EBike Battery Pack || DIY or Buy || Electric Bike Conversion (Part 2)

Tutorial: How to Create Your Own DIY E-Bike Battery Pack

Step 1: Determine the Voltage Range and Capacity Requirements

• Based on the video, the controller for the E-bike requires a voltage range of at least 40.6 volts to a maximum of 61.5 volts.
• Calculate the nominal voltage based on the number of cells in series. In this case, 13 cells in series provide a nominal voltage of around 48.1 volts.

Step 2: Select the Battery Cells

• Choose suitable batteries with a nominal voltage of 3.6 to 3.7 volts and a maximum charging voltage of 4.2 volts per cell.
• Opt for 18650 lithium-ion cells for their energy density and current delivery capabilities.

Step 3: Determine the Battery Configuration

• Decide on the battery configuration based on the required current output of the controller. In this case, a 13S2P configuration was chosen for a capacity of 5 amp-hours and a constant output current of 40 amps.

Step 4: Assemble the Battery Pack

• Use plastic spacers to hold the cells in place. Connect 13 cells in series and then connect the parallel pairs using nickel ribbon strips.
• Utilize a battery spot welder like kWeld for creating secure welds between the cells.

Step 5: Charge the Battery Pack

• Follow the constant-current constant-voltage charging method recommended for the lithium-ion cells used in the battery pack.
• Set the lab bench power supply to the appropriate current limit and voltage limit for charging.

Step 6: Add a Battery Management System (BMS)

• To ensure all cells stay at an equilibrium voltage and provide protection against overcharging and discharging, add a BMS to the battery pack.
• Solder the balance connector wires of the BMS to the battery cells as per the labeling instructions.

Step 7: Finalize the Connections

• Connect the ground wire of the battery to the B- terminal of the BMS and add additional wires to the P- and C- terminals.
• Charge the battery pack through the BMS to maintain cell balance and safety during charging.

Step 8: Test and Use the Battery Pack

• Once charging is complete, connect your load to the battery pack and verify its functionality.
• Enjoy using your DIY E-bike battery pack for your electric bike conversion.

By following these steps, you can successfully create your own DIY E-bike battery pack for your electric bike conversion project.