Battery and charging port test

When to check the battery and charging port

Check them when you look at a used device, when charging cuts in and out or only works with the cable at an angle, when the battery drains unusually fast, and after a battery or charging port replacement. A loose charging port is common on used devices and easy to miss if you only plug in once.

Common faults and their causes

• Charging cuts out when the cable moves: a loose or worn port, or pocket lint packed inside. Often a clean-out is all it needs.
• Fast drain: a worn battery. It can also be an app running in the background or a very bright screen: the Battery section in Settings shows which apps use the most.
• Shutting down at 10 to 20% charge: a sign of a badly worn battery.
• A swollen battery: the screen lifts at the edge, or a laptop touchpad gets stiff. Replace it straight away and stop charging it.

Browsers can't read battery health. Look in Settings › Battery › Battery Health (iPhone), the Battery section or the maker's device care app (Android), or the battery report command on Windows. Details in the battery guide.

What to do if you find a fault

• Try another cable and charger first to rule out the accessories.
• Look into the port with a torch. If there's lint, switch the device off and lift it out gently with a wooden toothpick.
• A battery below about 80% health is usually worth replacing. If you're buying the device, the cost of a new battery is a fair point to raise when you negotiate the price.