2kWh lithium ion battery (12v)

Building a DIY 2kWh Lithium-Ion Battery Pack for 12V DC Applications

Introduction

In this article, I explain how I built a 2kWh lithium ion battery pack capable of delivering stable 12V DC power. The pack is constructed using high quality lithium ion cells from My Sky Power.

The system uses 216 cells arranged in a 3S72P configuration, producing a total capacity of approximately 2000Wh. For safety and performance control, I integrated two 100A Battery Management Systems. The battery pack can deliver a continuous output of 200A and supports charging currents up to 100A.

Battery Configuration Explained

To achieve the required voltage and capacity, I connected the cells in both series and parallel configurations.

• 3 cells in series provide approximately 12V
• 72 parallel groups increase total capacity
• Total configuration: 3S72P

This structure ensures a balance between voltage stability and high energy storage while maintaining strong current capability.

Total Energy Capacity

Each lithium ion cell provides 9.25Wh of energy.

216 cells × 9.25Wh = approximately 2000Wh or 2kWh

This allows the battery pack to store a large amount of usable energy suitable for demanding applications.

Safety and Protection with Dual BMS

To ensure safe operation, I installed two 100A Battery Management Systems.

The BMS units continuously monitor:

• Voltage
• Current
• Temperature

They protect the battery from:

• Overcharging
• Over discharging
• Short circuits
• Excessive current draw

Using dual BMS units increases reliability, improves load handling, and extends the lifespan of the battery pack.

Power Output and Charging Performance

This battery pack can deliver up to 200A continuous output, making it suitable for high power applications such as:

• Electric vehicles
• Off grid solar systems
• Marine systems
• High power DC loads

It also supports charging currents up to 100A, allowing faster recharge times when paired with an appropriate charger.

Designed and Built Under My Sky Power

I built this battery pack under My Sky Power using carefully selected lithium ion cells and quality components. My focus was on safety, efficiency, and long term durability.

By combining proper cell balancing, strong current capability, and reliable protection systems, I created a high performance energy solution suitable for professional and DIY use.

Conclusion

Building a 2kWh 12V lithium ion battery pack is both practical and powerful when designed correctly.

With a 3S72P configuration, dual 100A BMS protection, 200A discharge capability, and 100A charging support, this system delivers strong and reliable performance for demanding DC applications.

This project demonstrates how proper engineering, quality components, and careful assembly can produce a durable and efficient energy solution for modern power needs.