungrow SH-series

Full support for Sungrow SH-series hybrid inverters via direct local connection. No cloud API required.

Features

  • Direct Local Control — All control via your local network
  • Force Charge/Discharge — Manual or automatic battery control
  • Rate Limiting — Set maximum charge and discharge rates (kW)
  • Export Limit Control — Limit grid export power
  • Backup Reserve — Configure minimum state of charge for backup power
  • Battery Health Monitoring — Read state of health directly from the battery
  • AEMO Spike Auto-Discharge — Automatic VPP participation for Globird users

Supported Models

Series Type Battery Control
SH-series Hybrid Inverter Full support
SG-series String Inverter AC curtailment only (no battery)

Connection Settings

Setting Default
Port 502
Slave ID 1

Dual Inverter Setup (Optional)

If you have two Sungrow SH inverters — for example, a grid-facing primary and a secondary on the primary's backup port — PowerSync can manage both as a single combined system.

How it works:

  • During initial setup, after configuring the primary inverter you'll be prompted to optionally add a second inverter's IP address
  • Both inverters are polled independently and their data is combined into a single view
  • Solar, battery power, and load are summed across both inverters
  • Grid power uses the primary inverter only (it's the grid-facing unit)
  • State of charge is capacity-weighted across both inverters
  • Commands (force charge, force discharge, restore) are sent to both inverters simultaneously
  • Charge/discharge power is split proportionally — the emptier battery gets more charging power, the fuller battery gets more discharging power, and larger batteries get a proportionally larger share

Battery capacity weights:

If your two inverters have different-sized battery stacks, configure the capacity of each so that state-of-charge averaging and power splitting are accurate. For example, if your primary has 51.2 kWh and your secondary has 102.4 kWh:

Setting Value
Primary Battery Capacity 51.2
Secondary Battery Capacity 102.4

With these settings:

  • SOC averaging is capacity-weighted. If the 51.2 kWh stack is at 80% and the 102.4 kWh stack is at 40%, the combined SOC is 53.3% — not the naive 60% average
  • Power splitting accounts for both SOC and capacity — the larger stack receives a proportionally larger share

The default capacity is 25.6 kWh for both inverters. If your battery stacks are identical, you can leave the defaults — the ratio is what matters, not the absolute values.

Setup:

  1. Configure your primary (grid-facing) Sungrow inverter as normal
  2. On the "Secondary Sungrow Inverter" step, enter the IP of your second inverter
  3. PowerSync tests the connection and stores both configurations
  4. To add/remove a secondary later, go to Settings > Devices & Services > PowerSync > Configure

Grid-forming inverter SOC cap:

In an off-grid scenario, the primary inverter needs headroom in its battery to absorb excess output from the secondary. The Primary Inverter Max SOC (%) setting caps the primary inverter's maximum charge level — for example, setting it to 90% reserves 10% buffer capacity. Set to 100% (default) to disable.

Safety features:

  • If the secondary inverter fails to connect on startup, PowerSync falls back to single-inverter mode automatically
  • Each inverter is polled independently — a temporary connection failure on one doesn't block the other
  • Removing the secondary IP in the options flow cleanly removes all secondary config

Solax

Support for Solax hybrid inverters via direct local connection. Covers all generations (GEN2 through GEN6).

Connection Options

Method Description
Modbus TCP (Standalone) Direct connection to the inverter. No additional HA integration required.
HA Entity Fallback Uses entities from the homeassistant-solax-modbus integration

Features

  • AC-Coupled Inverter Curtailment — During negative prices, export is limited. When prices recover, the original export limit is restored.
  • Load-Following Curtailment — When home load data is available, curtailment tracks actual consumption to allow solar self-use while blocking grid export.

Solax Configuration

  1. Select Solax as your battery system or AC inverter
  2. Enter the inverter's IP address and port (default: 502)
  3. If using HA entity fallback, select the appropriate entities from the Solax Modbus integration

AlphaESS

Support for AlphaESS SMILE and Storion hybrid inverter-battery systems via local connection, with optional Cloud API fallback when the local connection is unreachable.

Supported Models

  • SMILE5, SMILE-Hi5, SMILE-Hi10 (residential)
  • SMILE-B3, SMILE-T10, SMILE-G3
  • Storion-T30

Single-phase and three-phase variants are both supported.

Prerequisites

  • Ethernet cable between your AlphaESS inverter and your local network. The inverter accepts only one active local connection at a time.
  • Local control enabled on the inverter (usually default; check with your installer if unsure).
  • Optional: an AlphaESS Open API App ID + App Secret from open.alphaess.com for cloud fallback.

Connection Settings

Setting Value
Port 502
Slave ID 85 — AlphaESS factory default. Not 1 or 247 like other brands.

Features

  • Smart Optimization — PowerSync's built-in optimizer writes charge/discharge plans every 5 minutes based on price forecasts.
  • Force charge / discharge / release — Standard power_sync.force_charge, force_discharge, and restore_normal services work for AlphaESS.
  • DC Solar Curtailment — When feed-in price drops below 1 c/kWh, PowerSync blocks grid export. Solar keeps powering the house and charging the battery.
  • Battery Health — State of charge, state of health, rated capacity, and current limits are exposed as sensors.
  • Cloud Fallback — If the local connection goes unreachable, PowerSync polls AlphaESS's cloud API for data. Cloud-based control is coarser than local.

AlphaESS Configuration

  1. Select AlphaESS as your battery system during PowerSync setup.
  2. Enter the inverter's host/IP, port (default 502), and slave ID (default 85).
  3. Optionally configure an export safety cap (kW) to limit grid export during force-discharge operations.
  4. On the next step, optionally enter Open API App ID + App Secret + serial number for cloud fallback. Leave blank to use local connection only.

Single connection limit: AlphaESS firmware allows only one active local connection at a time. Don't run other AlphaESS integrations on the same inverter in parallel.

Status

AlphaESS support was introduced in PowerSync 2.12.47 and validated end-to-end against a live SMILE system. Report any issues on Discord.


Sungrow with Globird VPP

Globird's VPP program pays premium rates during AEMO price spikes ($3000/MWh or above). PowerSync can automatically participate:

  1. Enable AEMO Spike Auto-Discharge in the mobile app Controls screen
  2. Select your NEM region (NSW1, VIC1, QLD1, SA1, TAS1)
  3. When AEMO prices hit $3000/MWh, PowerSync automatically forces battery discharge
  4. When the spike ends, battery returns to normal operation
  5. Push notifications are sent for both spike start and end

Tip: If you also have a separate AC-coupled solar inverter, configure it in the AC Inverter Curtailment section. PowerSync will warn you if your Sungrow battery and AC inverter are configured with conflicting settings.

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