TLDR;
In this video, Rob Cameron demonstrates how to build a custom 52-volt 25-amp battery for an ebike, aiming to enhance its performance compared to the stock battery. The process involves understanding battery theory, selecting suitable materials, and following a series of steps including assembly, welding, wiring, and testing. Key takeaways include:
- Utilization of 18650 lithium-ion cells for battery construction.
- Importance of calculating series and parallel configurations to achieve desired voltage and capacity.
- Incorporation of a Battery Management System (BMS) for safety and performance monitoring.
- A step-by-step approach to assembling and testing the battery.
Intro [0:00]
Rob introduces the project of building a powerful battery for his son's Rad Power Rad Runner 2 ebike. He plans to create a 52-volt 25-amp battery that will enhance range and speed, using 18650 lithium-ion cells. He mentions that he will document the entire building process, showing various tools used and emphasizing safety.
Battery Theory [1:15]
Rob explains the nominal voltage of 18650 cells (3.6 or 3.7 volts), their capacity (3200 milliamp hours), and how to increase both voltage and capacity by wiring them in series and parallel. He discusses the configurations needed to achieve 52 volts and 25,600 milliamp hours, ultimately resulting in a 14s8p (14 in series, 8 in parallel) battery pack, which requires a total of 112 cells.
Battery Shopping [4:49]
Rob shares his decision-making process in selecting the cells for his battery. He explains how to compare specs like capacity, continuous discharge rating, and pricing. He chose Eve 33 cells for their high capacity and decent discharge rating, while also considering alternatives like Samsung batteries for their discharge capabilities. He emphasizes the importance of having flat top cells and highlights different cell sizes available.
Pack Assembly [8:25]
Rob begins the assembly of the battery pack, showing the 18650 battery brackets that will hold the cells together. He emphasizes safety, ensuring the cells have similar voltage before connecting them. After testing for voltage consistency, he arranges the cells in parallel rows and secures the bracket assembly.
Pack Welding [14:15]
He prepares to weld nickel strips to connect the cells. Rob cuts the nickel strips to size and explains the importance of using pure nickel for effective conductivity. He demonstrates the welding process with a battery welder, ensuring the welds are solid to maintain structural strength and minimize heat damage to the cells.
Pack Wiring [23:16]
Rob wires the completed battery pack to its BMS, discussing the significance of each connection in monitoring the voltage of the parallel rows. He explains the balancing process that the BMS performs and prepares the battery for final connections.
Heat Shrink [33:24]
Rob shows how to effectively heat shrink the battery pack to protect it. He uses EVA foam for cushioning against vibration during rides, demonstrating how to apply heat shrink to maintain the integrity of the battery. The goal is to ensure the pack is durable and secure for installation on the bike.
Install & Test Ride [35:40]
In the final segment, Rob installs the new battery onto the ebike, connecting the wiring to the bike's controller. Once everything is set, he takes the bike for a test ride to evaluate the performance of the new battery pack, showcasing the enhanced power and responsiveness of the ride.
