Battery Toolkit is a free, open-source app that controls charging on Apple silicon Macs. Amply is a paid app that turns on the charge limit built into macOS 26.4 and explains what the battery is doing. Both keep a MacBook below 100% while it sits on the charger.
Amply is our app, so this page is our side of it. Every Battery Toolkit fact here comes from its GitHub page, read on November 8, 2026. The sources are listed at the end.
How each one controls charging
Battery Toolkit sets a hard upper limit (50% at the lowest) and a lower limit where charging starts again (20% at the lowest). It can also turn the power adapter off without unplugging it, so the Mac runs down on battery. Its privileged operations go through a daemon.
Its README asks you to turn Optimized Battery Charging off while you use it. It also keeps the Mac awake while charging, so it can stop at the limit.
Amply uses the Charge Limit in System Settings instead. It runs as a normal app, never asks for an admin password and never writes to the chip that runs charging.
Which Macs each one runs on
Both need Apple silicon. Battery Toolkit gives install steps for macOS 14 and earlier and for macOS 15 and later. Amply needs macOS 26.4 or later. On an older macOS it can only watch the battery.
Battery Toolkit’s README adds that no app can control charging while the Mac is shut down, so a Mac left off on the charger fills to 100%.
What you get with each
Battery Toolkit is free under the BSD-3-Clause license, and anyone can read its code.
It is not notarized by Apple, so macOS blocks the first launch until you allow it in Privacy & Security. Its GitHub repository is archived (read-only), and the latest release, 1.8, came out in August 2025.
Amply is signed and notarized by Apple. It writes a plain sentence for every charging state and sends a notification when the limit stops holding, with 3 likely causes. It keeps battery health over 90 days, a year or since install, with a 1‑page PDF report.
| Battery Toolkit | Amply | |
|---|---|---|
| Price | Free, open source (BSD-3-Clause) | $9.50 once (50% off $19), after a 14-day free trial |
| How it limits charging | Its own limits, through a privileged daemon | The Charge Limit built into macOS 26.4 |
| Limit range | Upper from 50%, lower from 20% | 80% to 100%, the range of the macOS Charge Limit |
| Macs | Apple silicon | Apple silicon, macOS 26.4 or later |
| Turns the adapter off to run on battery | Yes | No |
| Notarized by Apple | No | Yes |
Which one to pick
- Pick Battery Toolkit if you want free and open source, a limit below 80% or a way to drain the battery while plugged in, and you are fine approving an app Apple has not notarized.
- Pick Amply if you are on macOS 26.4 or later and want Apple’s own limit explained in plain sentences, with a record of battery health.