Skip to content

Add live battery power rate display #2

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
git-anish wants to merge 2 commits into
base: main
Choose a base branch
from
Open

Add live battery power rate display #2

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
be501ed
Add live battery power rate display
git-anish Mar 14, 2026
3270d93
Add unplugged display preference
git-anish Mar 14, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 2 additions & 1 deletion .gitignore
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1 +1,2 @@
**/xcuserdata/
.DS_Store
build/
73 changes: 66 additions & 7 deletions README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,10 +1,69 @@
# WhatWatt
USB-C charging can be shrouded in mystery, especially when you have an unfamiliar cable or power adapter, or you have one of those multi-port chargers that has all sorts of arbitrary rules for how it splits power between plugged-in devices. That's why I wrote this little menu bar utility that displays how much power your computer (thinks it) is charging with. I designed this app to be simple and unobtrusive, and light on system resources--it only updates when it detects a change in charging status.
# WhatWatt Power Rate

**Note:** This app can only report what the system is requesting from the charger, which may not necessarily reflect actual values. Think of it as displaying your computer's charging "mode" rather than actually measuring power directly.
A lightweight macOS menu bar app that shows both:
- adapter wattage requested from the charger
- live battery charge or discharge rate

## Compatibility
This app is compatible with Intel and Apple Silicon portable Macs running **macOS 10.13 "High Sierra"** or newer. Although intended for Macs that charge via USB-C/MagSafe 3, this app also partially supports older MagSafe 1 and 2 Macs (though you might not see current/voltage information)
This repo started from [SomeInterestingUserName/WhatWatt](https://github.com/SomeInterestingUserName/WhatWatt) by Jiawei Chen and keeps the original MIT license.

## Installation
Hop on over to the [Releases](https://github.com/SomeInterestingUserName/WhatWatt/releases) to grab your copy of WhatWatt! I'm not enrolled in the Apple Developer Program, so your computer might not trust me. If it refuses to open the app, just right-click and select "Open" from the menu.
## What changed

This fork adds the behavior requested for day-to-day charger debugging:
- battery charge and discharge rate in watts, derived from `AppleSmartBattery` current and voltage
- event-driven low-power refresh behavior
- default low-power mode: `60s` idle refresh
- burst mode: `1s` refresh for `20s` after a real charger-state change
- menu toggle for `Always Live Updates`
- lightweight `Preferences...` window for tuning live interval, burst duration, and idle interval
- cleaner menu bar title format such as `67W | ↑18.4W` while charging and `↓18.4W` when unplugged
- optional `Show 0W adapter when unplugged` preference if you prefer the explicit adapter state in the menu bar
- Intel-safe signed current handling for wrapped battery amperage values

## Why this exists

The original app is excellent for showing negotiated adapter wattage, but it does not expose the current battery power flow. This fork is aimed at people who want to answer questions like:
- Is the battery actually charging right now?
- At what rate is it charging or discharging?
- Did plugging in this cable or charger change only the negotiated adapter wattage, or the real battery power flow too?

## Telemetry caveat

Battery power values come from macOS battery telemetry. Even when the app refreshes every second, the underlying battery readings may update more slowly or appear smoothed by the system, so visible changes often land on a cadence closer to a few seconds rather than every exact second.

## Build

### With Xcode

1. Open `WhatWatt.xcodeproj` in Xcode.
2. Select the `WhatWatt` target.
3. Build for the architecture you want on that machine.

### With Command Line Tools

On Intel Macs, you can build with `swiftc` and the macOS SDK from Command Line Tools:

```bash
mkdir -p build/WhatWatt.app/Contents/MacOS build/WhatWatt.app/Contents/Resources
swiftc -sdk /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -framework Cocoa -framework IOKit WhatWatt/main.swift WhatWatt/AppDelegate.swift WhatWatt/ViewController.swift -o build/WhatWatt.app/Contents/MacOS/WhatWatt
cp WhatWatt/Info.plist build/WhatWatt.app/Contents/Info.plist
codesign --force --deep --sign - build/WhatWatt.app
```

## Release strategy

This project should publish separate binaries instead of pretending one local machine can always produce both cleanly.

- Intel release: build on Intel and publish an `x86_64` app bundle.
- Apple Silicon release: build on Apple Silicon and publish an `arm64` app bundle.
- Optional universal release: if needed later, combine vetted `x86_64` and `arm64` binaries with `lipo` and package that separately.

That keeps distribution explicit and avoids shipping untested cross-compiled binaries.

## License and credit

Original project:
- Author: Jiawei Chen
- Repo: [SomeInterestingUserName/WhatWatt](https://github.com/SomeInterestingUserName/WhatWatt)
- License: MIT

This fork remains under the MIT license. See `LICENSE`.
Loading