Phone battery: capacity, battery life and care
A battery is the rechargeable power source in a phone, tablet, watch or laptop. Its capacity is measured in mAh or Wh, and real battery life also depends on the screen, chip and software optimisation.
In plain words
A battery is like a car's fuel tank. Capacity is the size of the tank, and battery life is how far you can drive. Two cars with the same tank go different distances: one is economical, the other a "guzzler". Phones are the same: 5000 mAh lasts two days in one and only one day in another.
How it works
- Modern devices use lithium-ion or lithium-polymer batteries.
- A power controller monitors charge and temperature and prevents overcharging.
- Capacity gradually decreases with every charge cycle and with age.
- Fast charging delivers more power but also heats the battery more.
- The system shows the charge percentage and battery health in settings.
Where you'll see it
In specs: "5000 mAh battery", "45 W fast charging", "15 W wireless". In our comparisons, the Battery row. For battery life, reviews and tests are more accurate.
Does it matter when buying
Yes, battery life is one of the most important specs. Compare not just mAh but also battery-life tests. For power outages, phones with a big battery and reverse charging are handy. And to help your battery live longer, avoid heat and turn on optimised charging.
Myths
- Myth: The more mAh, the longer the phone lasts. Reality: A lot depends on how efficient the chip and screen are.
- Myth: You need to "break in" a battery with full cycles. Reality: Lithium batteries do not need this, and it can even harm them.
FAQ
How do I check battery health?
On iPhone: Settings - Battery; on Android: in the battery settings or service menus.
When should I replace the battery?
When capacity has dropped below about 80% and the phone drains noticeably faster.
Can I replace the battery myself?
Better at a service centre: batteries are glued in and can be dangerous if damaged.
Related terms
Lithium-ion battery, mAh and Wh, Charge cycles and battery wear, Optimised charging (80% limit), Silicon-carbon battery