iPhone Battery Health: What B2B Buyers Need to Know
Battery health is the most-discussed number in the used-iPhone trade — and the most misunderstood. It decides refurbishment cost, end-customer satisfaction and, in some cases, whether a lot is worth its price at all.
This guide explains what the percentage actually measures, which thresholds matter commercially, and how professional buyers factor batteries into a lot calculation.
What the percentage actually means
iOS reports "Maximum Capacity" — the battery's current full-charge capacity relative to its capacity when new. A phone at 85% holds 85% of its original charge. The number says nothing about charging speed defects, swelling or peak-performance throttling, which is why serious traders test beyond the settings screen.
Apple considers a battery worn below 80%; iOS may then flag "Service". Commercially, that 80% line is the hard floor for consumer resale in most markets.
Thresholds that matter in trading
Retail-ready programs typically demand 85%+ so devices survive a warranty period without battery complaints. Refurbishers calculate differently: below 80% means a guaranteed swap, 80–85% is a judgment call, above 90% sells as a feature.
A serious wholesale offer states the battery policy per lot: the minimum threshold, the measured distribution, or per-IMEI reports. If a seller cannot state it, you are buying the risk blind.
Calculating battery cost into a lot
The math is simple: estimated swap quota × (battery part + labor) added to the per-unit price. On models like the iPhone 11–13 a swap runs materially cheaper than on Pro models with higher teardown effort — which is why battery distribution shifts lot value more on Pro stock.
Our lots state battery policies upfront, and per-IMEI health reports are available on request — so this calculation happens before the purchase, not after.
Frequently Asked Questions
Is 100% battery health realistic in used stock?
Only in near-new returns or after a battery swap. In honest used lots the bulk sits between 80–95% — distributions skewing higher usually mean younger devices.
Does battery health drop faster after 80%?
Degradation is roughly linear with charge cycles, but user-perceived runtime problems accelerate below 80% — hence the commercial cutoff.
Are third-party batteries a problem?
iOS flags non-genuine batteries and may hide the health percentage entirely. Professional grading identifies these units — in our stock they are declared.
What battery policy does TR Vertriebs offer?
Policy is stated per lot: minimum thresholds and, on request, per-IMEI battery reports at time of testing.