PVC Heat Shrink Tubing – Wide Flat Wrap for Battery Packs & Wire Insulation

Measure the circumference of your substrate (battery cell, wire bundle, etc.) and divide by 2 — that gives you the minimum flat width you need. For example, a standard 18650 cell is about 18.5mm in diameter, so its circumference is roughly 58mm, meaning you'd generally want a flat width of at least 29.5mm–31mm for a snug fit. For flat LiPo packs, measure the widest flat dimension and add a small margin. When in doubt, size up — you can always apply more heat to tighten the fit, but you can't stretch tubing that's too small.

Standard PVC heat shrink tubing typically has a 2:1 shrink ratio, meaning it will shrink to approximately half its original flat width when heated. For example, a 50mm flat-width piece will generally recover to around 25mm flat (or roughly 16mm diameter). Actual shrink performance can vary slightly by width and color, so we recommend testing on a scrap piece first for critical applications.

PVC heat shrink tubing generally provides good moisture resistance once shrunk, making it suitable for many indoor and sheltered outdoor applications. However, for fully waterproof or submersible applications, we recommend using adhesive-lined (dual-wall) heat shrink tubing instead. If you're unsure whether this product meets your environmental requirements, please contact us before ordering.

Yes — wide flat PVC heat shrink tubing is one of the most common materials used for wrapping 18650 and 21700 battery packs. The flat-lay format slides easily over assembled cell groups, and the tubing shrinks evenly around the pack when heat is applied. For a standard 4P or 5P 18650 pack, widths in the 50mm–85mm range are typically used, depending on the pack configuration. Always confirm your pack dimensions before selecting a size.

A heat gun is the recommended tool for even, controlled shrinking — typically set to around 90°C–120°C (194°F–248°F). A lighter or butane torch can work for small diameters but requires careful technique to avoid scorching. Avoid using a standard hair dryer, as it generally does not produce enough heat to fully activate PVC shrink tubing. Move the heat source evenly along the length of the tubing to prevent uneven shrinkage or bubbling.

Yes — PVC heat shrink tubing is widely used in automotive wiring for insulating soldered splices, protecting exposed terminals, and bundling wire looms. For engine bay applications where temperatures can exceed 100°C, we recommend verifying the tubing's temperature rating for your specific use case. For high-heat zones near exhaust components, a polyolefin or adhesive-lined tubing may be more appropriate.

Yes — transparent and tinted transparent variants (such as Transparent Gold and Transparent Blue) are made from the same PVC material and generally provide equivalent electrical insulation and shrink performance as solid-color options. The transparent finish is popular for applications where you want to display labels, markings, or the substrate underneath after shrinking.