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BTMS S1

The S1 is a high-capacity, AC-powered battery thermal management system delivering precise cooling and heating to maximise battery life, efficiency, and performance.

Ideal for constant-load applications such as battery energy storage systems, it provides stable, reliable thermal control in high and low ambient conditions.

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Overview

The BTMS S1 is designed for stationary power and heavy EV platforms operating on AC power, delivering stable, continuous battery thermal management in a compact unit. It maintains battery temperature within a tightly controlled range using integrated active cooling and electric heating.

Powered by Grayson’s Intelligent Thermal Controller and proprietary control logic, the system communicates via CAN J1939 for seamless integration. It continuously monitors coolant temperature and automatically selects the appropriate thermal mode to protect battery health, optimise charging, and maintain performance.

Operating on a 400V AC three-phase supply, with 24V DC for controls, fans, and pumps, the S1 provides 14kW cooling and 5kW heating. Compliant with EN-12663-1:2015 shock and vibration standards, it supports chassis, roof, or body mounting for flexible installation.

Features

Our variations include features designed to maximise performance, improve efficiency, and simplify integration.

  • High-capacity thermal performance: Delivers 14kW cooling and 5kW heating to meet demanding battery thermal needs in varied climates.
  • Integrated all-in-one design: Refrigerant circuit, pump, heater, fans, and controller housed in a single package for ease of installation.
  • Proprietary thermal control logic: Grayson’s Intelligent Thermal Controller with CAN J1939 interface enables precise, responsive thermal regulation.
  • AC-powered for constant-load applications: 400V AC 3-phase power supply ensures stable operation for stationary and continuous-duty environments.
  • Easy software management: CAN bootloader for field updates and DM1 diagnostic messaging for efficient servicing.
  • Long-life brushless fans and pump, scroll compressor: Delivers high efficiency, low noise, and extended service life for reduced downtime and lower TCO.
  • Validated, homologated, and certified: Fully tested for performance, durability, and compliance, including EMC R10 certification, ensuring suitability for global markets.
  • Durable and compliant: Meets EN-12663-1:2015 shock/vibration standards, with anti-vibration mounts supplied as standard
  • 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.
Technical

Each technical component contributes to stable battery temperatures, supporting safety, efficiency, and extended battery life.

  • Cooling capacity: up to 14kW
  • Electrical heating capacity: 5kW
  • Ambient temperature range: -30°C to +45°C
  • Dimensions: 1319mm x 556mm x 392mm (L x W x H)
  • High Voltage supply: 400V AC 3-phase 50Hz
  • Low Voltage supply: 24V DC
  • Refrigerant: R407C
  • Coolant type: 50/50 water/ethylene glycol mix
  • Weight: Approx. 92kg (excluding coolant)
  • Control: CAN J1939 control interface with diagnostics
  • Mounting: Chassis or roof mount
Model Variations

The range is available in multiple models to meet diverse vehicle heating needs and installation requirements.

3A-6726-XXXX - Active Cooling, Passive Cooling and Heating

3A-6728-XXXX - Active Cooling and Heating     

Heating Capacity

5kW electric water heating

Ensures battery pre-conditioning and performance in cold environments.
Power Supply

400V AC 3-phase input

Stable thermal control for stationary power and heavy EV applications running on AC power.
Intelligent Control

Proprietary GTS logic

Enables precise thermal regulation, configurable set points, and CAN J1939 integration.
Cooling Capacity

Up to 14kW active cooling

High-capacity thermal control for large battery systems under high-load or high-ambient conditions.
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Compatible Applications

Product Benefits​

Discover why heavy vehicle and BESS OEMs rely on the Grayson S1 BTMS to control their batteries’ thermal management.

Extended Battery Life

Maintains optimal operating temperature for improved efficiency and reduced degradation.

Built for AC-Powered Platforms

Direct AC supply ensures efficient, reliable performance for continuous-duty operations.

Reduced Installation Time

All-in-one, plug-and-play package for quick installation and commissioning.

Reliable in Harsh Conditions

Built to withstand extreme temperatures and mechanical vibration.

Contact Us

Looking for more information about our thermal management products, aftermarket parts and servicing, or need technical support from one of our expert engineers? Complete the form below and we will respond as soon as possible.

Enquire About Our S1 BTMS Today

Also in the Range

Discover more battery thermal management systems in the Grayson range.
BTMS Case Study

See the S1 in action

See how the Grayson S1 BTMS helped leading European locomotive OEM, Bemo Rail, manage the thermal demands of their new hybrid application. View Case Study
Our Capabilities

Require a Custom BTMS?

If your application demands a custom approach, we work with you from concept to manufacture to create a BTMS tailored to your exact requirements. Learn More

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Discover More About Grayson

Drawing on over four decades of expertise, Grayson Thermal Systems designs and delivers innovative thermal management solutions for vehicles worldwide. Our products and support services are built to ensure lasting efficiency and dependable performance.