For my projects, I've realized the need for batteries with various capacities and power outputs. While lithium-polymer (LiPo) batteries are an option, they tend to be expensive and have limitations in terms of maximum safe discharge voltage and energy density. Consequently, I have decided to create my own lithium-ion (Li-ion) batteries. This approach not only offers a cost-effective solution but also provides a valuable learning opportunity. Undertaking this project, I aim to enhance the professionalism of my work and ensure a more efficient power flow.
Safety Precautions and Required Tools & Materials
When assembling a Li-Ion battery pack, Firstly I dedicated a clean, well-lit table specifically for the assembly, creating an organized and hazard-free workspace. to protect against any potential issues like sweat-induced short circuits, I used gloves during the entire process. Additionally, for an extra layer of safety, I kept a fire extinguisher within easy reach.
For the assembly materials and tools, I sourced high-quality Li-Ion cells from reputable dealers such as Robu.in and Robokits, valuing their track record for genuine and reliable products. A DIY spot welder was an important tool in my setup for safety and a good connection. I also used a Battery Management System (BMS) for safe battery operation, along with nickel strips for effective connections, heat shrink tubing for insulation and silicone wire. These, combined with other essential electrical project instruments and tools.
Design and Assemble the Battery Pack
My plane required a 16V power supply, so I decided to build a 4S battery pack using SAMSUNG ICR 18650-26J Li-ion cells. To assemble it, I used 0.5mm nickel strips, 18 AWG silicone wires, and a portable spot welder powered by a 3S LiPo battery. After completing the battery pack, I tested it by drawing 10 amps. However, I noticed a significant voltage drop to around 15V, which was unacceptable for my application. This made me realize that the SAMSUNG ICR 18650-26J cells were not suitable for my use case.
To resolve the issue, I considered alternative cells, including LG Chem cells and Molicell INR-21700-P45B. After evaluating my options, I decided to go with the Molicell INR-21700-P45B due to its superior performance and ability to handle higher current demands efficiently.
