Who We Are
TeslaBatteryCheck.com is a free tool that helps Tesla owners monitor battery health, estimate degradation, and plan charging. The site is operated by Thomas Boyd as an independent project. We are not affiliated with Tesla, Inc.
Information We Collect
Account data (optional)
If you create an account via our garage feature, we collect your email address and an encrypted password (or Google account identifier if using Google Sign-In). This is processed by Supabase, our authentication and database provider.
Vehicle & battery data
When you use the garage feature, you may enter vehicle details (model, year, variant, nickname, odometer) and battery readings (Wh, range, percentage, capacity). If you're signed in, this data is stored in our cloud database (Supabase). If not, it's stored only in your browser's localStorage and never leaves your device.
Usage & analytics data
With your consent (or unless you opt out), we use Google Analytics 4 to collect anonymised usage data such as pages visited, referring site, browser type, device type, and approximate location (country/city level). Google Analytics uses cookies to distinguish users across sessions.
Advertising data
We use Google AdSense to display ads. AdSense may use cookies to serve ads based on your prior visits to this site or other sites. You can opt out of personalised advertising at Google Ads Settings.
Local storage
We use your browser's localStorage to save preferences (language selection, PWA install prompt dismissal) and, for non-authenticated users, garage vehicle and reading data. This data never leaves your device unless you sign in and migrate it to the cloud.
How We Use Your Information
- To provide and maintain our battery health tools and calculators
- To store your vehicle data and battery readings in your garage
- To authenticate your account if you sign up
- To analyse site usage and improve our tools (via Google Analytics)
- To display relevant advertisements (via Google AdSense)
- To provide route planning (via HERE Maps and OpenStreetMap/Leaflet)
- To remember your language preference and settings
Third-Party Services
We use the following third-party services that may process your data:
| Service | Purpose | Data shared |
|---|---|---|
| Google Analytics 4 | Site analytics | Page views, events, device info, approximate location |
| Google AdSense | Advertising | Browsing behaviour for ad personalisation |
| Supabase | Authentication & database | Email, vehicle data, battery readings |
| Google Fonts | Font delivery | IP address (for font loading) |
| HERE Maps | Route planning | Locations entered for route calculations |
| OpenStreetMap / Leaflet | Map tiles | Map viewport coordinates |
Data Retention
- Account & garage data: retained as long as your account exists. You can delete your account and all associated data at any time.
- localStorage data: stored on your device until you clear your browser data or we remove it programmatically.
- Analytics data: Google Analytics retains data for 14 months by default.
- Cookie consent preference: stored indefinitely in localStorage until you clear it or change your choice.
Data Storage & Security
Cloud data is stored securely on Supabase infrastructure with row-level security policies ensuring users can only access their own data. All data is transmitted over HTTPS. Passwords are hashed and never stored in plain text.
While we take reasonable measures to protect your data, no method of transmission or storage is 100% secure. We cannot guarantee absolute security.
Children's Privacy
Our service is not directed to children under 16. We do not knowingly collect personal information from children. If you believe we have collected data from a child, please contact us and we will delete it promptly.
Deleting Your Data
- Garage data (local): clear your browser's localStorage or site data
- Account & cloud data: contact us to request full account deletion, or delete individual vehicles/readings from the My Garage page
- Cookies: manage or revoke consent via our Cookie Policy, or clear cookies in your browser settings
- Google Analytics data: install the Google Analytics Opt-out Browser Add-on
Changes to This Policy
We may update this privacy policy from time to time. Changes will be posted on this page with an updated "last updated" date. Continued use of the site after changes constitutes acceptance of the updated policy.
Contact Us
If you have questions about this privacy policy or want to exercise your data rights, contact us at:
privacy@teslabatterycheck.com