How to check your MacBook’s battery health

The quick answer

Open System Settings › Battery and look at Battery Health. It says Normal or Service Recommended. Click the ⓘ next to it to see Maximum Capacity, a percentage of what the battery held when new.

For the cycle count, use Terminal:

system_profiler SPPowerDataType | grep -A3 "Health Information"

      Health Information:
          Cycle Count: 412
          Condition: Normal
          Maximum Capacity: 91%

That’s the same data System Information › Hardware › Power shows, without clicking through it. Hold Option, click the Apple menu and choose System Information if you prefer the window.

The real numbers, in mAh

The percentage is rounded and smoothed. The battery controller reports the raw values to IOKit, and ioreg reads them:

ioreg -rn AppleSmartBattery | grep -E '"(CycleCount|DesignCycleCount9C|DesignCapacity|AppleRawMaxCapacity|NominalChargeCapacity|Temperature)"'

      "NominalChargeCapacity" = 4609
      "DesignCycleCount9C" = 1000
      "Temperature" = 3053
      "DesignCapacity" = 6075
      "CycleCount" = 1044
      "AppleRawMaxCapacity" = 4459

What each one means:

Key	Meaning
DesignCapacity	What the battery held when new, in mAh
AppleRawMaxCapacity	What it holds at full charge today, in mAh
NominalChargeCapacity	A smoothed version of the same, in mAh
CycleCount	Full charge cycles so far
DesignCycleCount9C	Cycles Apple rates it for (1,000 on MacBooks)
Temperature	Battery temperature in hundredths of a °C (3053 = 30.5 °C)

Divide raw capacity by design capacity for your own health figure. In the example, 4459 ÷ 6075 is 73%. That battery has passed its 1,000 rated cycles and macOS marks it Service Recommended.

On Apple Silicon, ignore MaxCapacity and CurrentCapacity in the same output. They are percentages (MaxCapacity is always 100), not mAh, which trips up a lot of older scripts and blog posts.

How to read the result

• Cycle count under 300 and capacity above 90%: a young battery. Nothing to do.
• Capacity between 80% and 90%: normal wear for a battery a few years old. Expect proportionally shorter runtime.
• Capacity under 80%, or condition “Service Recommended”: the battery still works safely, but a replacement will feel like a new laptop. Apple and authorized providers replace MacBook batteries; check your AppleCare status first.
• Swollen battery signs (trackpad that clicks poorly, a case that rocks on a desk, a gap at the bottom panel): stop charging and get it looked at. That’s not something a health number will tell you.

One cycle is 100% of capacity used, not one plug-in. Using 50% today and 50% tomorrow counts as one cycle.

Slow down the wear

Heat and long stretches at 100% age lithium batteries fastest. Two built-in settings help:

1. Optimized Battery Charging: on by default. It learns your routine and pauses at 80% until you usually unplug.
2. Low Power Mode: System Settings › Battery › Low Power Mode, on battery only or always. Less heat, longer runtime.

Keep the Mac off soft surfaces that block airflow while it charges, and don’t leave it in a hot car. If you want a hard charge limit (for example, stop at 80% every time), that needs a third-party app; see the battery health apps roundup.

To find what’s draining it day to day, the energy column in Activity Monitor is the place to start: which app uses the most energy.

Seeing it live

Stat Space’s Battery tab reads the same AppleSmartBattery values and shows capacity in mAh against design, cycles, condition and temperature, next to live charge, power flow and the charger’s negotiated watts. It keeps a 24-hour and 7-day charge chart, and lists energy by app right now. All of that is free.

It doesn’t set charge limits. If that’s what you’re after, pair it with a dedicated charge-limiting app.