Direct answer
Battery health is a measured remaining capacity, not a grade letter. On iPhone, Apple defines maximum capacity relative to when the battery was new and publishes 80% design points by generation and cycle count. A wholesale quote needs a floor, a reading method, and a rule for replaced batteries.
Key takeaways
- Write a battery floor in the order before you inspect.
- Read the number on the device. A chat message is not a reading.
- Apple’s 80% figures are design targets under ideal conditions, not a reseller law.
- A new-looking phone can sit below 100% before first retail use.
- Android lots need a named method because OS screens vary.
Battery is a lot-level cost. One carton of low-health units becomes a service queue, not a bargain.
What the risk means
Lithium-ion capacity falls as the cell ages. Apple calls the on-device percentage maximum capacity: remaining capacity relative to when the battery was new. Peak performance can fall as well. Cold weather and a low state of charge can make a chemically aged battery look worse for a while.
Apple also notes that time between manufacture and first activation can show slightly under 100%. That is not automatically a swapped cell.
Why bulk buyers should care
- Retail buyers ask for a number.
- A replaced battery can change parts history.
- Shipping and storage abuse does not show in a cosmetic grade.
Accept / Clarify / Reject
| Evidence | Accept | Clarify | Reject |
|---|---|---|---|
| iPhone reading | Settings path used, at or above your floor | “Good battery” only | Far below floor, undisclosed |
| Cycle count | Shown on supported iPhone 15 and later | Not available on the model | Hidden after you asked |
| Replaced battery | Disclosed, history matches | “New if needed” | Secret swap, Unknown part |
| Android lot | Named app or service menu | Mixed methods | No method at all |
How to test it
iPhone. Settings > Battery > Battery Health, or Battery Health & Charging on older models. On iPhone 15 and later with a current iOS, Apple also exposes cycle count, manufacture date, and first-use date.
Apple’s published design notes, under ideal conditions:
- iPhone 14 and earlier: retain 80% at 500 complete cycles
- iPhone 15 and later: retain 80% at 1,000 complete cycles
A complete cycle is not “one overnight charge.” Apple describes it as using an amount equal to 100% of capacity, which can span more than one charge.
Android. There is no single official screen. Record the brand menu or diagnostic you used. Do not invent an iPhone-style percentage if the device does not show one.
What evidence to request
- Floor in the quote, for example “iPhone 85% or above, read on device”
- Sample readings with IMEI
- Disclosure of replacements
- Rule for units that boot-loop or will not charge
Common supplier wording
- “Original battery” with no reading
- “Like new health”
- “We replace below 80%” with no proof after arrival
Related checks
Frequently asked questions
Is 80% the official wholesale cutoff?
No. Apple describes 80% as a design point after a stated cycle count under ideal conditions, and discusses service when capacity is significantly degraded. Your floor is a commercial choice. Write it.
Does a replaced battery make the phone Grade A?
Not by itself. A replacement can restore capacity and still leave Unknown parts, unfinished calibration, or a mismatched cosmetic grade.
Sources and methodology
- iPhone battery and performance — Apple Support Accessed August 22, 2026.
- About the battery and performance of iPhone 11 and later — Apple Support Accessed August 22, 2026.
- Understand your iPhone battery usage and health — Apple Support Accessed August 22, 2026.
- iPhone Parts and Service History — Apple Support Accessed August 22, 2026.
Update history
- — First published. Official sources on this page were accessed on this date unless a later note says otherwise.
Factual corrections after publication are listed on the corrections page. There is no separate reviewer identity on this desk. See the editorial policy.