Battery is a free, open-source macOS utility that keeps your MacBook's battery health in check by capping the charge level and preventing the constant topping-up that silently degrades lithium cells over time.
What is Battery?
Battery is a lightweight macOS menu-bar app — with an accompanying command-line interface — that intercepts the charging cycle on Apple Silicon and Intel MacBooks to hold the charge at a user-defined ceiling, typically 80%, rather than letting it perpetually sit at 100% plugged in. It was built by Mentor Palokaj and lives entirely on GitHub under an open-source licence, free to inspect and free to use.
The concept is well-established in battery science: lithium-ion cells age fastest when they spend hours fully saturated with current. Every hour your MacBook idles at 100% on the charger is wear you can't get back. Battery solves this with a software-level charging limit that works quietly in the background without any subscription, paywall, or telemetry.
What does Battery do best?
Battery's core superpower is its dead-simple charge ceiling: set it to 80% once and forget it. The app communicates with macOS's power management layer to pause charging at that threshold, then resumes automatically if the battery dips below a configurable floor — so you never wake up to a dead laptop, even on long overnight sessions.
Beyond the menu-bar toggle, the companion CLI is genuinely useful for power users and automation scripts. You can query charge status, flip the limit, or force a full charge ahead of a flight — all from a terminal without touching the GUI. I've wired it into a shell alias so one keystroke gives me an unrestricted charge before travel days.
- Configurable ceiling — any percentage you choose, not just a hardcoded 80%
- Automatic resume — resumes charging at a floor you define (default: 75%)
- CLI bundled — scriptable with battery charge 80, battery status, and more
- Menu-bar indicator — glanceable charge state without opening System Preferences
- No cloud, no account — entirely local; the GitHub repo is public for audit
Is Battery free?
Yes — Battery is completely free to download and use, with no premium tier, no in-app purchases, and no nag screens. It's distributed via GitHub Releases and installable through Homebrew Cask (brew install --cask battery). The author accepts donations but charges nothing for the software itself.
Who should use Battery?
Anyone who leaves their MacBook plugged in for hours at a stretch — which is most knowledge workers. If your machine lives docked to a monitor for the better part of the day, the cumulative wear from constant 100% charging adds up fast. Battery is the fix with the lowest friction I've found: one install, one slider, done.
It's especially valuable on older machines where battery replacement is expensive, or on newer Apple Silicon models where a healthy battery means years of full-day untethered use. Developers will appreciate the CLI for dotfile scripting; non-technical users will be satisfied with the menu-bar alone.
Where Battery is less relevant: if you frequently need maximum range and rarely sit at a desk, the restricted ceiling will annoy you more than it helps. And if you're on an Intel Mac with a deeply degraded battery, Battery won't undo existing cycle damage — it's prevention, not repair.
What are the best Battery alternatives?
AlDente is the most direct competitor: it covers similar charge-limiting ground with a polished UI and some extra features (heat protection, sailing mode) behind a paid Pro upgrade. AlDente Pro is worth considering if you want a single GUI for every scenario without touching a terminal. Battery wins on price (entirely free) and transparency (fully open source).
Apple's own Optimised Battery Charging, built into macOS, learns your routine and delays charging past 80% before you typically unplug — a reasonable default, but it adapts rather than enforces, and it can't be scripted. Battery gives you hard, predictable control that Optimised Charging deliberately avoids. For users who travel irregularly or have unpredictable schedules, Battery's explicit ceiling beats Apple's statistical guess every time.
How does Battery compare to AlDente?
Both apps target the same problem and both work well. AlDente has a friendlier onboarding experience and a broader feature set in its Pro tier; Battery is leaner, fully free, and ships with a first-class CLI that AlDente lacks at the free level. If you live in the terminal and hate paywalls, Battery is the clear choice. If you want a polished GUI with heat protection and sailing mode without scripting anything, AlDente Pro is worth the one-time fee.
