Battery health explained: what 85% really means
Battery health is the number that matters most on a used phone. We explain what it measures and how long it will last.
Lithium-ion batteries slowly lose capacity every time they are charged. Battery health compares today's maximum capacity with the capacity when the phone was new.
What the numbers mean
- 95–100%: practically new, full-day battery life
- 85–94%: very good, you will hardly notice a difference
- 80–84%: noticeable, may need a top-up in the evening
- Below 80%: a battery replacement is recommended
How to make it last
Avoid leaving your phone at 100% on the charger overnight in a hot room, and try not to drain it to 0% regularly. Most modern phones have an optimised charging option — turn it on.
We list the exact battery health of every phone in our store, so there are no surprises.
