Semifuse SFSR Resettable PTC Fuses

Semifuse SFSR series re-settable polymer PTC fuses are the industry standard from the leading manufacturer Fuzetec.  These strap PTC fuses will provide reliable, non-cycling protection against short circuits or other over-current conditions in primary or secondary (rechargeable) batteries.

Once tripped, the PTC fuse remains in a high resistance state until the fault is removed, preventing any potential damage to the battery.  The thin strap format allows the fuse to be directly welded as a link between adjacent cells in NiMH and Li-ion battery packs.  Space in the battery design must be left for a small thermal expansion of the fuse during its tripped state.


  • Rechargeable battery packs
  • Lithium cells
  • Battery packs


  • Voltage ratings; 15VDC to 30VDC
  • Current ratings; 1.2A to 4.2A
  • Temperature range;  -40°C to 85°C
  • Nickel straps for spot-welding between battery cells
  • Low-profile design
  • Solid-state function
Range of PPTC resettable fuses from ATC Semitec

Dimensions Table

SFSR Data Table