The BTMS M1 maintains liquid-cooled traction batteries at optimal temperatures in battery-electric and fuel-cell-electric vehicles, maximising cell life, charge efficiency, and performance.

Controlled by Grayson’s proprietary thermal logic software via CAN J1939 – and including a built-in Grayson Intelligent Control Module, the M1 continuously monitors coolant temperature and activates active cooling, passive cooling, or electrical heating as required.

Its integrated brushless motor pump and fan, lightweight header tank, and compact footprint make it ideal for rooftop, chassis, or body-mounted applications in space constrained environments.

Available in high voltage options up to 900V DC, it supports modern platforms.

Proven globally, the M1 offers configurable performance for extreme climates, fast charging, and cold-weather operation.

Discover the key features that make our thermal solutions reliable, efficient, and built for long-term performance.

• Configurable thermal control modes: Active cooling, passive cooling and/or heating.
• Adapts to ambient temperature and coolant set-point: Optimises performance based on ambient temperature and target coolant set-point.
• Bespoke temperature set-point and CAN addresses: Factory-configured to each customer’s operating requirements for seamless integration.
• Battery pre-conditioning capability: Electrical heating supports cold-weather performance.
• CAN J1939 bootloader for easy software updates: Enables in-field firmware updates without disassembly.
• DM1 diagnostics on CAN J1939 network: Broadcasts fault codes and status messages for simplified troubleshooting and maintenance.
• Wide high-voltage range: Operates from 420V to 756V DC, with 900V DC capability available, supporting present and next-generation BEV and FCEV platforms.
• Integrated components for simplified installation: Brushless water pump, lightweight header tank, electric expansion valve, and brushless fan are all housed within the unit.
• Long-life brushless fans and pump, scroll compressor: Delivers high efficiency, low noise, and extended service life for reduced downtime and lower TCO.
• Compact and lightweight design: Optimised for space-constrained installations.
• Validated, homologated, and certified: Fully tested for performance, durability, and compliance, including EMC R10 certification, ensuring suitability for global markets.
• Worldwide aftersales service and product support: Backed by Grayson’s global aftermarket network for parts, technical assistance, and service expertise.
• Global manufacturing capability: Produced across four plants worldwide for supply chain resilience and shorter lead times.

Engineered for performance and reliability, our system incorporates a range of advanced features designed to meet the demanding requirements of modern applications.

• Cooling capacity: up to 5.8kW @ 40°C ambient, 25°C coolant outlet, 40l/min flow
• Dimensions: 750mm x 604mm x 438mm (L x W x H)
• Electrical heating capacity: 3.6 kW standard 
• Voltage range: 420V to 756V DC as standard - 900V DC capability available
• Refrigerant: R134a / R407C (optional)
• Coolant type: 50/50 W.E.G
• Weight: Approx. 55kg (excluding coolant)
• Control: CAN J1939 control interface with diagnostics
• Mounting: Suitable for roof, chassis, or body mounting

Available in a range of model options, our product line offers configurations to suit performance needs and installation requirements.

• 3A-6720-0A00 – 600V DC: Active Cooling, Passive Cooling and Heating
• 3A-6720-0B00 - 600V DC: Active Cooling and Passive Cooling Only
• 3A-6720-0C00 - 600V DC: Active Cooling and Heating
• 3A-6720-0D00 - 600V DC: Active Cooling Only

*Contact Grayson today to learn more about 900V DC options