Successfully Built a 5S LiFePO4 Battery Pack

[ASICS]

I’m excited to share that I’ve successfully built a 5S LiFePO4 battery pack! This was my first attempt at creating a battery pack, and I wanted to document the process and share some insights for anyone interested in doing the same.

Planning and Components
First, I planned out the battery pack specifications and gathered all the necessary components. Here’s a brief overview of what I used:

Battery cells: 5 LiFePO4 cells connected in series
Battery Management System (BMS): To ensure safe operation and cell balancing
Nickel strips: For connecting the cells
Wires and connectors: For completing the circuit and connecting to the load/charger
Heat shrink tubing and insulation materials: For safety and protection
Assembly Process
Cell Preparation: I started by preparing the battery cells, ensuring they were all at the same voltage level for uniformity.
Series Connection: I connected the cells in series using nickel strips and spot welded them to ensure a strong connection.
BMS Connection: I connected the BMS to the battery pack, ensuring each cell was connected to the corresponding point on the BMS for monitoring and protection.
Final Connections: Added the main positive and negative wires, making sure to use proper connectors for secure and reliable connections.
Insulation and Protection: Used heat shrink tubing and additional insulation materials to protect the cells and connections from any potential short circuits or physical damage.
Testing and Results
After assembling the battery pack, I conducted several tests:

Voltage Check: Verified the overall voltage of the pack and individual cell voltages to ensure proper series connection.
Load Test: Connected the pack to a load and monitored the performance, checking for any signs of imbalance or overheating.
Charging Test: Charged the pack with a compatible charger, ensuring the BMS was functioning correctly and balancing the cells.
Insights and Tips
Safety First: Always prioritize safety. Wear protective gear and ensure you’re working in a safe environment.
BMS Importance: A good BMS is crucial for the longevity and safety of the battery pack.
Cell Uniformity: Start with cells that are as closely matched in capacity and voltage as possible.
Overall, the process was a learning experience, and I’m quite pleased with the results.

Hope this helps anyone interested in battery pack building!

[armandine2]

congrats on your success - don't forget to mention in detail:

BOM

test gear

spot welder

etc

testing and photos 

[tunk]

Many BMSs don't do balancing, and if your does, you
may want to test if it can handle large unbalances.