Why batteries age

Phones use lithium-ion or lithium-polymer batteries. Every charge and discharge causes chemical changes in them that gradually reduce their capacity. Manufacturers usually expect the capacity to drop to around 80% of the original after a few hundred charge cycles.

Ageing is greatly accelerated by heat and by spending long periods fully charged. Complete discharge also does harm: a deeply discharged battery can be damaged permanently.

How to make your battery last

  • Don't leave your phone in the heat. A car dashboard in summer, charging under a pillow or demanding games while charging heat the battery the most.
  • You don't need to run it down to zero. Lithium batteries have no memory effect. They are happiest roughly between 20 and 80%.
  • Turn on battery protection. Many phones can stop charging at 80 to 85% or slow it down intelligently overnight. Look in the battery settings for something like Battery protection or Optimised charging.
  • Use a good-quality charger and cable. Cheap unbranded chargers may not deliver a stable voltage and don't always have overheating protection.
  • If you are putting your phone away for a long time, leave the battery about half charged and switch the phone off.

When it is time for a replacement

  • the phone doesn't last a day, although it used to last much longer
  • it switches off at 20 to 30%, or as soon as you go outside in winter
  • the percentage jumps, for example from 40 straight to 10
  • the phone won't switch on unless it is connected to the charger
  • the screen or back cover is lifting and a gap appears between the frame and the cover: that is a swollen battery

Some phones show the battery condition right in the settings. On Samsung phones you will find it in the Samsung Members app under Diagnostics.

Why leave the replacement to a repair shop

In today's phones the battery is glued in, and you can only get to it through the back cover or the screen, which have to be heated and carefully separated. A moment's carelessness is enough to crack the glass, tear the display cable or puncture the battery. A damaged lithium battery can catch fire.

For a battery replacement we use original parts or parts of equivalent quality. We give a 6-month warranty on the work and 24 months on spare parts (for batteries the manufacturer may set a shorter period).

Don't throw the old battery in the bin. It belongs at a collection point or in a battery collection box.