Battery health: what a percentage really tells you

Battery condition is one of the biggest variables in refurbished phones and laptops. A headline price can stop being attractive if the battery needs replacement shortly after purchase.

For phones

Prefer sellers that state a minimum battery capacity or allow a new-battery option. Compare the price difference with the cost and inconvenience of replacing the battery later.

For laptops

Ask for design capacity versus full-charge capacity when possible. Runtime claims are useful only when the test conditions are stated. Also verify whether the battery is covered by the seller's warranty.

Do not over-read one number

Battery health is important, but it is not the entire device. Screen condition, charging ports, thermal behaviour and warranty still matter.