litGitHub
Free & open source · macOS 14 and later

Never get caught with a dead battery again

lit watches your Mac’s battery so you don’t have to — custom alerts, real health data, and charging habits that make the battery last longer. No account, no subscription, no catch.

macOS gives you one low-battery warning, no health data, and no idea what’s connected to your Mac or how much charge it has left. lit is the menu bar app that actually tells you what’s going on.

Everything your Mac’s battery menu should’ve had

Custom battery alerts

Add any threshold — 3%, 20%, whatever matters to you — and get a real macOS notification the moment you cross it while unplugged.

Battery health tracking

Live health percentage, cycle count, and temperature, read straight from the same data macOS itself uses.

Bluetooth device battery

AirPods, Beats, Magic Mouse, keyboard, trackpad — anything reporting standard HID battery, listed with color-coded levels.

Lifecycle alerts

Notified when you plug in, unplug, and when you hit 80% while charging — the cue to unplug for long-term battery health.

Themeable menu bar icon

Icon + percentage, percentage only, or icon only — an iPhone-style battery glyph that color-codes itself as it drains.

Native & fast

Real Swift, not Electron. Idles at roughly 0% CPU. Everything is computed on-device — nothing leaves your Mac.

On the roadmap

Being upfront: these aren’t built yet. They’re the harder, system-level pieces we’re working through in the open.

Charge limiting / healthy band

Cap charging at 50–80% to slow long-term degradation. Needs a privileged helper to write SMC charge-control keys, so it's a bigger, careful build.

Per-app energy insights

See which apps are draining your battery right now, with 24h/7d/30d history. Likely needs the private IOReport framework — under investigation.

iPhone / iPad battery health

Plug in your phone or tablet and see its health, cycle count, and temperature too, no extra app required.

Predictive, calendar-aware alerts

"You'll be under 20% by the end of your 2pm meeting" — reading your calendar so you're never caught out mid-call.

Built for how you actually work

Working from a cafe with no outlet

Set alerts at 10% and 5% so you know exactly how much runway you have left before you need to wrap up.

Keeping your battery healthy

An 80% alert while charging is your cue to unplug — the single habit that does the most for long-term battery lifespan.

Deep focus work

A 20% and 15% warning gives you time to save and wrap up before the screen goes dark mid-thought.

Presentations and client calls

Early alerts at 25% mean you're never scrambling for an outlet mid-pitch.

Free. Open source. Yours.

lit is MIT-licensed and built in the open. No trial, no license key, no paywalled features — clone it, build it, or grab a signed release. Everything runs locally; nothing phones home.

Questions? We’ve got answers.

Is it actually free?

Yes — MIT licensed, no trial, no license key, no paywalled features. Build it from source or grab a signed release from GitHub.

Does it collect any data?

No. Battery and device readings are computed on-device and never leave your Mac. There's no account, no analytics, no cloud sync.

What macOS versions does it support?

macOS 14 and later, on both Apple Silicon and Intel.

How is this different from the built-in battery menu?

Custom alert thresholds instead of one fixed low-battery warning, real health/cycle/temperature data, Bluetooth accessory battery levels in one place, and lifecycle alerts for healthier charging habits.

Can I trust an open source battery app with system access?

Every line is public on GitHub — read it, build it yourself, or audit exactly what it does before you trust it with your Mac.