Battery Health
How to check your laptop battery health, cycle count, and settings to extend its lifespan
Laptop batteries degrade over time. After a few hundred charge cycles, your battery will hold less charge than it did when it was new. Checking your battery health tells you how much capacity is left and whether it is time for a replacement. You can check battery status in your browser at thetest.com/sensors — it reads the Battery API to show your current level and charging state.
Check battery health:
- Open System Settings > Battery
- Click Battery Health (or the i icon next to it)
- You will see Maximum Capacity (a percentage of original capacity) and Condition (Normal or Service Recommended)
- If it says Service Recommended, the battery has degraded significantly and should be replaced
Check cycle count:
- Hold Option and click the Apple menu
- Select System Information
- In the left sidebar under Hardware, click Power
- Under Battery Information > Health Information, look for Cycle Count
Optimized charging:
- Open System Settings > Battery > Battery Health
- Make sure Optimized Battery Charging is turned on — this learns your daily routine and waits to charge past 80% until you need it, reducing wear on the battery
Tips to extend battery life:
- Lower screen brightness — it is the single biggest power draw on a laptop
- Turn off Bluetooth and Wi-Fi when you do not need them
- Close apps you are not using, especially browsers with many tabs
- Use Low Power Mode in System Settings > Battery when you need to stretch battery life
- Avoid leaving your MacBook plugged in at 100% for days at a time — optimized charging helps with this, but unplugging occasionally is still good practice
Frequently Asked Questions
What is a battery cycle count?▾
One cycle is a full discharge of the battery's total capacity — it does not have to happen all at once. If you use 50% one day and 50% the next, that counts as one cycle. Most laptop batteries are designed for 300 to 1000 cycles before they drop below 80% of original capacity. Apple rates MacBook batteries at 1000 cycles, for example.
When should I replace my battery?▾
Replace it when battery health drops below 80% and you notice significantly shorter battery life. If your OS shows a "Service Recommended" or "Consider replacing your battery" message, that is a clear sign. Some people continue using degraded batteries plugged in, but severely degraded batteries can swell and should be replaced promptly.
Should I keep my laptop plugged in all the time?▾
Keeping a laptop at 100% charge constantly puts extra stress on the battery and accelerates wear. Modern laptops with optimized or smart charging handle this better by capping the actual charge level. If your laptop supports it, enable optimized charging and do not worry too much. If it does not, try to unplug occasionally and let the battery discharge to around 40-50% before charging again.
Does battery calibration actually help?▾
No. Battery calibration — fully draining then fully charging — was useful for older nickel-based batteries but does not meaningfully help modern lithium-ion batteries. In fact, deep discharges can slightly increase wear. The battery gauge may occasionally show an inaccurate percentage, but a restart usually fixes that without needing a full discharge cycle.
Why is my battery draining so fast?▾
The most common causes are high screen brightness, background apps consuming power, and an active Bluetooth or Wi-Fi connection you do not need. Open your task manager or activity monitor to check for apps using significant energy. A degraded battery also drains faster because it holds less total charge — check your battery health to rule that out.