Batteries
How to identify original batteries (and spot the rewraps)
5 min readUpdated Aug 11, 2026
Batteries are where the wholesale market is least honest. "Original" gets printed on wraps that cover pulled, recelled or generic cells, and the customer only finds out three months later when the phone dies at 40%.
These are the checks a tech can run in under two minutes, before the part ever goes into a customer's device.
Read the cell, not the wrap
Anyone can print a wrap. The information that matters is on the cell itself and in the data the phone reports on first boot.
- Cell manufacturer code: genuine cells are made by a short list of makers (Sunwoda, Desay, Simplo, ATL, Samsung SDI, LG). A blank or generic code is a rewrap.
- Date code: an original-capacity cell that was manufactured five years ago is a pull, not new stock, and will already have lost capacity on the shelf.
- Batch and serial consistency: on a genuine batch, codes increment sensibly. Identical serials across ten units means printed labels.
- Weight: recelled batteries are frequently lighter than spec because a smaller cell was fitted inside the original shell.
Be suspicious of inflated capacity
A replacement advertised well above the factory mAh rating is the clearest red flag in the category. The physical volume inside the phone has not changed, so a genuinely higher-capacity cell in the same footprint is chemistry that does not exist at commodity prices.
In practice, high-capacity claims come from either an inflated printed number or a cell packed past safe tolerance — which is a swelling and thermal risk, not a feature.
| Claim on the wrap | What it usually means |
|---|---|
| Within ±3% of factory mAh | Credible — normal manufacturing spread |
| +10% to +25% "high capacity" | Inflated marketing number or an over-packed cell |
| No mAh printed at all | Unknown cell — treat as generic |
| "Original pull, 100% health" | Used cell; verify cycle count before fitting |
Verify on the bench in two minutes
Fit the battery, boot the device and read the data before you close the phone. Everything below is visible without extra hardware apart from a battery tester.
- Cycle count on first boot should be 0–2. Anything higher is a used or previously fitted cell.
- Reported design capacity should match the factory figure for that model.
- Charge a sample from 20% and watch for abnormal heat — a good cell warms, it does not get uncomfortable to hold.
- Inspect the connector: crisp gold-tone contacts and a clean flex fold. Dull, pitted or reflowed pads mean the flex was salvaged.
- Check the pouch is flat. Any pillowing out of the box is an immediate reject.
What to tell the customer
Battery health warnings on iPhone appear with any non-Apple-serialized cell, including genuine Apple parts that were not paired. Say this at intake rather than after the repair, and note it on the ticket — it removes the most common post-battery-repair dispute.