4S 18650 Battery Solid Barley Paper Insulating Gasket

4S 18650 Battery Solid Barley Paper Insulating Gasket is a die-cut, self-adhesive highland barley paper (fish paper) electrical insulation pad sized for 4-cell (4S / 4P) 18650 lithium-ion battery pack assemblies. Featuring a continuous solid coverage face (without center holes) and a high-tack acrylic adhesive backing, it is applied over spot-welded nickel strips, battery pack ends, or BMS mounting surfaces to provide tear-resistant dielectric isolation, thermal resistance, and mechanical abrasion protection.

Key Features:

• Full-Surface Solid Dielectric Barrier: Continuous unperforated barley paper sheet completely covers exposed spot-welded nickel strips and cell ends to prevent external short circuits.
• Genuine Highland Barley / Fish Paper Material: Vulcanized cellulose fiber paper resists tearing, puncturing, moisture, and high temperatures up to 120°C–130°C during soldering or heavy discharge.
• Pre-Cut 4-Cell 18650 Footprint: Sized specifically to cover a 4-cell 18650 row or 2×2 pack face without tedious manual cutting.
• Strong Self-Adhesive Backing: Peel-and-stick pressure-sensitive adhesive bonds firmly to steel cell cans, PVC heat-shrink wraps, and nickel busbars.
• Shock & Vibration Cushioning: ~0.2mm–0.3mm fibrous thickness absorbs vibration between the battery pack, BMS board, and outer enclosure walls.

Technical Specifications:

• Configuration Fit: 4-Cell (4S / 4P) 18650 Battery Pack Face
• Profile Type: Solid (Unperforated Continuous Sheet)
• Material: Electrical-Grade Highland Barley Paper / Vulcanized Fish Paper
• Adhesive Type: High-Tack Single-Sided Acrylic Pressure-Sensitive Adhesive
• Dielectric Breakdown Strength: ≥ 3.0 kV/mm
• Continuous Temperature Rating: -30°C to +120°C

Mechanical Specifications:

• Thickness: ~0.20 mm to 0.25 mm
• Color: Matte Green / Cyan-Green
• Application: Peel-Off Release Liner

Dimensions:

• Length: ~74 mm (4 × 18.5mm Cell Pitch)
• Width: ~18 mm (Single-Row 4S) or ~37 mm (2×2 4S Pack)
• Thickness: 0.25 mm
• Weight: ~2 g

Pinout and Wiring:

• Post-Weld Insulation: Peel off the backing paper and press the solid gasket directly over the completed nickel strip welds on the top and bottom of your 4S 18650 pack before shrinking the outer PVC sleeve.
• BMS Under-Pad Isolation: Stick a solid gasket between the cell cans and the underside of your 4S BMS protection board to prevent solder joints from rubbing through cell wraps.

Datasheet Reference:

• Insulation Class: Class E / Class A Electrical Insulating Fish Paper (IEC 60641)

Commonly Used in:

• 4S (14.8V / 16.8V) 18650 Lithium-Ion Battery Pack Assembly
• BMS Protection Board Under-Layer Dielectric Isolation
• Power Tool, E-Bike, and Robotics Battery Rebuilds
• Spot-Welded Nickel Strip Terminal Capping

Applications:

• Seals and insulates exposed nickel strips on the ends of a 4S 18650 battery pack prior to enclosing in heat-shrink tubing or a hard plastic case.
• Provides a tough, puncture-proof barrier beneath a 4S BMS board or balance wires.
• Prevents catastrophic short circuits caused by vibration or sharp nickel weld burrs.

Equivalent Models:

• 4S 18650 Battery Hollow Barley Paper Positive Insulating Gasket: Ring-cutout (hollow) version applied to individual 18650 positive caps BEFORE spot welding.
• 1×1 / 2×1 / 3×1 18650 Li-Ion Battery Cell Interlocking Spacer Holder: Rigid ABS+PC plastic cell brackets for structural pack alignment.

Package Includes:

• 1 × 4S 18650 Battery Solid Barley Paper Insulating Gasket