SmartChargeTesla

Automatically manages a Tesla Powerwall during EON Next Kraken EV dispatch windows, so when you charge your electric vehicle on the cheapest possible rate during a Smart dispatch the Powerwall charges at the same time.

Designed for the EON Next Drive Smart tariff (formerly Next Drive v5.1), which offers off-schedule cheap-rate windows dispatched via the Kraken SmartFlex platform. Works alongside a myenergi Zappi charger, which is used to confirm that the EV is actually drawing power before activating Powerwall protection.

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How it works

EON Next Kraken API
        │  polls every 60 s for planned dispatch windows
        ▼
  SQLite database  ◄─────────────────────────────────────────────────┐
        │                                                             │
        ▼                                                             │
  dispatch_action_loop (every 60 s)                                  │
        │                                                             │
        ├─ Dispatch window active?                                    │
        │   └─ YES: check myenergi Zappi                             │
        │       ├─ Zappi charging? → Powerwall BACKUP 100%           │
        │       │   └─ Dispatch or Zappi ends                        │
        │       │       → revert just before 30min slot ends         │
        │       └─ Zappi idle → no action (BACKUP not activated)     │
        │                                                             │
        └─ Google Calendar invite sent when charging confirmed ───────┘

Powerwall modes used:

Situation	Mode	Reserve
EV charging during dispatch window	BACKUP	100%
Outside dispatch window / EV idle	TIME_BASED_CONTROL	configurable (default 20%)
00:00–06:00 UK (cheap rate hours)	no change	—

The service also:

• Prunes stale dispatch records when Kraken withdraws or reschedules windows
• Extends BACKUP by 29 minutes if the Zappi is still charging when a window ends
• Sends and updates Google Calendar invites as dispatch windows are confirmed, rescheduled, or completed
• Performs a midnight reset to TIME_BASED_CONTROL so the cheap overnight rate (00:00–06:00) is never blocked

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Hardware requirements

Component	Notes
Tesla Powerwall 2 or 3	Local gateway or cloud access
myenergi Zappi	Any generation; hub required for API access
EON Next Drive Smart tariff	Kraken SmartFlex dispatch service must be enrolled
Raspberry Pi (or similar)	Runs continuously; Pi 3/4/5 and Pi Zero 2W all work

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Prerequisites

• Python 3.11 or later
• EON Next account enrolled in Drive Smart / KrakenFlex EV dispatch
• myenergi hub connected to the internet
• Tesla account (free owner API — no Fleet API developer account needed)
• Gmail account with an App Password for optional calendar invites

---

Installation

git clone https://github.com/YOUR_USERNAME/SmartChargeTesla.git
cd SmartChargeTesla
pip install -r requirements.txt

Copy the example config and fill in your credentials:

cp config.example.yaml config.yaml
nano config.yaml

---

Configuration

See config.example.yaml for a fully annotated template.

Required sections

EON Next

eon_next:
  email: "you@example.com"
  password: "your-eon-password"
  import_account: "A-XXXXXXXX"   # from EON Next app or portal

Your import account number is on your EON Next bill or in the app under Account → Electricity → Account number.

myenergi Zappi

myenergi:
  hub_serial: "12345678"   # Hub serial (starts with 10 or 11)
  api_key: "abcdef12"      # From myenergi app: Settings → myenergi hub → Advanced

Tesla Powerwall

tesla:
  account_email: "you@tesla.com"
  account_password: "your-tesla-password"

One-time authentication step — run this interactively before starting the service (it opens a browser for Tesla SSO):

python3 -c "
import pypowerwall
pypowerwall.Powerwall('', password='YOUR_PASSWORD', email='YOUR_EMAIL',
                      cloudmode=True, authpath='.')
"

This caches the auth token in .pypowerwall.json. The service then runs unattended.

Optional: Google Calendar invites

Requires a Gmail App Password (not your account password): Google Account → Security → 2-Step Verification → App passwords

gcal:
  smtp_user: "sender@gmail.com"
  smtp_pass: "xxxx xxxx xxxx xxxx"   # 16-char app password
  invite_to: "your-calendar@gmail.com"
  cheap_rate_pence: 6.19
  standard_rate_pence: 26.073

When the Zappi starts charging in a dispatch window, a calendar event is sent showing the window start/end time and estimated kWh. The event is updated if the window changes and trimmed to actual end time when the Zappi stops.

Control settings

control:
  default_reserve_pct: 20   # Battery % floor when not in BACKUP mode

---

Running manually

python run.py

Or with a custom config path:

python run.py --config /path/to/config.yaml

---

Running as a systemd service

Edit smartcharge.service and update User and WorkingDirectory to match your system:

sudo cp smartcharge.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable --now smartcharge

Check logs:

journalctl -u smartcharge -f

---

Database

Dispatch windows are stored in a local SQLite database at data/smartcharge.db. The database is created automatically on first run.

Schema:

CREATE TABLE dispatches (
    start TEXT,          -- UTC ISO datetime
    end TEXT,            -- UTC ISO datetime
    delta_kwh REAL,      -- expected energy (negative = import)
    type TEXT,           -- 'SMART_FLEX' or NULL for completed
    source TEXT,
    location TEXT,
    gcal_event_id TEXT,  -- calendar event UID
    gcal_sequence INT,
    fetched_at TEXT,
    UNIQUE(start, end)
);

---

Project structure

SmartChargeTesla/
├── run.py                     Entry point
├── config.example.yaml        Configuration template
├── requirements.txt
├── smartcharge.service        systemd unit file
├── smartcharge/
│   ├── service.py             dispatch_loop + dispatch_action_loop
│   ├── apis/
│   │   ├── kraken.py          EON Next Kraken GraphQL client (dispatch queries)
│   │   ├── myenergi.py        myenergi Zappi charging-status client
│   │   └── gcal.py            Google Calendar iCalendar invite sender
│   └── db/
│       ├── schema.py          SQLite schema and migrations
│       └── store.py           DispatchStore CRUD helpers
└── data/                      SQLite database (gitignored)

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Dependencies and credits

Library	Author	Purpose	Licence
pypowerwall	Jason Cox	Tesla Powerwall cloud API — mode and reserve control	MIT
tesla_powerwall	jrester	Local gateway API; source of Powerwall operation mode values ("autonomous", "backup") used in this project	MIT
pymyenergi	cjne	myenergi hub API client — Zappi charging status	MIT
requests	Kenneth Reitz et al.	HTTP client for Kraken GraphQL calls	Apache 2.0
PyYAML	Kirill Simonov	Configuration file parsing	MIT
aiohttp	aio-libs	Async HTTP (required by pymyenergi)	Apache 2.0
httpx	Encode	Async HTTP (required by pymyenergi batch fetch)	BSD

Also useful

TeslaPy by Tim Dorssers is not a dependency of this project but is a convenient way to generate the Tesla OAuth refresh token needed by pypowerwall if you prefer not to use the interactive browser login:

pip install teslapy
python3 -c "import teslapy; t = teslapy.Tesla('your@email.com'); t.fetch_token()"

API notices

The EON Next Kraken GraphQL API is an unofficial, undocumented interface to the same Kraken backend used by the EON Next mobile app. No affiliation with EON Next or Kraken Technologies is implied.

The pypowerwall and tesla_powerwall libraries use Tesla's free owner API (not the paid Fleet API). No Tesla developer account is required. Tesla, Powerwall, and related marks are trademarks of Tesla, Inc.

myenergi and Zappi are trademarks of myenergi Ltd.

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Licence

MIT — see LICENSE.