Lithium Polymer (LiPo) batteries have become the power source of choice for drones, RC cars, boats, and robotics. Their ability to deliver high energy density, lightweight construction, and strong discharge rates makes them superior to older battery technologies such as NiMH or NiCd.
Among the various LiPo configurations, the 2S LiPo battery holds a special place. With two cells connected in series and a nominal voltage of 7.4V, it is widely used across hobby-grade and professional devices. But when choosing a LiPo pack, understanding the standard sizes and capacities is crucial for ensuring proper fit, performance, and safety.
This article will guide you through everything you need to know about 2S LiPo battery capacities, common sizes, and best applications, so you can make an informed choice for your project or RC model.
Basics of 2S LiPo Batteries
What Does “2S” Mean?
The term “2S” refers to two cells connected in series inside the battery pack. Each LiPo cell has a nominal voltage of 3.7V. When two are linked in series, the pack delivers a total nominal voltage of 7.4V.
- Fully charged voltage: 8.4V (4.2V per cell).
- Safe discharged voltage: Around 6.0V (3.0V per cell).
This voltage range makes 2S batteries a sweet spot for many RC devices, as it balances power and efficiency without adding unnecessary weight.
Key Terminology You Should Know
Before exploring sizes and capacities, let’s define a few critical battery terms:
- mAh (milliampere-hour): Determines how long the battery will last. A 2200mAh battery theoretically provides 2.2 amps for one hour.
- C-rating (discharge rate): Indicates how quickly the battery can safely discharge. A higher C-rating supports more powerful motors but can add bulk.
- Dimensions & Weight: Essential for fitting into your drone, RC car, or boat. Even the right capacity won’t help if the pack doesn’t physically fit.
Standard Capacities of 2S LiPo Batteries
Common Capacity Ranges
2S LiPo batteries are manufactured in a wide range of capacities, typically from 500mAh to 10,000mAh. Below are some of the most common ranges:
- 500–1000mAh: Small indoor drones, micro planes, and compact RC toys.
- 1500–2200mAh: The most popular range for mid-sized drones, quadcopters, and RC planes. The 2200mAh pack is a global standard for versatility.
- 3000–5000mAh: RC cars, boats, and FPV drones requiring extended run time.
- Above 5000mAh: Heavy-duty drones, robotics, and large-scale RC vehicles needing high endurance.
How Capacity Affects Performance
Capacity directly impacts how long your battery will last. However, higher mAh batteries are also heavier. This creates a trade-off between endurance and agility:
- Higher capacity: Longer runtime but heavier load on motors.
- Lower capacity: Lightweight, better for racing drones, but shorter flight time.
Example: A 2200mAh 2S LiPo may power a drone for around 8–12 minutes, whereas a 5000mAh pack could last over 20 minutes in the same model—but the added weight may reduce maneuverability.
Standard Sizes & Dimensions
Typical Physical Sizes of 2S LiPo Packs
The physical size of a 2S LiPo battery is determined by its capacity, discharge rating, and casing. While there is no universal standard, here are approximate dimensions:
- Small Packs (500–1000mAh): 50 x 30 x 12 mm.
- Medium Packs (1500–2200mAh): 100 x 35 x 20 mm.
- Large Packs (3000–5000mAh): 140 x 45 x 25 mm.
Factors Affecting Battery Size
- Capacity (mAh): Higher capacity requires larger cells.
- Discharge Rate (C-rating): High-performance packs may be thicker.
- Casing Type: Hard cases protect against impacts (used in RC cars), while soft packs are lighter (used in drones).
Popular Form Factors by Application
- Flat soft packs: Used in FPV drones for weight reduction.
- Hard case packs: Used in RC cars to prevent punctures during crashes.
- Slimline packs: Used in robotics where compact form factors are needed.
Application-Based Sizing & Capacity Recommendations
For Drones & FPV Aircraft
- Typical capacity: 850mAh to 2200mAh.
- Prioritize weight reduction for better agility.
- Example: Racing drones often prefer 850–1300mAh packs, while aerial photography drones lean toward 1800–2200mAh.
For RC Cars & Trucks
- Typical capacity: 3000–5000mAh with hard casing.
- High discharge rates (35C–50C) needed for rapid acceleration.
- Example: A 2S 5000mAh 50C hard pack is a common choice for 1/10 scale RC trucks.
For Boats & Robotics
- Boats require endurance: 4000–7000mAh packs are common.
- Robotics often use higher capacity batteries for continuous operation.
- Example: Autonomous robots may use 2S 6000mAh for steady, long-duration performance.
Choosing the Right 2S LiPo Battery
Considerations Before Buying
- Device requirements: Check voltage and connector type.
- Battery compartment dimensions: Ensure physical fit.
- Runtime expectations: Decide between endurance vs. lightweight agility.
- Weight limitations: Critical for drones.
- Safety standards: Stick with reputable brands to avoid swelling or fire risk.
Tips for Optimal Usage
- Use a balance charger to ensure both cells charge evenly.
- Match C-rating with motor/ESC requirements.
- Store at 3.8V per cell (storage charge) for longevity.
- Avoid overcharging or discharging below 3.0V per cell.
Safety and Maintenance of 2S LiPo Batteries
Conclusion
2S LiPo batteries are incredibly versatile, powering everything from tiny drones to large RC trucks and autonomous robots. Their standard sizes and capacities typically range from 500mAh to over 7000mAh, with physical dimensions varying by design.
Choosing the right 2S pack means considering capacity, weight, size, discharge rate, and application-specific needs. A 2200mAh 2S battery may be perfect for your drone, while a 5000mAh hard case may suit your RC car.
Ultimately, the best battery is one that balances performance, safety, and compatibility. By understanding the standard sizes and capacities available, you can make confident decisions that enhance your device’s efficiency and lifespan.
Frequently Asked Questions (FAQs)
1. What is the nominal voltage of a 2S LiPo battery?
A 2S LiPo has a nominal voltage of 7.4V and a fully charged voltage of 8.4V.
2. What is the most common capacity for a 2S LiPo battery?
The 2200mAh pack is one of the most widely used, balancing runtime and weight for drones and RC models.
3. Can I use a higher capacity 2S LiPo in my RC car or drone?
Yes, as long as it fits physically and does not exceed your model’s weight or ESC limits.
4. What is the difference between a hard case and a soft pack 2S LiPo?
- Hard case: Durable, used in RC cars and trucks.
- Soft pack: Lightweight, used in drones and aircraft.
5. How do I know what size 2S LiPo battery will fit my device?
Check the battery compartment dimensions in your drone or RC vehicle’s manual.
6. Does a higher C-rating always mean better performance?
Not always. A higher C-rating supports faster discharge but may add bulk. Match it to your motor and ESC requirements.
7. How long can a 2S 2200mAh LiPo battery last in a drone?
On average, 8–12 minutes, depending on flying style, motors, and payload.
