Re-upload: This is a re-release addressing early feedback from the original video, in which I referred to all of the lithium batteries as Lipo, even when 18650s are most commonly Li-ion in chemistry. Pictured in the video and linked in the description was a website about the differences between various lithium batteries, but clearly me constantly using the term Lipo was confusing and misleading. Therefore, I present this minor edited version to correct the problem. My apologies for the original error and I hope this tweaked version can be the informative video I originally set out to make. Last year I discovered the world of custom 18650 battery building. You take li-ion cells, new or recycled, and build a battery to your exact project specifications. There’s a lot of conflicting information out there and many potential safety hazards. In this video I compile many weeks of research into an introductory guide for building batteries safely. Please pay close attention to the safety warnings and tips in this video. Always consult a professional, not just onlines videos and forums, before building a custom battery. This video is solely intended to get you up to speed before you check your plans with a professional. In a future video, I will be building a high voltage, high current custom battery to power a small EV. 0:00 Introduction 0:51 What are 18650s? Tesla 18650 battery: 2:04 Voltage, current and capacity: series vs parallel Lithium battery FAQ: 4:39 Example battery calculations Battery calculator: 7:28 How to shop for 18650s How to spot fake VTC cells by Mooch: Tech Around You in Aus (recommended by my personal experience): Second Life Storage cell database: 10:15 Testing and managing 2nd hand 18650s Opus charger: Repackr website: 11:09 Building battery frame Modular cell holders on Amazon: Example cell holder on Thingiverse: :1452396 11:44 Nickel joining strips How to identify pure vs coated Nickel strips: Matador’s nickel strip rating chart: 12:54 Spot welding the cells together K-Weld spot welder: 14:41 Solder/spot weld less option: VRUZEND VRUZEND weldless 18650 kit: 15:08 Balance leads, terminals and charging Rosin flux paste: Fish paper: Kapton tape: 17:31 Finished 3D printer battery 17:51 BMS - Battery management systems Daly BMS website: 18:41 Conclusion Previous portable MPMD video: Endless-sphere forums: Reddit 18650 sub: Buy quality and affordable filament from X3D. Buy 3, get 1 free and a free sample pack with every order: Get Quality Resins from 3D Printers Online. 5% off storewide for Teaching Tech subscribers [Code: tech5] Take a look around and if you like what you see, please subscribe. Support me on Patreon: