Glossary → Battery & Power Terms
What Is Battery Health?
The percentage showing how much charge capacity your battery retains versus when it was new.
Definition: Battery health is a percentage showing how much charge capacity your battery retains compared to when it was new. A new battery starts at 100%. Each charge cycle causes a small, permanent drop. Below 80% means significant degradation — and on iPhones, triggers CPU throttling that makes the phone feel slow.
How to check battery health
iPhone: Settings → Battery → Battery Health & Charging. Replace at 80% or below.
Samsung: Dial *#0228# or use Samsung Members app → Interactive checks → Battery status.
Other Android: Use AccuBattery app (free) to measure real charge capacity vs design capacity over a few charge cycles.
Why Singapore’s climate matters
Heat is a lithium-ion battery’s main enemy. Singapore’s 30–34°C daily temperatures accelerate degradation significantly compared to temperate climates. A phone used in Singapore for 18 months may reach 80% health — a phone in Europe typically takes 2–3 years. Leaving your phone in a car (which can reach 60–70°C interior) causes irreversible capacity loss in a single exposure.
Related terms
→ Battery Cycle — how charge cycles accumulate and drive health decline
→ Power IC — chip failure can mimic battery health problems
→ Charging Port — sometimes mistaken for a battery issue
→ Activation Lock — check this if buying a second-hand iPhone for battery replacement
Battery health below 80% or phone dying fast?
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