Privacy Policy

Scope and contact

This policy describes how the BatterySync team handles information in the BatterySync Android app, Chrome extension, website, and connected backend. Last updated: 3 November 2026.

For privacy questions, access or correction requests, or account and data deletion, use https://batterysync.netlify.app/contact and choose Data Deletion or Account Help as appropriate. You do not need to install the app to submit a request.

Account, device, and battery information

When you sign in with Google, BatterySync processes your Google account identifier and may store your email address, display name, and profile photo URL. The Chrome extension links to your account using a short-lived, single-use login code generated in the app. Authentication and refresh tokens keep your devices signed in.

Connected device records include installation or device identifiers, device names and aliases, device type, manufacturer or model where available, Bluetooth names and addresses where supplied by the app, battery percentage, charging status, battery temperature where available, online status, and sync timestamps. We also store alert preferences, silent hours, push-registration tokens, and the status of remote actions. These records support cross-device battery monitoring, notifications, synchronization, and device management.

Optional media and call features

When you enable media sharing or controls, BatterySync processes the current media title, artist, album, player or app name and identifier, playback state, supported controls, volume, mute state, and update timestamps. For Chrome, the app name is the media page hostname and the title may be the page title when Media Session metadata is unavailable. A page title can contain personal information. The selected player state is sent to the BatterySync backend and made available to devices authorized to view or control it.

Chrome media sharing is off by default. Enabling it requests optional access to HTTP and HTTPS websites so the extension can detect and control HTML audio or video. Scripts run in accessible frames, but the extension shares one selected player state per browser. It does not upload a general browsing-history log, full page URLs, page bodies, or audio/video recordings. Turn off Share Chrome media in extension settings to stop sharing, or revoke website access in Chrome.

On Android, media controls require the relevant device settings and system access. If you enable pause-on-call and grant phone-state access, the app detects an incoming ringing state and sends a pause command to eligible connected players. This feature does not inspect the incoming phone number, upload call audio, or upload your call history. Remote media and ring requests include target and request identifiers and command status so actions can be routed, expired, and acknowledged.

Permissions and local storage

Android Bluetooth and Nearby Devices access support connected-device discovery and battery features. Older Android versions may require location permission for Bluetooth discovery. Notifications and background execution support alerts and sync; optional overlay access supports floating controls. You can manage granted permissions in Android settings, and features that need a denied permission may be unavailable.

The Chrome extension uses storage for credentials, settings, and cached device readings; alarms for periodic sync; notifications for battery alerts; an offscreen document for browser battery readings; and scripting for optional media sharing. Credentials and device caches are restricted to trusted extension contexts. Chrome local extension storage is persistent storage, not a promise of application-level encryption. Signing out clears local account credentials and device caches; uninstalling removes extension-local data. Signing out or uninstalling does not itself delete cloud account records.

Device sharing and recipients

Information is synchronized to devices signed in to your account. If you create or accept a device share, the recipient receives device information or access to alerts, remote ring, or media controls according to the granted permissions. Review recipients and revoke shares you no longer want. A recipient may retain information they already saw or copied.

BatterySync backend and website infrastructure process requests to deliver the service. Authorized support or administrative access is used for support you request, maintaining and securing the service, investigating abuse, and handling deletion requests. Information may also be disclosed when required by law or necessary to protect users and the service.

Google services in the Android app

The Android app integrates Google Sign-In for authentication, Firebase Cloud Messaging for push delivery, Firebase Analytics for app usage measurement, Firebase Crashlytics for reliability diagnostics, and Google Mobile Ads (AdMob) for advertising. These are Google services and have their own privacy practices at https://policies.google.com/privacy. The Chrome extension does not embed these Android analytics or advertising SDKs.

Analytics and crash diagnostics may include app interactions, installation identifiers, app and operating-system versions, device characteristics, crash stack traces, and diagnostic logs. Release builds enable Crashlytics; normal debug builds disable crash upload unless explicitly enabled for testing.

Google Mobile Ads may process IP addresses, device or account identifiers, ad interactions, and diagnostics for ad delivery, measurement, and fraud prevention. IP addresses can indicate approximate location. The app currently configures child-directed and under-age-of-consent ad treatment with a general-audience content rating; these settings do not mean that no advertising data is processed. Advertising processing is separate from the Chrome extension data described below.

Chrome extension Limited Use

BatterySync uses data obtained through the Chrome extension only to provide and improve its disclosed battery synchronization and related device-control features, including their security and reliability. We do not sell extension user data, transfer it to advertising platforms or data brokers, use it for personalized advertising, or use it to determine creditworthiness or lending eligibility.

Transfers of extension data are limited to delivering or improving these features, complying with applicable law, preventing fraud or abuse, or a merger or acquisition with explicit prior user consent. Human access to extension user data is limited to specific data you consent to share for support, aggregated and anonymized operational information, security investigations, or legal requirements.

Website and support requests

The website contact form collects your name, email address, request category, subject, and message, along with submission time, request source, IP address, and browser user-agent information. We use this information to respond, verify account ownership where necessary, process deletion requests, and prevent abuse. Do not submit passwords, authentication tokens, or login codes in the form.

Website hosting and API providers receive the network information necessary to serve pages and process requests. The current website does not embed the Android advertising or Firebase SDKs. Your browser may store settings and temporary assets for website functionality.

Retention and deletion

Account and device records remain in the service until they are removed or a deletion request is completed; signing out does not automatically erase them. Current media state is updated as playback changes and stops being presented as current after it becomes stale. Stale-state display limits and command expiry are not a guarantee that all database records or backups have been erased.

Support requests are retained for handling requests, documenting their outcome, and security or legal needs. The service does not currently apply a single automatic deletion period to all account, device, and support records. Retention also depends on the relevant infrastructure or Google service. We do not promise a fixed backup-erasure date.

To request deletion of your account and associated synced device information, use the Data Deletion option at https://batterysync.netlify.app/contact?type=DATA_DELETION. Include enough information to identify your account and specify whether you want the whole account or particular devices removed. We may request ownership verification, explain any information that must be retained, and respond about the outcome. Revoking Google sign-in access, deleting a device, signing out, and uninstalling are separate actions.

Security, choices, and international processing

Production app and extension API connections use HTTPS. Authentication and server-side authorization restrict access, and refresh-token hashes are stored on the backend. Data can also be stored locally on your device. These controls reduce risk but cannot guarantee absolute security.

You can disable optional media sharing, manage Android and Chrome permissions, stop sharing devices, sign out, and request access, correction, or deletion through support. Depending on your location, you may also have rights to object to or restrict processing, withdraw consent, request portability, or complain to your local data-protection authority.

BatterySync infrastructure and Google services may process information outside your country. Applicable service-provider terms and legal safeguards govern those transfers. Contact support for information about your request or the services involved.

Children and policy changes

BatterySync does not request your date of birth. If you are below the age at which you can authorize data processing where you live, use the service only with the involvement of a parent or guardian as required by local law. Parents or guardians can contact support about a child’s information or request deletion.

We update this policy as the app, extension, or data practices change and update the date above. Material changes that require additional notice or consent will be communicated through the service or its published channels before the new processing begins.