Lithium Ion Battery Pack

Objective

Constructing the lithium-ion battery for my high-draw application was a challenging but rewarding process. The criteria for the project were as follows

• Active battery management system, cell charging and balancing

• Capable of discharging 150A @ 48V

• Fit within the scooter frame

• Temperature shutoff

• Won't catch on fire!

Process

I designed and 3D-printed a custom cell spacer to ensure proper ventilation between cells, prioritizing fire prevention and adherence to best practices. To manage the 14-cell configuration, I integrated a Battery Management System (BMS) to regulate temperature, monitor performance, and enforce draw cutoffs for safety and efficiency.

To optimize performance and minimize risks, I consulted ampacity charts to select appropriately rated wire thickness and used spot-welding techniques for sturdy connections. This approach minimized power loss and excessive heat buildup, ensuring a reliable and efficient energy delivery system.

Result

The battery has performed flawlessly, providing up to 15 miles of range at a weight of just under 11 pounds.

Battery Specs:

• 51.8v nominal voltage

• 20AH nominal capacity

• 150A Continuous discharge max

• Dimensions 19" x 10"