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Buying Guide

Check battery health before buying a used phone

5 min read

The battery is the component that degrades most with use, and the hidden cost buyers overlook most often when shopping second-hand.

Batteries degrade by charge cycles, not purely by age. Two phones of identical age can have very different battery health depending on how the previous owner used them.

Benchmarks worth holding to

Acceptable battery health
80% or above

for everyday use

Negotiate the price
below 80%

to cover a replacement

Average cycles per year
~350

typical user

What to ask the seller for

  • A screenshot of battery health from the settings menu
  • Whether the battery was replaced, and whether at an authorised centre
  • A live charging test — it should charge normally without unusual heat