Grayson Generation 3 Battery Thermal Management System

BTMS Generation 3 (Gen 3) is now available for Bus, Coach, Off-Highway, and Commercial vehicles.

We also have a BTMS product range suitable for the Rail sector designed and developed to meet the stringent compliance requirements for operation in rail.

What is a Battery Thermal Management System?

Our Battery Thermal Management System (BTMS) regulates the temperature of electric vehicle batteries, providing temperature control that is critical to their function and operational life.

The Battery Thermal Management Systems (BTMS) have heating and cooling capabilities to maintain the battery cell temperature within the specified range. The system, controlled by Grayson Thermal Systems smart controller reacts to the cell temperature. Our BTMS offers cooling during fast charge periods or high ambient territories. Heating following a period of sustained low ambient in cold climates.

Grayson Thermal Systems have a standard range of rooftop-mounted modules and bespoke integrated systems packaged into the vehicle chassis and body.

Why Choose Grayson Thermal Systems GEN3 BTMS?

We’ve made extensive advancements in our BTMS range since we launched our GEN1 BTMS in 2015. Taking all of the know-how we have developed over the years designing and delivering BTMS across the globe, our BTMS Generation 3 range (GEN3 45 BTMS and GEN3 50 BTMS) has numerous benefits, including:

  • Optimises battery efficiency and life
  • Adapts to ambient temperature
  • ‘Plug and Play’ easy installation
  • CAN Bootloader for easy software updates
  • DM1 diagnostics messaging broadcast on the CAN network
  • Production in 4 manufacturing plants
  • We’re specialists in the transportation industry
  • Designed with Grayson’s extensive knowledge & expertise
  • Exceptional service and product support
  • Guaranteed reliability through product durability testing
  • Lightweight to fit your needs




  • Flexible bespoke solutions for maximum compatibility
  • Quick Connection Plug & Play to reduce installation time and cost
  • Fully integrated components maximising efficiency
  • High capacity heating capability offering rapid warm up allowing batteries to reach operating temperature quickly
  • Energy saving passive ambient cooling
  • Active refrigerant cooling allowing tropical cooling capacity
  • Brushless fans, scroll compressor, brushless pump provide long life & reliable performance
  • Compact unit offering 3 step thermal management systems – Heating / Passive Cooling / Active cooling
  • Efficient energy consumption while maximising cooling performance


  • Smart control logic operating J1939 with CAN standard
  • Compressor options: 600V DC (400V DC – 720V DC)
    400V / 50Hz / 3 ph
    200V / 60Hz / 3 ph
  • Built in aluminium header tank with coolant level sensor or switch
  • Refrigerant R134a (optional R407C) ready with new
    ODP/GWP refrigerants
  • Compact unit with complete thermal management system
  • This system is delivered fully charged with refrigerant


GTS BTMS regulates the temperature of electric vehicle batteries, providing temperature control that is critical to their function and operational life. With further advancements in features and benefits, our Gen3 BTMS can be used across a wide range of applications and markets around the world.

To maximise cell life, the battery manufacturers want to hold the battery at a constant temperature regardless of ambient, for example heating will operate in ambient of -30°C up to 15°C, Passive cooling will operate in an ambient of 0°C up to 20°C and active cooling will operate in an ambient 20°C up to 40°C (50°C on tropical applications).

Equally the batteries need to rise above 5°C as quickly as possible because they do not operate efficiently below this value.

Technical Specifications