3S 21700 Lithium-Ion Battery Pack Manufacturer In China
Welcome to Hanery’s dedicated hub for custom 11.1V (3S) 21700 battery packs. We merge the robust 11.1V power platform with the unmatched energy density of 21700 cells. By significantly reducing the required cell count compared to legacy 18650 packs, we engineer 3S power solutions that are more compact, inherently more reliable, and capable of unleashing massive sustained power for your most demanding professional equipment.
Voltage Range: 11.1V
Capacity: 3000mAh to 10,000mAh+
Discharge Rate: 1C to 10C (High-discharge available)
Certifications: UN38.3, MSDS, CE, RoHS, UL.
Safety
Low Self-Discharge
Long Lifespan
Reliability
11.1V 3S 21700 Li-ion Battery Pack Supplier In China
Hanery is your specialist B2B supplier for custom-engineered 11.1V (3S) 21700 battery packs. The 11.1V platform is a critical threshold for devices requiring substantial torque and sustained high speed. When you combine this demanding voltage requirement with the superior energy density of the 21700 format, you unlock a new level of performance and design freedom.
Relying on older 18650 technology for high-capacity 11.1V systems often results in bulky, heavy packs (like a 3S3P or 3S4P) with complex internal wiring. Our 3S 21700 packs offer an elegant, modern alternative: more power and capacity per cubic millimeter. As your direct manufacturing partner, we meticulously select the optimal 21700 cell, design industrial-grade balancing BMS solutions, and utilize robust pure-nickel spot welding. The result is a highly efficient, space-optimized 11.1V power system that elevates your professional drones, power tools, and medical devices above the competition.
Wholesale 3S 21700 Lithium-Ion Battery Packs From Hanery
Is Your High-Performance Device Weighed Down by a Bulky 11.1V Battery Pack?
Shed the excess weight and complexity. Upgrade to a high-density 3S 21700 platform. Achieve the massive power and endurance your device demands, with a significantly smaller footprint.
Any Industries Hanery Served By Custom 3S 21700 Batteries
The formidable 11.1V power delivery and the space-saving architecture of 3S 21700 packs make them essential for heavy-duty, high-drain, and performance-critical applications:
Commercial Drones & FPV UAVs
Providing the high voltage (11.1V) and massive discharge (High-C) required for heavy-lift aerial photography, agricultural spraying, and high-speed racing, all while minimizing critical flight weight.
Portable PA Systems & High-End Audio
Driving high-wattage amplifiers for powerful, distortion-free sound in large portable speakers without making the unit uncomfortably heavy.
Advanced Medical Devices
The reliable, high-capacity 11.1V source for portable oxygen concentrators, surgical tools, and motorized patient lifts that demand all-day operation.
Professional Power Tools
Driving the high-torque motors in professional-grade impact wrenches, large circular saws, and heavy-duty rotary hammers where sustained 11.1V power is required without excessive bulk.
Robotics & AGVs
Providing the sustained torque needed for automated guided vehicles navigating factory floors, benefiting from the simplified, reliable 21700 pack structure.
High-Performance RC Hobbies
The go-to, high-endurance power source for fast RC cars, large-scale model airplanes, and performance boats.
Customized Your 3S 21700 Batteries From Chinese Manufacturer
We transform premium 21700 cells into robust, high-voltage power systems:
Architecture Optimization
We analyze your current 18650 11.1V design and propose a streamlined 21700 alternative (e.g., replacing a 3S3P 18650 with a much lighter 3S2P 21700) for superior efficiency.
Premium Cell Selection
We source top-tier 21700 cells (optimizing for high capacity up to 5000mAh, or high continuous discharge) to perfectly match your motor's torque profile and runtime goals.
Sophisticated 3-Node BMS Integration
Safety is paramount at 11.1V. Our advanced BMS provides precise 3-cell active/passive balancing, deep thermal monitoring, and extreme over-current protection tailored to the higher energy throughput of 21700 cells.
High-Current Architecture
For demanding tools and high-performance drones, we utilize heavy-gauge silicone wiring (e.g., 10AWG/12AWG) and thick pure nickel spot-welding to handle massive amp draws safely.
Advanced Thermal Management
The larger 21700 architecture is carefully designed with cell spacing, specialized cell holders, and robust materials to aggressively dissipate heat during intense, continuous operation.
Custom Geometries & Enclosures
The cylindrical format allows for flexible layouts. We can configure the 3 or 6+ cells into triangles, long sticks, flat arrays, or custom blocks to perfectly integrate into your product's aerodynamic or space-constrained chassis.
Get Your Batteries in Bulk, Step-by-Step
Consultation & Load Profiling
We start by deeply analyzing your application's power demands (continuous/peak Amps, stall torque), target voltage (11.1V), capacity (Ah), and strict physical/thermal constraints.
Pack Engineering & Proposal
Our engineering team provides a detailed proposal showcasing the space/weight savings of the 21700 platform, along with a pack schematic, thermal management strategy, 3D models, and a transparent wholesale quote.
Prototyping & System Validation
We deliver functional, high-power pre-production samples for your rigorous testing and system integration validation under heavy load.
Refinement & Final Approval
We incorporate your feedback, finalize the BMS programming, and lock in the design before scaling up.
High-Volume Pack Assembly
Your bulk order is produced with exceptional consistency on our dedicated, automated pack assembly lines.
Global Logistics & Compliant Delivery
We manage the entire, often complex, compliant shipping process (UN38.3, UL, IEC) for high-energy batteries to your global locations.
6 Benefits From Your Battery Manufacturer
Next-Gen Power-to-Weight Ratio
Leverage the 21700's superior capacity to dramatically increase your 11.1V product's runtime without the severe weight penalty of large 18650 arrays, crucial for drones and portable tools.
Simplified, More Reliable Architecture
Fewer cells in parallel (e.g., a 3S2P 21700 instead of a 3S3P 18650) mean fewer spot welds, a simpler BMS, and a statistically lower risk of failure, enhancing overall pack robustness.
Unleashed Peak Performance
The 21700 format inherently supports robust internal construction. We pair high-discharge cells with heavy-duty busbars to deliver massive continuous power (11.1V) for high-torque motors without excessive voltage sag.
Expert Thermal Management
High-power 3S packs generate significant heat. We engineer custom cell holders, optimized spacing, and robust BMS protections to ensure your 21700 pack runs cool and safe under heavy, continuous loads.
Precision 3-Node Cell Balancing
Safety at 11.1V is non-negotiable. Our sophisticated BMS precisely monitors and balances all three series strings, maximizing the pack's cycle life and preventing catastrophic imbalances.
End-to-End Engineering Partner
We don't just sell cells; we are your power engineering team. From selecting the right 21700 model to designing the custom housing and managing global certifications, we provide a complete, plug-and-play solution.
18650 Battery Tips
FAQ for 3S (11.1V) 21700 Battery Packs
The primary advantage is energy density and simplicity. To achieve a high capacity like 9000mAh at 11.1V using standard 3000mAh 18650 cells, you need a 9-cell pack (3S3P). Using high-capacity 4500mAh 21700 cells, we achieve the exact same 9000mAh with only 6 cells (3S2P). This reduces the pack’s physical size, lowers the overall weight, requires fewer spot welds (increasing reliability), and simplifies the BMS balancing logic.
Yes, and often more. Because the 21700 has a larger physical volume, manufacturers can use thicker internal current collectors (tabs) and optimize the chemistry for extreme power delivery. We source specific “High-C” 21700 cells that can comfortably sustain 30A, 40A, or even higher continuous discharge currents, making them exceptional for high-torque motors and racing drones.
Let’s compare a ~4500mAh 3S1P 21700 pack vs. a ~5000mAh (2x2500mAh) 3S2P 18650 pack. Three 21700 cells weigh roughly 210g (3 x 70g). Six 18650 cells weigh roughly 270g (6 x 45g). The 21700 pack is significantly lighter, plus you save additional weight on the extra nickel strips and holder materials needed for the larger 18650 array. This weight saving is critical for UAVs and handheld tools.
A 3S pack consists of three lithium-ion cells in series. Since each cell has a maximum charge voltage of 4.2V, the entire pack must be charged with a dedicated lithium-ion charger outputting exactly 12.6V (3 x 4.2V).
Yes. In a series circuit, if one cell (or parallel group) ages differently or has slightly different internal resistance, its voltage will drift away from the others over time. A BMS with a balancing function constantly monitors all three series nodes (the “3S” part) and bleeds off tiny amounts of current from the highest voltage cells during charging, ensuring all three reach 4.2V simultaneously. This is essential for the safety and long-term capacity of the pack.
Thermal management is a core part of our design process. First, we select low internal resistance (low-IR) 21700 cells to minimize heat generation at the source. Second, we use heavy-gauge pure nickel busbars to reduce connection resistance. Third, for packs under heavy continuous load, we design custom cell holders that create physical air gaps between the cells, allowing heat to dissipate efficiently, rather than packing them tightly together. The BMS also includes thermal sensors to cut power if limits are exceeded.
Absolutely. The cylindrical format gives us great geometric flexibility. For a 3-cell (3S1P) pack, arranging them in a triangular block is very popular because it creates a very compact, structurally rigid pack that fits well into many device housings, such as power tool handles or drone fuselages.
It depends on the pack’s total energy capacity (Watt-hours or Wh). The FAA/IATA limit for carry-on is generally 100Wh. Our 3S1P 4500mAh pack is roughly 49.9Wh (11.1V x 4.5Ah), so it flies easily. Our 3S2P 9000mAh pack is 99.9Wh, specifically designed to maximize capacity while remaining just under the unrestricted 100Wh limit. Packs exceeding 100Wh (like a 3S3P 12Ah pack at 133.2Wh) may require airline approval or must be shipped as cargo. All our packs are tested to UN38.3 standards for safe transport.
Due to the engineering complexity, custom BMS requirements, specific cell holders, and safety testing involved with high-energy multi-cell packs, our Minimum Order Quantity (MOQ) typically starts around 10,000 units for professional B2B applications.
To engineer the perfect, safest, and most powerful 11.1V battery pack, our engineers need a clear picture of your power system. Providing these details allows us to move rapidly from concept to a precise design:
Target Capacity (mAh or Ah): Determines the runtime and whether we use a 3S1P, 3S2P, or larger configuration.
Continuous & Peak Discharge Current (Amps) / Motor Wattage: The most critical factor; it dictates cell choice (High-Capacity vs. High-C) and the power rating of the BMS and wiring.
Maximum Dimensions: The exact L x W x H of the battery compartment, so we can determine the optimal layout (e.g., triangle, flat, stacked block).
Charging Parameters: The charging voltage (12.6V) and current (A) your system provides, so we match the BMS accordingly.
Wiring & Connectors: Required wire gauge (AWG), length, and high-current connector type (e.g., XT60, Anderson) ensuring the prototype is plug-and-play ready.
The Application & Environment: Knowing if it’s for a medical device indoors or a drone outdoors helps us understand requirements for durability, temperature range, and certifications.