Battery Health Explained: What the Percentage Actually Means
You've seen '87% battery health' on refurbished listings — but what does that number really tell you about day-to-day performance and lifespan?
Every refurbished phone listing includes a battery health percentage, and every customer understands it slightly differently. Some assume 87% means the phone will last 87% of a day. Others assume it means the battery is already on its last legs. Neither is right.
Here is what the number actually measures, how it behaves over time, and when you should care.
What the percentage measures
Battery health is simply the current maximum capacity of the battery divided by its original design capacity. A phone that originally held 4,000 mAh and now holds 3,480 mAh reports 87% health.
It does not measure voltage sag, internal resistance, or peak current delivery — though on Apple devices, those factors also trigger warnings below about 80%. It also does not mean the battery will suddenly fail when it reaches any specific number.
How fast it drops
Modern lithium-ion cells lose about 10–15% of their original capacity in the first 500 full charge cycles (roughly 1.5 to 2 years of normal use). After that, the rate slows significantly. A battery reporting 85% at year two will often still report 78–80% at year four if you charge gently.
Heat, fast charging, and consistently charging from 0% to 100% accelerate the curve. Keeping the phone between 20% and 80% slows it down.
When it actually affects your day
Between 100% and 85% health, most people notice nothing. Between 85% and 75% health, you'll lose roughly an hour of screen time versus new. Below 75%, the phone may start throttling peak performance to avoid unexpected shutdowns.
On Apple devices, iOS displays 'Service' when health drops below a threshold (typically around 80%). This is not a fault — it's a cue that a battery replacement would restore peak performance.
What we ship
Wahat Al Tiqniah minimum is 80%. Our Good grade is typically 85%+, and Excellent is 90%+. Every listing shows the exact measured figure. If a battery tests below 80%, we replace it before the device is graded, using genuine or OEM-equivalent cells.
A 90% battery in a refurbished phone will almost always outlast the warranty of a new phone's first-year usage — and if it doesn't, our 12-month warranty covers a free replacement.
