Apple and Samsung advise 80% charge limit to extend smartphone battery life

Smartphone manufacturers Apple and Samsung have introduced built‑in settings that stop charging once the battery reaches about 80 % of its capacity. The feature aims to lessen chemical stress and heat generation in lithium‑ion cells, which accelerates capacity loss when the last 20 % of charge is forced.

Activating the limit on iPhones running iOS 26.5 involves Battery → Battery Health → Optimized Charging, while Samsung devices on One UI 8 use Settings → Device Care → Battery → Battery Protection, offering both a basic 100 % stop‑and‑resume mode and an advanced 80 % cap. Users who keep phones plugged in for extended periods, especially overnight or while using fast‑charging, are advised to enable the 80 % limit to potentially double battery lifespan.