This heat shrink is designed for battery packs and has a 2:1 shrink ratio. It measures 220 mm (8-5/8 inches) across when flattened, and has an opened diameter of 140 mm (5-1/2 inches). It can fit any Vruzend battery from 3-5 cells wide. With a tight squeeze, 6 cells can fit, but there won’t be any room for padding or a BMS on the side, so you’d need to mount your BMS on the end of the pack or outside the pack.
The heat shrink is sold by the foot. If you order multiple quantities, you’ll get a continuous piece measuring that many feet long. For example, if you order 3 units, you’ll get a single 3 foot piece of heat shrink.
The heat shrink can be used directly around the Vruzend battery, but the posts on the Vruzend caps will create stress points that could begin to fatigue the heat shrink over time, especially if you are picking up and moving your battery a lot. If you plan on moving your battery around, we recommend using a couple layers for durability. It will also help if you use a rigid layer under the heat shrink, such a flexible plastic cutting board from the dollar store. This creates a hard, flat shell over the two sides of the Vruzend caps and keeps the heat shrink from being squeezed down on the posts.
Make sure you calculate how many feet you’ll need. Most packs up to 13 cells long can use a single foot, but 14 cells or more in length will require an extra foot. Also, you might want extra, just in case the shrinking process takes you a few tries.
It is best to use a heat gun on a low or medium setting to shrink the heat shrink tube, but a strong hair dryer on high can also work in a pinch.