21700 Battery PVC Heat Shrink Wrap - 35mm Flat Width - Cut-to-Length Roll - Blue

Blue PVC heat shrink tubing sized for 21700 lithium cells, supplied as a continuous cut-to-length roll. Cut each sleeve to exactly the length you need, whether that is a single cell, two cells end to end, or a custom length, and pay far less per cell than pre-cut sleeves.

How many cells per roll

• 5 meters: approx. 62 cells
• 10 meters: approx. 125 cells
• 20 meters: approx. 250 cells

Based on about 80mm per sleeve (a 70mm cell plus overhang at each end). Your count will vary slightly with how much overhang you leave.

Specifications

• Flat width: 35mm (approx. 22mm diameter before shrinking)
• Fits: 21700 cells
• Colour: blue
• Material: PVC heat shrink film
• Sold as a continuous roll, cut to length by you

What it is used for

Rewrapping harvested or salvaged 21700 cells, replacing torn or damaged factory wrap, and colour-coding cells during pack assembly. A cell with damaged wrap can short against a neighbouring cell or the pack housing, so rewrapping is a basic safety step in any rebuild.

How to use

1. Remove the old wrap and any adhesive residue from the cell.
2. Fit an insulator ring over the positive terminal if the original was removed.
3. Cut a sleeve about 10mm longer than the cell (approx. 80mm for a 21700).
4. Slide the sleeve over the cell, leaving an equal overhang at each end.
5. Apply gentle heat with a heat gun, turning the cell so the film shrinks evenly.

Keep the heat moving and do not overheat the cell. A hair dryer on high will also work, more slowly.

Safety

Rewrapping does not repair a damaged cell. Cells that are dented, swollen, leaking, or that fail a capacity or internal resistance check should be recycled, not rewrapped.