Description
BAK 2S 7.4V 40000mAh 2S8P 3C Lithium-Ion Battery Pack | Rechargeable NMC Battery
BAK 2S 7.4V 40000mAh 2S8P 3C Lithium-Ion Battery Pack is a high-capacity rechargeable NMC lithium-ion battery pack designed for applications requiring a compact 7.4V power source with high energy capacity and high discharge capability.
Built using BAK lithium-ion cells in a 2S8P configuration, this battery provides a nominal voltage of 7.4V and a large capacity of 40Ah (40,000mAh). The 3C cell rating provides a theoretical discharge capability of up to 120A, although the actual usable current of the finished pack depends on the BMS, interconnects, wiring, connectors and thermal conditions.
The battery can be supplied with a suitable 2S NMC BMS for protection against overcharge, over-discharge, over-current and short circuit. Connector, wire length, BMS rating and pack dimensions can be customized for OEM and application-specific requirements.
2S8P Configuration Explained
The 2S8P configuration consists of 16 cells:
- 2S = 2 cell groups connected in series
- 8P = 8 cells connected in parallel in each group
- Total cells = 2 × 8 = 16 cells
- Cell capacity = 5Ah
- Pack capacity = 8 × 5Ah = 40Ah
- Nominal voltage = 3.7V × 2 = 7.4V
- Full-charge voltage = 4.2V × 2 = 8.4V
- Energy = 7.4V × 40Ah ≈ 296Wh
The series connection determines the voltage, while the parallel connection increases capacity and current capability.
3C High-Discharge Capability
With a rated capacity of 40Ah and a 3C cell discharge specification:
40Ah × 3C = 120A theoretical discharge current
This is a theoretical calculation based on the cell rating. The finished battery’s actual continuous and peak current capability must be selected according to the BMS, cell model, busbars/interconnects, wiring, connector and thermal design.
BMS Protection
A suitable 2S NMC BMS can provide protection for:
- Overcharge
- Over-discharge
- Over-current
- Short circuit
- Cell voltage imbalance
- Temperature monitoring when supported
- Charge and discharge fault conditions
For high-current applications, Lion Battery can configure the pack with a suitable BMS according to the required load.
Charging
The battery should be charged using a compatible 8.4V NMC/Li-ion CC/CV charger.
| Charging Parameter | Recommended Specification |
|---|---|
| Nominal Voltage | 7.4V |
| Full-Charge Voltage | 8.4V |
| Battery Chemistry | NMC Lithium-Ion |
| Charging Method | CC/CV |
| Charger | 8.4V Li-ion Charger |
| Charging Current | Application dependent |
Do not use a 12.6V 3S charger for this 2S battery.
Key Features
- BAK lithium-ion cell technology
- 7.4V nominal voltage
- 40Ah / 40,000mAh high capacity
- 2S8P configuration
- NMC lithium-ion chemistry
- 3C high-discharge cell specification
- Approximately 296Wh energy
- Rechargeable battery design
- BMS protection
- High-capacity power solution
- Custom BMS options
- Custom connector and cable options
- Suitable for OEM and bulk requirements
Applications
The 7.4V 40Ah battery pack can be used for:
- Robotics
- AGV and AMR systems
- Portable power equipment
- Industrial equipment
- Communication systems
- CCTV and security equipment
- Backup power systems
- Portable instruments
- Mobility equipment
- RC and high-power projects
- Electronic equipment
- Research and development projects
- OEM machinery
- Custom power systems
Custom Battery Pack Manufacturing
Lion Battery provides custom lithium battery pack manufacturing for OEM, ODM, private-label and bulk requirements.
We can customize:
- Battery voltage
- Battery capacity
- NMC / LiFePO4 chemistry
- Series and parallel configuration
- Cell brand
- BMS current rating
- Smart BMS / communication BMS
- Connector type
- Wire gauge and length
- Pack dimensions
- Enclosure
- Insulation and protection
- Charging connector
- OEM/private-label branding
