Packaging method of calculation: to find the size you need, measure the widest cross-section circumference of your Pack and then divide it by 2 use the shrink wrap size at least 5mm (1/5 inch) wider than your half circumference value. PVC heat shrink tubing suit for packaging the 18650, 18500and 18530 battery.all18mm diameter batteries are suitable for. Our shop also has other PVC heating shrink tube for multiple batteries, details please contact customer service. The battery is not heated when the tube is full shrinkable. And must not continue heat the tube, after it is full shrinkable. The battery is not included.