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WattMate

WattMate is a local battery diagnostics app for Apple silicon Macs on macOS 14+. See app power use in watts, estimated battery time, and post-quit measurements.

WattMate

Local battery diagnostics for Apple silicon Macs

WattMate is a local macOS battery diagnostics app for Apple silicon Macs. It identifies which apps are using measurable processor energy, reports their estimated contribution in watts, and translates the current load into a projected number of battery minutes that could be recovered by quitting an app.

The app also compares its projection with a real post-quit measurement: while the Mac is on battery, it measures again about two minutes after an app is closed and prints what changed. WattMate includes battery health readings, charging diagnostics, overnight wake records, and session summaries, while explicitly separating app-attributed work from screen, system, graphics, and other energy it cannot assign to a single app.

Features

Per-app watt readings

Shows app-level power use in watts, grouping helper processes with the app that started them instead of presenting macOS's unitless Energy Impact score.

Battery-time projections

Estimates how many minutes of battery time could return if you quit an app, based on the Mac's current remaining time and measured app load.

Quit receipts

About two minutes after an app is quit while the Mac is on battery, measures the Mac again and reports what actually changed, including when the effect cannot be isolated.

Battery and charging diagnostics

Displays battery capacity, cycle count, and temperature, and can also show delivered, consumed, stored, and spare power when connected to an adapter.

Monitored app alerts

Lets users star an app, place its icon and watt reading in the menu bar, review a last-hour verdict, and receive a one-time notification when a configured power threshold is exceeded.

Session and overnight history

Keeps detailed charge data for two days and retains compact session summaries until the user erases them, allowing recent battery sessions and overnight wake activity to be reviewed.

Use cases

  • Investigate rapid battery drain

    When the battery is dropping quickly, inspect the live app list to find the largest measurable contributor and see the projected minutes associated with quitting it.

  • Decide what to quit

    Before closing a browser, editor, call app, or other demanding workload, use the projection as a decision aid, then check the quit receipt to see whether the expected improvement appeared.

  • Watch a background-heavy app

    Star an app that should normally run quietly, keep its watt reading in the menu bar, and use the last-hour verdict or threshold notification to catch background activity.

  • Diagnose charging shortfalls

    When a Mac remains on battery while plugged in, inspect adapter delivery, total demand, shortfall, and the apps associated with measurable load.

  • Review overnight and historical use

    Review overnight wake names and durations or consult session summaries to understand what consumed charge during sleep and how recent battery sessions were spent.

Pros and Cons

Pros

  • Reports per-app power in watts rather than macOS's unitless Energy Impact score.
  • Provides a post-quit receipt that checks the projected battery benefit against what the Mac actually did.
  • Includes battery health, charging, overnight wake, and session-history views.
  • Measurement and per-app data remain local to the Mac, with controls for anonymous usage statistics and crash reports.

Cons

  • Requires an Apple silicon Mac running macOS 14 or later; Intel Macs are not supported.
  • App-level attribution is incomplete for graphics and Neural Engine energy, and battery-time figures are estimates rather than guarantees.
  • The first battery-time estimate may take several minutes and can take longer after unplugging or waking from sleep.

FAQ

What does WattMate need to run?

WattMate requires macOS 14 or later and an Apple silicon Mac. It reads counters exposed by macOS and does not require a password prompt or helper installation.

How quickly does WattMate show results?

The app list appears within seconds. Battery-time estimates require measurement windows; the site says the first figure arrives within about three minutes half the time, and sometimes takes longer. The app does not show a countdown.

Does WattMate send measurement data anywhere?

The app measures battery or board and adapter power locally, then works out app attribution and projected time savings. Per-app measurements are not sent off the Mac. Anonymous usage statistics and crash reports are enabled by default but can be disabled in Settings.

What remains available after the trial?

The ten-day trial includes the full app and starts the first time you open it, with no card or account required. After the trial, the app continues to show the app list, watts, battery health readings, the last run, and the most recent night; battery-time estimates and deeper historical features require a paid key.

What are WattMate's measurement limits?

WattMate identifies measured graphics energy as a total rather than assigning it exactly to individual apps. Neural Engine energy is not attributed to an app, and some power belongs to the screen, system, or background work. Estimates are shown conservatively and a quit receipt is provided when the result can be checked.

Quick Facts

Category
Mac battery diagnostics
Platform
Apple silicon Mac; macOS 14 or later
Distribution
Mac App Store and Homebrew cask
Trial
10 days; no card or account required
Core output
Per-app watts, projected battery minutes, and post-quit measurements
Data handling
Per-app measurements and storage are local