BERLIN: If your phone or laptop's battery level drops suddenly and unexpectedly, you may need to recalibrate your device so it can correctly recognise the battery’s maximum available capacity.
It is normal for a lithium-ion battery to gradually lose capacity over time.
Calibration means adjusting your device to the battery’s current actual capacity. Generally, whether you have an iPhones, iPad or an Android device, the process is pretty similar. Here is how to do it:
- Use your device until you drain the battery enough that it shuts itself off.
- If possible, turn the smartphone or tablet back on and wait again until it shuts off.
- Then charge the device from 0% to 100% while it’s turned off.
- Disconnect the device from the charger and turn it back on. Done.
100% sounds good but isn’t for batteries
Generally speaking, however, charging the battery to 100% isn’t ideal for battery health. It’s best to avoid letting the battery level drop below 20% whenever possible and to only charge it up to 80%.
Since Android 15 at the latest, most Android smartphones have included a Charging Limit feature in the battery settings that automatically caps the power supply at an 80% charge level.
For iPhones, this feature has been available since iOS 14 as Charging Limit under Settings > Battery > Battery Health & Charging.
You need to temporarily disable these settings if you want to calibrate your battery. However, some smartphone models will occasionally charge to 100% on their own even with the limit enabled, meaning they calibrate themselves automatically.
Same applies to laptops
You often find an increasingly inaccurate battery percentage display with laptops that are not brand new anymore. The calibration process is very similar. If you have a Windows device, here's how it works:
- Go to Control Panel > System and Security > Power Options, open the power plan, and under Turn off the display, select the Never setting
- Also select Never under Sleep after
- Then click Advanced power settings, and under Power Options > Battery, select Shut down for Action when battery capacity is critical and set the value to 5% under Critical battery capacity > Battery power.
- Next, fully charge the device and, once it reaches 100 percent, leave the power adapter connected to the computer for another one to two hours.
- Then remove the power adapter and use the device or let it run until it shuts down on its own.
- Finally, plug your power adapter back in, start the device, and charge it to 100%. Done. You can now restore the original individual settings for the power options.
Laptops often have charge limit feature too
Your laptop battery will also benefit from a charging window between 20% and 80%. And there are also models where you can set a charge limit of 80% in the BIOS menu. This makes even more sense the more often the device is permanently connected to the power adapter.
The BIOS menu opens if you hold down the F2, Del, or sometimes F10 key immediately after turning on the computer. If in doubt, do a quick online search to find the key your device manufacturer assigned for this function.
In MacBooks, this feature is called Battery Management and you find it in System Preferences under Battery.
The same applies to laptops. You should disable any charging limits set before calibrating. – dpa
