Apple Watch Series 8 Battery A2961 / A2810 | 3.86V 41mm 282mAh & 45mm 308mAh — Temperature Sensor Compatible
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✅ Fits Apple Watch Series 8 (41mm & 45mm) — P/N A2961 (41mm, 282mAh) and A2810 (45mm, 308mAh); 3.86V; covers A2473, A2474, A2475, A2476 (41mm) / A2431, A2432, A2433, A2434 (45mm)
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✅ First Watch generation with wrist temperature sensor and Crash Detection — both features preserved post-replacement with correctly spec’d cell
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✅ ±0.1mm dimensional tolerance — OLED-safe installation; 3.86V PCM specific to S8, not interchangeable with S6 (3.85V) or S5/SE (3.82V)
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✅ Factory direct — both size variants in stock; custom labeling from 200 pcs; 12-month warranty; DOA < 0.3%
Product Description
The Apple Watch Series 8 (2022) introduced two features that were firsts for the Apple Watch lineup: a wrist temperature sensor (sampling every 5 seconds during sleep for ovulation cycle tracking) and Crash Detection (using the high-g accelerometer to detect vehicle collisions and automatically contact emergency services). Both run as continuous or event-driven background processes that draw from the battery without user interaction. A degraded or sub-capacity replacement cell affects background sensor reliability before it noticeably affects screen-on time — which is why S8 battery quality has a direct functional dimension beyond just runtime.
Battery P/N is A2961 for the 41mm case (282mAh) and A2810 for the 45mm case (308mAh). Both run at 3.86V nominal — the same voltage profile as Series 9, but on different P/Ns with generation-specific connector seating. The 3.86V PCM is distinct from Series 6 (3.85V) and Series 5/SE (3.82V). These are not interchangeable.
Verified Compatible Models:
| Device | Size | Apple Model IDs | Battery P/N | Capacity |
|---|---|---|---|---|
| Apple Watch Series 8 | 41mm | A2473, A2474, A2475, A2476 | A2961 | 282mAh |
| Apple Watch Series 8 | 45mm | A2431, A2432, A2433, A2434 | A2810 | 308mAh |
⚠️ Not compatible with Apple Watch Series 9 (uses A2954/A3009, different P/Ns) or Series 7 (A2473 overlaps as model ID — verify Watch generation, not just model number). Always check the Watch generation alongside the model number on the back housing.
Technical Parameters
| Parameter | 41mm (A2961) | 45mm (A2810) |
|---|---|---|
| Battery P/N | A2961 | A2810 |
| Compatible Models | A2473, A2474, A2475, A2476 | A2431, A2432, A2433, A2434 |
| Nominal Voltage | 3.86V | 3.86V |
| Capacity | 282mAh | 308mAh |
| Cell Type | Li-ion Polymer soft-pack (Grade A) | |
| Dimensional Tolerance | ±0.1mm (OLED re-seating, IP6X/50m water resistance) | |
| PCM Spec | 3.86V — NOT interchangeable with S6 (3.85V) or S5/SE (3.82V) | |
| Charge Voltage (Max) | 4.35V ± 0.05V | |
| Discharge Cut-off | 2.75V | |
| Feature Compatibility | Wrist temp sensor, Crash Detection, AOD, SpO2, ECG, heart rate | |
| Device Water Resistance | IP6X dust / 50m — maintained with correct cell spec and re-seal | |
| Cycle Life | ≥ 600 cycles @ 80% DOD | |
| Operating Temperature | 0°C ~ 45°C (charge) / -20°C ~ 60°C (discharge) | |
| Connector Type | OEM-compatible flex connector | |
| Protection (PCM) | Overcharge / over-discharge / short circuit / over-current | |
| Certifications | CE, FCC, RoHS, UN38.3; MSDS/SDS on request | |
| OEM/ODM | Custom label / packaging from 200 pcs per variant | |
| Condition | Brand new, 0 cycle, 100% capacity-tested | |
| Warranty | 12 months from shipment date | |
| Lead Time (Stock) | 3–5 business days | |
Need a stable supply plan? Send your model list + quantities + destination. We’ll confirm lead time, shipping method, and compliance documents before you place the order.
Features & Advantages
✅ 🌡️ Wrist Temperature Sensor — Continuous Background Sampling Requires Stable Low-Current Delivery
The S8 temperature sensor samples skin temperature every 5 seconds during sleep tracking. This is a low-current continuous draw — small per sample, but accumulative across an 8-hour sleep session. A cell with elevated internal resistance causes micro-voltage sag during each sample, producing temperature reading gaps or discontinuous overnight data. Grade-A cells with low internal resistance maintain consistent delivery across the full sleep tracking window.
✅ 🚗 Crash Detection — Peak-Current Event Load
Crash Detection activates the high-g accelerometer, GPS, and cellular modem simultaneously to locate the device and place an emergency call. This is one of the highest peak-current draws the Watch experiences. A sub-grade cell with high internal resistance will cause voltage collapse under this simultaneous load — potentially preventing the emergency call from completing. Our cells are rated to handle the S8’s peak current profile without voltage drop below the modem’s minimum operating threshold.
✅ ⚡ 3.86V PCM — S8-Specific, Verified Against Generation
Series 8 runs at 3.86V nominal. Our cells carry PCM calibrated to the S8’s charge profile — overcharge cutoff verified at 4.35V. Despite sharing the same voltage spec as Series 9, the P/Ns are different and the connector seating positions differ by generation. We ship generation-matched cells, not generic 3.86V Watch batteries shared across S8 and S9.
✅ 📐 ±0.1mm Tolerance — Aluminum Enclosure, OLED Re-Seating Critical
Series 8 uses the same case geometry as S7 — larger display, tighter internal clearance than S5/S6. An out-of-tolerance cell prevents OLED re-seating and compromises the IP6X / 50m water resistance seal. Dimensional control is verified on finished cells before shipment, not just on production-line samples.
✅ 🏭 Both Variants in Stock — OEM Options for Watch Repair Distributors
A2961 (41mm) and A2810 (45mm) are stocked and available in a single order. Series 8 is now 2.5+ years old and entering peak replacement demand — units from the launch cohort have completed 900+ charge cycles under daily use. Custom labeling and retail packaging from 200 pcs per variant.
Packing & Delivery
Lead Time & Shipping
In-stock items: Ship within 3 days
For standard replacement models with available inventory.Mass production orders: Ship within 7 days
For regular models under confirmed specifications and packaging requirements.Customized orders: Ship within 15 days
For custom cell configuration, size, wire/connector, PCB/BMS, labeling, or packaging.
Note: Final dispatch time depends on total quantity, model complexity, packaging requirements, and shipping compliance documents. We will confirm the estimated shipping date (ETD) after order confirmation.
Air freight (urgent, smaller volume)
Sea freight (cost-effective for bulk)
Rail / Truck (subject to destination)
Express channels
Documents available: UN38.3 / MSDS / Transport Test Report (if applicable)
Compliant packaging and carton labeling can be arranged based on the chosen shipping method.
EXW / FOB / CIF / DDP available
One-Stop Sourcing for the Complete Apple Ecosystem
-Streamline your supply chain. Consolidate your MacBook, iPad, iPhone, and Watch battery orders into a single shipment to reduce logistics costs and maximize your wholesale margins.
FAQ
Q1: Which Apple Watch Series 8 models do A2961 and A2810 fit?
A: A2961 (282mAh, 41mm) fits A2473, A2474, A2475, and A2476. A2810 (308mAh, 45mm) fits A2431, A2432, A2433, and A2434. Note: A2473 appears as a model ID in both S7 and S8 — always verify the Watch generation, not just the model number. Not compatible with Series 9 (A2954/A3009) or Series 7 despite case size overlap.
Q2: Will the wrist temperature sensor work correctly after replacing the Series 8 battery?
A: Yes, when the replacement cell delivers stable low-current output. The temperature sensor samples every 5 seconds during sleep tracking — a continuous low-level draw across the full sleep window. A cell with elevated internal resistance produces micro-voltage sag during each sample, resulting in data gaps in the overnight temperature log. This shows up as missing readings in the Health app cycle tracking data. Grade-A cells with low internal resistance maintain consistent delivery. No watchOS recalibration is required after replacement.
Q3: Does Crash Detection still function after a Series 8 battery replacement?
A: Yes — when the battery handles peak current correctly. Crash Detection simultaneously activates the high-g accelerometer, GPS lock, and cellular modem to place an emergency call. This is the highest peak-current event the Watch experiences. A sub-grade cell with high internal resistance collapses voltage under simultaneous multi-component load, potentially preventing the cellular call from completing. Our cells are rated to the S8’s peak current profile. The feature requires no recalibration post-replacement.
Q4: Are the Series 8 and Series 9 batteries interchangeable — they have the same voltage?
A: No. Both run at 3.86V nominal, but S8 and S9 use different battery P/Ns (A2961/A2810 for S8 vs A2954/A3009 for S9) with different physical dimensions and connector seating positions. Using an S9 cell in an S8 (or vice versa) results in fitment failure or incorrect connector engagement. The shared voltage spec does not make them substitutable.
Q5: How long does a Series 8 battery last after replacement?
A: Apple’s published battery life for Series 8 is 18 hours under typical use with AOD on, or 36 hours in Low Power Mode. A correctly installed 282mAh (41mm) or 308mAh (45mm) replacement cell restores runtime to those figures. Temperature sensor and AOD are both continuous background loads — they are already factored into Apple’s 18-hour spec, not additional draws on top of it.
Q6: Series 8 is now 2.5 years old — is there still active repair demand, and how does it compare to S9?
A: Yes, and it’s currently at peak. Units from the September 2022 launch cohort have completed 900+ charge cycles under daily use — well past the 600-cycle threshold where capacity drops below 80%. S8 demand is slightly behind S9 in terms of urgency per unit, but the S8 install base is large and the replacement window is now open across the full cohort. For repair distributors, S8 and S9 should be stocked in parallel — they cover adjacent replacement cycles in the same customer base.
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