Mac battery issues — short runtime, charging, swelling and service
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Quick answer
Mac battery issues fall into three categories: chemical wear (unavoidable after 800-1000 cycles), software management (Optimized Charging, Low Power Mode), and hardware faults (failing PMIC, charging circuit). If your battery is more than 4-5 years old, it's typically time for us to replace it.
Alle spørgsmål
Why does the battery only last a short time?
First: check cycle count and health under → About This Mac → System Information → Power. If the cycle count is over 800-1000 or health is below 80%, it's normal wear and the battery needs replacing. See current battery prices per model at macmo.dk/reparation.
Why does the battery percentage drop quickly?
Sudden rapid drain is either: 1) a background app pulling heavy power (check Activity Monitor → Energy), 2) a faulty battery cell that has lost capacity without showing it in the health figures, or 3) a faulty fuel-gauge IC reporting incorrectly. We can measure the actual capacity for you.
Why does my Mac only charge to 80%?
That's Optimized Battery Charging, a macOS feature that learns your habits. It holds the battery at 80% until 1-2 hours before you typically use it. This significantly extends battery lifespan. To turn it off: System Settings → Battery → Battery Health.
Why does my Mac say the battery needs servicing?
'Service Battery' or 'Replace Soon' means battery health has dropped below ~80%. Your MacBook still works, but runtime is reduced. This is the right time to get it replaced — don't wait for it to swell. Price: DKK 1,200-2,400 with us.
Why does the battery get warm?
Warm batteries during charging are normal up to a limit (40-45°C). If the battery becomes burning hot, or hot even when not in use, it's faulty and needs replacing fast — it's a safety risk. Shut down the Mac, unplug the charger and contact us.
Why is the battery swelling?
A swollen battery is a chemical reaction (gas formation in the cells) that occurs from overheating, faulty cells or simply an old battery. It pushes the trackpad and logic board upward and can cause shorts. STOP using the MacBook, shut it down, and bring it to us as soon as possible. The fire risk is real.
Why does my Mac lose power in sleep?
A healthy Mac normally loses less than 5% battery per night in sleep. Larger losses mean either: 1) Power Nap is enabled (fetching mail, running backups) — turn it off in System Settings → Battery, 2) an app is keeping the Mac partly awake (Bluetooth devices, external drives), or 3) a faulty battery leaking current.
Why does my Mac shut down at 20%?
Spontaneous shutdowns well above 0% are a classic symptom of a faulty or expanded battery cell. The fuel gauge thinks 20% is left, but in reality it's 0%. The cell can no longer hold voltage under load. It needs replacing — contact us.
Why does the battery drain quickly in standby?
Standby drain over 5% per night is typically caused by: 1) Bluetooth devices constantly pinging, 2) Wake-on-LAN enabled, 3) Time Machine or iCloud running overnight, 4) a small hardware fault holding the logic board in a higher power state. An SMC reset (Intel) often solves the last one.
Why does the battery charge slowly?
Slow charging is caused by: 1) an underpowered charger (Air needs 30W+, 16-inch Pro needs 96W+), 2) Optimized Charging deliberately slowing things down past 80%, 3) the battery being very warm (close apps, let it cool), or 4) a faulty charging circuit. Check the wattage printed on your charger.
Why does the battery stop at 95%?
That's still Optimized Charging. macOS holds the battery below 100% when it knows you don't need it fully charged. If you need a full charge right now, click the battery icon in the menu bar and choose 'Charge to Full Now'. Turn off Optimized Charging if it bothers you.
Why does the battery percentage show incorrectly?
The fuel-gauge IC learns the battery's actual capacity through full charge/discharge cycles. If you always keep the battery between 30-80%, the gauge loses calibration. Let the battery drain completely (down to 0, until the Mac shuts off) and then charge to 100% without interruption. That recalibrates it. If the problem persists, the fuel gauge or battery is faulty.