A2181 296mAh Replacement Battery for Apple Watch Series 5 / SE 44mm
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Part No.: A2181 | Capacity: 296mAh / 1.129Wh | Voltage: 3.81V | Type: Li-Polymer
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Compatible with Apple Watch Series 5 (44mm) & Apple Watch SE (1st Gen, 44mm) — models A2093, A2095, A2157, A2356, A2354, A2352
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Grade A Li-polymer cells · 0 cycles on arrival · 500+ charge cycle lifespan
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Built-in IC protection: overcharge / over-discharge / short circuit / thermal cutoff
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CE & RoHS certified · factory-tested before shipment
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MOQ: 50 pcs · Bulk pricing available · Sample orders accepted · Ships within 3–5 business days
Product Description
The A2181 is the OEM battery model number for Apple Watch Series 5 (44mm) and Apple Watch SE 1st Generation (44mm). At Balder Power, we manufacture this Li-polymer cell to the exact OEM specification: 296mAh rated capacity, 3.81V nominal voltage, 1.129Wh energy output — no inflated figures, no counterfeit cells.
This battery is widely used by watch repair shops, refurbishers, and electronics distributors across North America, Europe, and Australia. Our production line runs ISO-controlled Grade A cells with zero compromise on consistency across bulk orders.
Verified Compatible Models (P/N Cross-Reference):
| Device | Watch Model Number | Battery P/N |
|---|---|---|
| Apple Watch Series 5 44mm | A2093 / A2095 / A2157 | A2181 |
| Apple Watch SE 1st Gen 44mm | A2352 / A2354 / A2356 | A2181 |
⚠️ Not compatible with: Series 5 40mm (uses A2277), Series 6 44mm (uses A2327), or SE 2nd Gen.
Technical Parameters
| Parameter | Specification |
|---|---|
| Part Number | A2181 |
| Rated Capacity | 296 mAh |
| Actual Capacity | 296 mAh |
| Nominal Voltage | 3.81 V |
| Energy | 1.129 Wh |
| Battery Type | Li-Polymer (Lithium Polymer) |
| Charge Cutoff Voltage | 4.2 V |
| Discharge Cutoff Voltage | 2.75 V |
| Cycle Life | ≥500 cycles @ ≥80% capacity retention |
| Compatible Devices | Apple Watch Series 5 44mm (A2093/A2095/A2157) · Apple Watch SE 1st Gen 44mm (A2352/A2354/A2356) |
| Protection Circuit | Overcharge / Over-discharge / Short Circuit / Thermal |
| Certifications | CE · RoHS · UN38.3 |
| Operating Temperature | Charge: 0°C ~ 45°C · Discharge: -20°C ~ 60°C |
| Storage Temperature | -20°C ~ 35°C (recommended at 40–60% charge) |
| Shelf Life | 6 months (standard conditions) |
| MOQ | 50 pcs (samples available) |
| Lead Time | 3–5 business days (in-stock); 10–15 days (custom lot) |
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
✅ Exact OEM Specification — No Oversell
Rated and actual capacity are both 296mAh. We do not market “upgraded” or “enhanced” capacity — a cell forced beyond spec degrades faster and can trigger BMS rejection on watchOS. What you receive matches what the original Apple hardware expects.
✅ Grade A Li-Polymer Cells, 0 Cycles on Arrival
Every unit ships with zero charge cycles logged. Cells are sourced from our verified upstream suppliers and pass incoming QC before entering our assembly line. Shelf life: 6 months at 40–60% charge in ambient storage.
✅ Built-In Multi-Layer IC Protection
Integrated protection circuit covers: overcharge (>4.2V cutoff), over-discharge (<2.75V cutoff), short circuit, and thermal runaway prevention. This IC mirrors the original Apple BMS handshake protocol — no “not charging” errors on watchOS.
✅ CE & RoHS Certified — Ready for EU / US Market Distribution
Certification documentation available upon request. Suitable for import by repair distributors in the EU, UK, US, and AU without additional compliance steps for the battery component itself.
✅ 500+ Cycle Lifespan at ≥80% Retained Capacity
Tested per IEC 61960 standard. Under normal use conditions (daily charge, ambient temperature 15–35°C), the cell retains above 80% capacity after 500 full charge/discharge cycles.
✅ B2B Bulk Supply with Consistent Lot-to-Lot Uniformity
Each production lot is batch-tested for capacity variance (<±3%). For repair shop operators or refurbishment lines handling high volume, this matters — inconsistent cells cause rework. We provide lot test reports on request for orders above 200 pcs.
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.
Beyond OEM Standards: Engineered for the Entire Apple Ecosystem
With 10+ years in lithium battery production, 1,600+ standard & custom models, and shipments to 40+ countries, Balder Power build replacement batteries with consistent performance—ready for wholesale and OEM supply.
True High-Capacity Cells
Adopts 100% Pure Cobalt (LiCoO2) chemistry across all lines. Delivers 20%-30% higher energy density than standard OEM batteries, extending daily usage for iPhones, iPads, and Watches alike.
Premium TI IC Solution
Powered by original Texas Instruments (TI) Gas Gauge ICs. Ensures accurate battery percentage display, prevents sudden shutdowns, and supports Zero Pop-up errors (via BMS transplant) for newer iPhone models.
800+ Cycle Life & 100% Healthability
Engineered for longevity with 800+ charging cycles (vs. industry standard 500). Guaranteed 0-Cycle brand-new cells showing 100% Battery Health immediately after installation on all devices.
All-Weather Reliability
Specialized electrolyte formula ensures stability from -10°C to 50°C. Prevents "winter shutdowns" for iPhones/Watches and maintains stable voltage output for iPads in extreme climates.
Anti-Swelling Safety Tech
Uses premium aluminum-plastic film packaging and optimized electrolytes to suppress gas generation. Critical for protecting large iPad screens and delicate Watch displays from pressure damage and swelling.
1:1 Precision Original Fit
From laser-cut Watch cells to precision-molded iPad batteries, we guarantee Zero Thickness Deviation. Ensures perfect connector alignment and a flush screen fit, eliminating "screen lift" or pressure spots.
Factory-Direct OEM Services
One-stop supply chain for all Apple series. We support Mixed Low MOQ orders (e.g., iPhone + Watch + iPad combo), custom private labeling, and retail packaging for global distributors.
Industry-Leading Warranty
Strict QC protocols keep our RMA rate below 0.1%. Every battery—whether for a tiny Watch or a large iPad Pro—is backed by our comprehensive 13-Month Warranty for your peace of mind.
Factory Experience & Quality Control (Built for Bulk Supply)
We understand that B2B buyers care most about consistency and delivery stability. As your dedicated Apple ecosystem battery manufacturer in China, our production workflow implements a unified quality standard across all device categories—from high-precision Apple Watch cells to high-capacity iPad packs.
We perform rigorous 72-hour aging tests on every battery series to ensure reliable performance for wholesale replacement markets and OEM projects. Whether you are sourcing a mixed order of 50 units or a container of 5,000, our ISO-certified process guarantees that every single battery is a Zero Cycle unit ready for immediate installation.
Our lithium battery certifications
FAQ
Q1: Is the A2181 battery compatible with both Apple Watch Series 5 44mm and SE 44mm?
Yes. The A2181 part number covers both Apple Watch Series 5 44mm (models A2093, A2095, A2157) and Apple Watch SE 1st Generation 44mm (models A2352, A2354, A2356). It is not compatible with Series 5 40mm, Series 6, Series 7, or SE 2nd Gen — those use different part numbers. Always verify the model number engraved on the watch case back before ordering.
Q2: Does the A2181 battery need to be activated or calibrated after installation?
No special activation is needed. However, for optimal capacity accuracy and battery health reporting in watchOS, we recommend running 2–3 full charge/discharge cycles after installation. Charge to 100%, use until the watch shuts off, then charge back to 100%. This calibrates the BMS and gives accurate battery percentage readings.
Q3: How long does this battery typically last before needing replacement?
Under normal daily use — approximately 18 hours active use per day with standard charging — the cell retains above 80% of its original 296mAh capacity for 500+ charge cycles. That typically translates to 2–3 years of real-world service. Exposure to high heat (above 35°C ambient) or frequent partial charging accelerates degradation.
Q4: What is the minimum order quantity (MOQ) and do you offer samples?
Our standard MOQ is 50 pcs per model. Sample orders (typically 2–5 pcs) are accepted for qualified buyers — contact us with your company details and intended use case. Sample lead time is 2–3 business days. Bulk orders above 500 pcs qualify for tiered pricing; request a quote via the form above.
Q5: What certifications does this battery carry, and is it safe to import into the EU or US?
The A2181 battery holds CE, RoHS, and UN38.3 certifications. UN38.3 is the mandatory transportation safety standard for lithium batteries shipped by air or sea. CE covers EU market compliance. RoHS confirms restriction of hazardous substances. Full certificate documentation is available as PDF upon request with your order confirmation.
Q6: What is the warranty, and how do you handle defective units in bulk shipments?
We provide a 12-month warranty from the date of shipment against manufacturing defects (capacity below spec, IC failure, physical defect at arrival). For bulk orders, we include 1–2% overage stock at no charge to cover any DOA units. For defect rates above 2%, we arrange replacement or credit — no need to return the full batch. Inspection video or photo documentation is sufficient for warranty claims.
