Learn more about DIY lithium batteries with my Amazon #1 bestselling book: http://a.co/1ERTSmo How to build a lithium battery - Part 4: Sealing a battery For part 1: battery layout, see here: https://www.youtube.com/watch?v=b3eRv_FZjBc For part 2: spot welding, see here: https://www.youtube.com/watch?v=ublFs7IU05c For part 3: BMSs, see here: https://www.youtube.com/watch?v=u-4mKh1WaLo The final chapter will be coming soon: Part 5: Choosing an appropriate charger The parts I use for battery building: 18650 cells (Sanyo GA 3500mah): https://goo.gl/J6ONJV 18650 cells (another Sanyo GA 3500mah source): https://goo.gl/f10wHH 18650 cells (Samsung 26F 2600mah): https://goo.gl/VhpP7T 18650 positive insulating washer: https://goo.gl/HBVOuc Ebike battery cases: https://goo.gl/W2DLmE Nickel strip: http://goo.gl/VIrNQq Spot welder: https://goo.gl/KN3Uaw BMSs: http://goo.gl/S6gSQx Silicone wire: http://goo.gl/xmpbKD Black 18650 cell spacers: http://goo.gl/hQxWF6 Large heat shrink tubing: http://goo.gl/6v1ow9 Small heat shrink tubing: https://goo.gl/OU3Z6u Foam sheet for protecting battery: http://goo.gl/5e71tE Kapton tape: https://goo.gl/D6BT57 Chargers: https://goo.gl/js0T0V If you'd like a written step-by-step guide showing how to build an electric bicycle battery, see my article here: http://www.ebikeschool.com/how-to-build-a-diy-electric-bicycle-lithium-battery-from-18650-cells/