2S 7.4V 18650 Li-ion Battery Pack with 8.4V Polymer Cell & 8A Continuous/16A Peak Protection Circuit

SKU: FA2193-04
Configuration

2S (2-cell series)

Nominal Voltage

7.4V

Full Charge Voltage

8.4V

Cell Type

18650 Li-ion / Polymer compatible

Continuous Discharge Current

8A

Peak Discharge Current

16A

Protection Functions

Overcharge, over-discharge, overcurrent

Connection Type

Solder pads or connector (variant dependent)

The 2S 7.4V 18650 Li-ion Battery Pack with 8.4V Polymer Cell & Protection Circuit is a complete, ready-to-use battery solution designed for high-drain applications requiring reliable, protected power. It combines two 18650 lithium-ion cells in a 2S configuration with an integrated 8A continuous / 16A peak protection circuit, making it an ideal power source for portable electronics, RC vehicles, power tools, and DIY projects.

At the heart of the pack is a 2S (2-cell series) configuration, providing a nominal voltage of 7.4V and a full charge voltage of 8.4V. This voltage is compatible with a wide range of devices designed for 2S lithium power, including RC cars, drones, portable speakers, and DIY power banks.

The integrated protection circuit continuously monitors the voltage of each cell and the total pack current, disconnecting the load or charger if any parameter exceeds safe limits. This protects both the battery pack and your connected devices from damage, extending battery lifespan and ensuring safe operation.

The protection circuit provides three critical protection functions:

  • Overcharge protection — Disconnects the charger when any cell voltage reaches approximately 4.25V to 4.3V, preventing damage from excessive charging.

  • Over-discharge protection — Disconnects the load when any cell voltage drops to approximately 2.5V to 3.0V, preventing deep discharge that can permanently damage the battery.

  • Overcurrent protection — Disconnects the output when current exceeds 8A continuous or 16A peak, protecting against short circuits and excessive loads.

The 8A continuous / 16A peak rating makes this pack suitable for high-drain applications such as power tools, RC vehicles, and high-power portable devices. The 16A peak rating provides a safety margin for brief current surges, while the 8A continuous rating ensures reliable operation under sustained loads.

The pack features a solder pad or connector design for easy integration into your project. The compact form factor is sized to fit into battery compartments and custom enclosures. The pack includes B+, B-, BM (mid-point), P+, and P- connections for battery and output.

The “18650” designation indicates the pack uses standard 18650 lithium-ion cells, which are widely available, reliable, and offer excellent energy density. The “Polymer Cell” reference indicates compatibility with lithium-polymer cells as an alternative, providing flexibility in cell selection.

Important Note: This battery pack is designed for 2S (2-cell) 7.4V applications. Always verify the voltage and current ratings match your application before installation. Use an appropriate 2S lithium battery charger with balance charging capability.

Whether you are building a custom power bank, powering an RC vehicle, or designing a portable device, the 2S 7.4V 18650 Li-ion Battery Pack with Protection Circuit provides a reliable, protected power solution. It is suitable for individual makers, students, and businesses purchasing in bulk for product development or educational programs.


Features

  • 2S dual-cell configuration — Provides 7.4V nominal / 8.4V full charge voltage

  • 8A continuous / 16A peak protection — High-current capability for demanding applications

  • Comprehensive protection — Overcharge, over-discharge, and overcurrent protection

  • Cell balancing — Ensures even charge and discharge across both cells

  • 18650 cell compatibility — Uses standard, widely available lithium-ion cells

  • Polymer cell compatible — Flexible cell selection for different requirements

  • Compact form factor — Sized for battery compartments and custom enclosures

  • Wide application range — Power tools, RC vehicles, portable devices, DIY projects


Technical Specifications 

# Parameter Specification
1 Configuration 2S (2-cell series)
2 Nominal Voltage 7.4V
3 Full Charge Voltage 8.4V
4 Cell Type 18650 Li-ion / Polymer compatible
5 Continuous Discharge Current 8A
6 Peak Discharge Current 16A
7 Protection Functions Overcharge, over-discharge, overcurrent
8 Connection Type Solder pads or connector (variant dependent)

Usage

Getting Started

  1. Identify the pack terminals — Locate the positive (+), negative (-), and mid-point (BM) terminals of the battery pack.

  2. Connect the load or charger — Connect your device or charger to the P+ and P- pads on the protection circuit.

  3. Charge the pack — Use an appropriate 2S lithium battery charger with balance charging capability. Charge at a rate not exceeding the pack’s recommended charge current.

  4. Test the protection — Verify that the output voltage is present when the pack is within safe limits, and that the output disconnects when any cell voltage drops too low or rises too high.

  5. For high-current applications — Ensure all wiring and connections are rated for the maximum current your application will draw.

Protection Thresholds (Typical)

Parameter Threshold Action
Overcharge ~4.25V – 4.3V per cell Disconnect charger
Over-discharge ~2.5V – 3.0V per cell Disconnect load
Overcurrent 8A continuous / 16A peak Disconnect output

Connection Points

Pad Function
B+ Battery pack positive terminal
B- Battery pack negative terminal
BM Mid-point between cells
P+ Protected output positive
P- Protected output negative

Typical Applications

  • Power tools — High-drain power for drills, saws, and other tools

  • RC vehicles — Reliable power for remote-controlled cars and trucks

  • Portable speakers — Power for high-output audio devices

  • DIY power banks — Custom portable chargers with high-current output

  • Drone battery packs — Safe power for small to medium drones

  • Portable electronics — Power for devices requiring 7.4V

  • Educational projects — Teaching battery management and protection principles

Notes for Business Buyers

  • Complete battery solution — Cells, protection circuit, and connections integrated into a single pack.

  • High-current capability — 8A continuous and 16A peak for demanding applications.

  • Cell balancing included — Ensures even charge and discharge for longer pack life.

  • Suitable for bulk purchasing — Ideal for product development, RC hobby shops, and educational institutions.

Q: What is the 2S 7.4V Battery Pack used for?

It is a complete battery solution for devices requiring 7.4V nominal power, with integrated protection for safe operation in high-drain applications.

Q: What is the difference between 2S and other configurations?

2S means two cells in series, providing 7.4V nominal (8.4V full charge). Other common configurations include 1S (3.7V), 3S (11.1V), and 4S (14.8V).

Q: What is the continuous and peak discharge current?

The pack supports 8A continuous and 16A peak discharge current.

Q: What are the protection thresholds?

Overcharge protection activates at approximately 4.25V–4.3V per cell. Over-discharge protection activates at approximately 2.5V–3.0V per cell. Overcurrent protection activates at 8A continuous / 16A peak.

Q: What is the difference between B+/-, BM, and P+/-?

B+ and B- connect to the pack positive and negative terminals. BM connects to the mid-point between the two cells. P+ and P- provide the protected output to your load or charger.

Q: Does this pack balance the cells?

Yes. The integrated protection circuit includes cell balancing to ensure both cells charge and discharge evenly.

Q: What charger should I use with this pack?

Use a 2S lithium battery charger with balance charging capability. The charge voltage should be 8.4V, and the charge current should not exceed the pack’s recommended rating.

Q: Can I use this pack with a 1S or 3S device?

No. This pack provides 7.4V nominal output and is designed for 2S-compatible devices. Using it with other voltage configurations may damage your device.

Q: Does the pack protect against short circuits?

Yes. The protection circuit includes overcurrent protection that disconnects the output if a short circuit or excessive current is detected.

Q: Can I purchase in bulk for a product development project?

Yes. This battery pack is suitable for both individual users and business purchasing, including product development, RC hobby shops, and educational institutions.