Privacy Policy

Overview

This app lets Tesla Powerwall owners monitor and control their home battery system using Tesla's official Fleet API. Your privacy matters. This policy explains exactly what data we collect, why, where it lives, and what rights you have over it.

What Data We Collect

We collect only what is necessary to connect to your Powerwall:

• Tesla OAuth tokens – an access token and a refresh token, issued by Tesla when you sign in with your Tesla account. These allow the app to call the Tesla Fleet API on your behalf.
• Email address – fetched from Tesla's userinfo endpoint after you authenticate. Used solely to identify your account within the app.
• Approximate location – only if you choose to use sunrise or sunset automations. Sunrise and sunset times depend on where your home is, and Tesla's API does not provide your site's coordinates, so we ask you for them. You can let the app read your device's approximate position, or type the coordinates in yourself.
  We request coarse location only (roughly 3 km accuracy), read it once when you set it up, and store it rounded to two decimal places – about a kilometre. We never request background or precise location, and your position is not tracked or recorded over time.

We do not collect passwords, payment information, contacts, browsing activity, or any other personal information. If you do not use sunrise or sunset automations, no location is ever requested or stored.

How We Use Your Data

Your data is used only to operate the app's core features:

• Authenticating API requests to Tesla Fleet API
• Fetching live Powerwall status (charge level, grid state, power flow)
• Allowing you to change the operation mode and backup reserve
• Controlling grid charging and export settings
• Running automated schedules you configure in the app
• Calculating sunrise and sunset at your home, so automations set to sunrise or sunset run at the right moment as it shifts through the year

We do not use your data for advertising, behavioral profiling, or any purpose beyond what is listed above.

Where Your Data Is Stored

Your OAuth tokens, email address and (if you set one) your approximate location are stored in Firebase Firestore, a cloud database operated by Google Cloud, hosted in the us-central1 region (Iowa, USA). Data is encrypted at rest and in transit by Google's infrastructure.

No data is stored on your device beyond what the operating system caches temporarily during a session.

Third-Party Services

The app integrates with two external services:

• Tesla Fleet API – handles authentication via OAuth 2.0 and provides all Powerwall data and control endpoints. Tesla's own privacy policy governs how they handle data on their side. See tesla.com/legal/privacy .
• Firebase / Google Cloud – provides the backend database. Google's privacy policy applies to their infrastructure. See policies.google.com/privacy .
• Google Analytics – used on the public marketing website (powerwall-app.web.app) to measure page views and button clicks (for example App Store / Google Play). This is separate from in-app account data. See policies.google.com/privacy .

We do not share your data with any other third parties, and we do not sell, rent, or trade your information to anyone.

Your Rights and Choices

You are in control of your data:

• Access – you can contact us at any time to ask what data we hold about you.
• Correction – if any stored information is incorrect, let us know and we will fix it.
• Deletion – you can delete your account directly from within the app. This permanently removes your OAuth tokens, email and stored location from our database. Alternatively, email us and we will delete it manually.
• Location permission – you can withdraw the app's access to your device's location at any time in your device's system settings. This stops the app reading your position and does not affect anything else. Any location you have already saved stays until you delete your account, or ask us to remove it.
• Revoke Tesla access – you can revoke the app's access to your Tesla account at any time from Tesla Account Security settings . Revoking access invalidates the stored tokens immediately.

Data Retention

We retain your OAuth tokens and email for as long as your account is active. If you delete your account, all associated data is removed from Firestore promptly. Backups managed by Google Cloud may retain data for a short period thereafter in accordance with their backup rotation policy.

Children's Privacy

This app is not directed at children under 13. We do not knowingly collect personal information from anyone under 13. If you believe a child has provided us information, please contact us and we will delete it immediately.

Changes to This Policy

If we make material changes to this privacy policy, we will update the effective date at the top of this page. For significant changes, we will make reasonable efforts to notify users (for example, via an in-app notice). Continued use of the app after a change takes effect constitutes acceptance of the updated policy.

Contact

Questions, requests, or concerns about your privacy? Reach out any time:

Email: wangzishan1992@gmail.com

We aim to respond within 5 business days.