Feature · 充電
A daily charge cap,and a weekly cycle to keep it honest.
Lithium-ion wears fastest at the extremes, and hours parked at 100% are the part you control. Set a daily cap and charging stops there. Once a week, Sensei suggests a fuller cycle so the runtime estimate stays honest.
Why it matters
You can't repair a battery, but you can slow the wear. A cap trades runtime you weren't using for capacity you'll want in two years. The weekly cycle keeps the gauge calibrated, so you can watch the trade pay off.
Why capping charge helps
Lithium-ion cells age fastest at the extremes. Time spent sitting at 100%, especially warm and especially plugged in overnight, is the single most controllable contributor to capacity loss. Holding the pack lower on ordinary days trades a little runtime you probably weren't using for slower long-term wear.
This isn't a replacement for Apple's Optimized Battery Charging, which delays the last stretch of a charge based on learned routine. Battery Sensei shows that setting's live state alongside its own cap, so you can see which mechanism is holding the charge back.
Picking a number
- 80% is the common default: meaningful reduction in high-state-of-charge time, still a full working day for most people. Sensei badges 85% as its in-app recommendation, half a step up for anyone who wants a little more runtime in reserve.
- 90% suits people who regularly need the runtime and want a gentler trade.
- 100% turns the cap off entirely: the right answer before travel, and Sensei stops nagging about weekly cycles when you're there.
The weekly full cycle
A pack that never leaves a narrow band gives the battery controller less to calibrate against, and runtime estimates drift. With a cap set, Sensei surfaces a weekly reminder to run one fuller cycle, enough to keep the gauge honest without undoing the benefit of the cap. See calibration for the mechanism, and Saga for whether it's working over time.
Frequently asked.
- Does a charge limit actually extend battery lifespan?
- It reduces time spent at high state of charge, which is one of the well-documented stressors on lithium-ion cells alongside heat and deep discharge. It's a slow effect measured over months, not something you'll see next week.
- Does this conflict with Optimized Battery Charging?
- No. Apple's feature delays the final charge stretch based on your routine; the cap sets a ceiling. Battery Sensei shows both states so you always know which one is in control.
- What happens before a trip?
- Set the cap to 100% (or use Travel Mode) and charge fully. Sensei also pauses the weekly full-cycle reminder while the cap is off.