LR4 Series - 15/20 V PolySwitch Lead Free Battery Strap PPTC - 125C Activation Temperature

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Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their own applications. Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. "Littelfuse" includes Littelfuse, Inc., and all of its affiliate entities.

As a pioneer of polymeric positive temperature coefficient resettable devices, Littelfuse has developed several material platforms to serve the changing battery technology and to help protect battery applications. Each of these material platforms offers different performance characteristics, allowing engineers greater design flexibility. PolySwitch devices for battery protection include SRP, LR4, VTP, VLP, VLR, MXP and RSD series, and special application strap devices.


  • RoHS compliant
  • Lead-free versions of all devices are available.
  • Current ratings from 1.1A to 13A
  • Fast time-to-trip


  • Many material platforms and device form factors give engineers more design flexibility
  • Compatible with high-volume electronics assembly
  • Assists in meeting regulatory requirements
  • Low resistance devices increase battery operating time


  • Mobile phones and smart phones
  • Tablet PCs
  • Ultra-thin notebooks
  • Mobile radios
  • Digital cameras
  • Portable media players
  • Power tools (charge lines)

Access specifications, certifications, check availability and order parts below

Catalog #IHold (A)ITRIP
Max Volts
Trip Time
Activation Temp (Deg C)Interrupt Current (A)Max Operating Temp (°C)Product
Partner ECAD ModelsStockSamplesCompare
LR4-1300SSF1321.2201004.50.00350.00650.009100.006125100Not ApplicableProduct SpecificationLR4-1300SSFCheckOrder
LR4-190F1.93.9151001.20.0390.0720.10250.056125100Not ApplicableProduct SpecificationLR4-190FCheckOrder
LR4-260F2.65.8151002.50.020.0420.06350.031125100Not ApplicableProduct SpecificationLR4-260FCheckOrder
LR4-380F3.88.3151002.50.0130.0260.03750.0195125100Not ApplicableProduct SpecificationLR4-380FCheckOrder
LR4-380XF3.88.3151002.50.0130.0260.03750.0195125100Not ApplicableProduct SpecificationLR4-380XFCheckOrder
LR4-450F4.58.9201002.30.0110.020.02850.016125100Not ApplicableProduct SpecificationLR4-450FCheckOrder
LR4-550F5.510.5201002.80.0090.0160.02250.013125100Not ApplicableProduct SpecificationLR4-550FCheckOrder
LR4-600F611.7201002.80.0070.0140.01950.0105125100Not ApplicableProduct SpecificationLR4-600FCheckOrder
LR4-600XF611.7201002.80.0070.0140.01950.011125100Not ApplicableProduct SpecificationLR4-600XFCheckOrder
LR4-730F7.314.1201003.30.0060.0120.01550.009125100Not ApplicableProduct SpecificationLR4-730FCheckOrder
LR4-900F916.7201003.80.0060.010.01450.008125100Not ApplicableProduct SpecificationLR4-900FCheckOrder
Part # Part Description RoHS Pb-free RoHS (2015/ 863/EU) Certificate REACH (SVHC’s) Declaration Halogen Free REACH (SVHC’s) IPC-Material Declaration
RF1550-000 LR4-1300SSF RoHS No 07/02/2018 PbFree No 07/02/2018 CoC_RoHS10_RF1550-000_LR4-1300SSF REACH209_Declaration_RF1550-000_LR4-1300SSF No
Does not Contain
RF1538-000 LR4-190F RoHS No 01/11/2017 PbFree No 01/11/2017 CoC_RoHS10_RF1538-000_LR4-190F REACH219_Declaration_RF1538-000_(LR4-190F) Yes
Does not Contain
RF1543-000 LR4-260F RoHS No 02/20/2017 PbFree No 02/20/2017 CoC_RoHS10_RF1543-000_LR4-260F REACH205_Declaration_RF1543-000_LR4-260F No
Does not Contain
RF1536-000 LR4-380F RoHS No 08/09/2017 PbFree No 08/09/2017 CoC_RoHS10_RF1536-000_(LR4-380F) REACH211_Declaration_RF1536-000_(LR4-380F) Yes
Does not Contain
E89591-000 LR4-380XF RoHS No 09/01/2019 PbFree No 09/01/2019 CoC_RoHS10_E89591-000_(LR4-380XF) REACH219_Declaration_E89591-000_(LR4-380XF) Yes
Does not Contain
RF1542-000 LR4-450F RoHS No 10/27/2017 PbFree No 10/27/2017 CoC_RoHS10_RF1542-000_(LR4-450F) REACH205_Declaration_RF1542-000_LR4-450F No
Does not Contain
RF1545-000 LR4-550F RoHS No 06/13/2017 PbFree No 06/13/2017 CoC_RoHS10_RF1545-000_LR4-550F REACH219_Declaration_RF1545-000_(LR4-550F) No
Does not Contain
RF1549-000 LR4-600F RoHS No 01/11/2017 PbFree No 01/11/2017 CoC_RoHS10_RF1549-000 REACH191_Declaration_RF1549-000_(LR4-600F) Yes
Does not Contain
A77736-000 LR4-600XF RoHS No 06/13/2017 PbFree No 06/13/2017 CoC_RoHS10_A77736-000_LR4-600XF REACH209_Declaration_A77736-000_LR4-600XF Yes
Does not Contain
RF1547-000 LR4-730F RoHS No 06/13/2017 PbFree No 06/13/2017 CoC_RoHS10_RF1547-000_LR4-730F REACH219_Declaration_RF1547-000 (LR4-730F) Yes
Does not Contain
RF1534-000 LR4-900F RoHS No 08/22/2017 PbFree No 08/22/2017 CoC_RoHS10_RF1534-000_LR4-900F REACH219_Declaration_RF1534-000_(LR4-900F) No
Does not Contain
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