The 7 Plus and 8 Plus batteries are nearly identical at a glance — same shape, same connector, same voltage — and the temptation is to treat them as interchangeable. Almost anything that fits mechanically, but the cell capacities and thickness differ in ways that change the repair outcome.
Comparison table
| Spec | iPhone 7 Plus | iPhone 8 Plus |
|---|---|---|
| Capacity | 2900 mAh | 2691 mAh |
| Watt-hour rating | 11.10 Wh | 10.28 Wh |
| Cell thickness | ~4.5 mm | ~4.0 mm |
| Connector | B2B single-row | Same single-row, same pin count |
| BMS pairing requirement | Standard | Standard, same generation |
| Wireless charging | No | Yes (board feature, not battery) |
What you can and cannot do
- Can swap: connector, board-side mating, adhesive strips
- Cross-fit a 7 Plus cell into an 8 Plus: not advisable — the cell is thicker than the original; you cannot seat the screen flat
- Cross-fit an 8 Plus cell into a 7 Plus: works mechanically, the screen closes, capacity is reduced ~7% — but BMS pairing may trigger a warning on later iOS versions
- Use aftermarket cell of either spec: yes, with original-spec matched BMS to avoid the "Unable to verify" warning
Why this matters in practice
Cell thickness differences become apparent only when you close the phone: the screen sits 0.5 mm too high and creaks at one corner, or the adhesive does not seat. Forcing the screen onto an over-thick cell cracks the LCD backlight filter and you create a new fault while fixing the old one. Match by model, every time.
Stocking rule
Two SKUs: one for 7 Plus, one for 8 Plus. Both available in the battery collection with verified BMS chips. Browse the 7 Plus range or 8 Plus range for surrounding parts. Wholesale lots on either SKU ship same-day from Shenzhen with DHL.
FAQ
Are the X / XS / XR batteries interchangeable? No, each generation has a unique footprint, connector position, and BMS pairing logic. The Plus-generation comparison above is a special-case closeness, not a general rule.
Best MOQ on the 7 / 8 Plus batteries for a new shop? 10 pieces per model for the first trial — enough to evaluate two cells per unit on average.