Guide · macOS 27
macOS 27 and charge limits: why battery apps stopped working
macOS 27 locked the controls charge limiters used. Updated apps set macOS’s own charge limit instead, and some features, like draining, are gone.
If your charge limiter suddenly let your MacBook charge to 100% after you updated to macOS 27, you weren’t imagining it. Apple changed how charging can be controlled, every limiter had to adapt, and some things they used to do aren’t possible any more.
What changed in macOS 27
Charge limiters on Apple silicon used to write to a handful of keys in the Mac’s System Management Controller (SMC), the chip that runs charging. One key stopped charging, another cut the charger so the Mac ran on its battery. Developers report that with macOS 27’s firmware (from beta 4 on), those charge-control keys answer “not permitted” even to apps running as root, and are reserved for processes with a private Apple entitlement.
What Apple left open is its own charge limit. The service behind System Settings’ Charge Limit setting accepts requests from other apps, so updated limiters now ask macOS to hold the limit, and macOS enforces it itself, through sleep too.
Which charge limiters work on macOS 27
| Feature |  |  |  |  |  |  |
|---|---|---|---|---|---|---|
| Works on macOS 27 | Yes (1.1+) | Yes (1.39+) | Yes (BatFi 4) | Yes (0.9.0) | No release yet | Built in |
| Limits | 80–100% | Below 80% with a toggle | Any limit | 10–99% | — | 80–100% |
| Drain while plugged in | No | Not stated | Not stated | Opt-in adapter mode | No | No |
| Heat pausing | No | Not stated | No | No | No | No |
From each developer’s release notes and pages: AlDente 1.39, BatFi’s site (its heat pause works only on Macs that have never had macOS 27), batt 0.9.0. “Not stated” means the developer’s macOS 27 notes don’t say.
What you lose on macOS 27
- Draining with the charger plugged in. While macOS’s limit is in charge, the firmware ignores the switch that cut the charger. (batt’s opt-in adapter mode cuts wall power another way.)
- Pausing for heat, in the apps that used the same switches.
- Exact control. macOS decides when charging stops and starts again, and still charges to 100% now and then to check the battery.
What keeps working: the limit itself, charging to 100% when you ask, and everything an app does on top, like schedules, notifications and health records.
Chargeberry on macOS 27
Since version 1.1, Chargeberry notices when the charging controls are locked and sets macOS’s own Charge Limit instead. Your limit, Charge to 100%, Full by and its schedules, shortcuts, alerts, the health history and Battery Wrapped all keep working. Limits below 80%, drain down, calibration and heat pausing are turned off there, and the app says so. If you had set macOS’s Charge Limit yourself, Chargeberry gives it back as it was when you turn its limit off or uninstall it.
According to Chargeberry’s 1.1 release notes, on Macs where macOS 27 locks the charging controls, Chargeberry sets macOS’s own charge limit for you, from 80% to 100%, along with Charge to 100%, Full by and its schedules.
Setting up a limit on macOS 27
Update your app first
Make sure your limiter supports macOS 27 (Chargeberry 1.1, AlDente 1.39, batt 0.9.0, BatFi 4 or later).
Remove old helpers
If you’ve switched apps, remove the old app’s helper too, not just the app. Leftovers can get in the way of the new limit.
Turn off Optimized Battery Charging
System Settings › Battery › ⓘ next to Charging. One thing deciding when to charge is enough.
Choose your limit
In your app, or in System Settings’ Charge Limit if you don’t use one. 80% suits most people.
- Health
- 83%
- Cycles
- 349 of 1000
- Temperature
- 30.8 °C
- Charger
- 30 W
A working model of Chargeberry, not a video, running the same charging rules as the app. Plug the charger in and out, change the limit, turn up the heat, try Charge to 100% and Full by. Time runs fast here: two minutes every second, and faster with S.
Questions about macOS 27 and charge limits
Does macOS 27 have a charge limit?
Yes. macOS’s own Charge Limit, added in macOS Tahoe 26.4, is in macOS 27 too: System Settings › Battery › ⓘ next to Charging, from 80% to 100%, on Macs with Apple silicon.
Why did AlDente stop working on macOS 27?
Versions made before macOS 27 used SMC charging keys that macOS 27 firmware now reserves for Apple’s own processes. AlDente 1.39 rebuilt its charge control for macOS 27, so updating fixes it.
Can I still drain the battery while plugged in on macOS 27?
Mostly not. With macOS’s own charge limit in charge, the firmware ignores the switch apps used to cut the charger. batt offers an opt-in adapter mode that cuts wall power instead, which works only while batt is awake. Chargeberry turns drain off on macOS 27.
Is it safe to use a charge limiter on macOS 27?
Yes, with an app updated for it. They now use macOS’s own charge-limit service, the same one System Settings uses, and macOS enforces the limit itself.
Will Chargeberry support limits below 80% on macOS 27?
Not today: on macOS 27, Chargeberry 1.1.2 offers the limits macOS lists, 80% to 100%. Other apps now set lower targets through the same service; if Chargeberry adds that, its changelog will say so.