XPAND Direct Liquid Cooled Battery ModuleXPAND Direct Liquid Cooled Battery ModuleThe performance, safety and cost of ownership of an energy storage system depend not only on the quality of the cell itself, but on how well the other parts of the system work together in demanding environments.

We have brought together high-skilled mechanical, electrical, thermal and software engineers, world-class manufacturing capabilities, and a powerful commitment to customer support to help create energy storage systems that help power your innovation. Through our engineering process we evaluated over 2,000 different sets of requirements from multiple industries in order to develop a robust building block with customizable features that allow optimized system solutions.


Introducing the XPAND Family of Energy Storage Systems

The XPAND Modular Pack (XMP) and the XPAND Modular Pack Plus (XMP+) are XALT Energy’s state of the art Energy Storage Systems (ESS) based on XALT Energy’s world class lithium-ion cell designs. XMP is designed for use in multiple applications including hybrid and electric commercial truck, bus and heavy duty transportation; hybrid and electric marine power and propulsion, and grid and stationary applications.

XPAND High Voltage Energy Storage System (ESS) StringXPAND High Voltage Energy Storage System (ESS) String


The XMP cores are designed to accommodate all XALT cells in the 216mm and 255mm families without the need for retooling, anticipating a wide variety of application voltages, powers, and energies. The XMP packs also integrate the flexibility to be used individually or to be strung together in series and parallel to create large high voltage systems.

Customizable Solutions

The new “variable bulkhead” concept allows the XALT engineering team to customize each XPAND ESS for each customer without having to redesign the entire system. 

Advanced Thermal Management

XMP utilize an advanced, active liquid cooling system that enables the pack to maintain consistent cell temperatures throughout the pack and to respond quickly to increases in temperature. No need for bulky air plenums, noisy fans, conditioned air, and costly filter maintenance.  Energy efficient direct liquid cooling prolongs cell life under the most demanding cycle.

Performance  Characteristic





Product Availability


Q4 '16

Q1 '17

Q4 '17

XALT Lithium-ion Cell


40Ah HE

45Ah HE

56Ah HE

Pack Configuration

P / S

2P 24S

2P 24S

2P 24S

Capacity (Rated @ C/2)





Voltage (Nominal)





Discharge Energy (C/2)










Specific Energy





Volumetric Energy Density





Dimensions (all versions incl base)


(L) 753

(W) 303

(H) 282

XPAND® Modular Pack (XMP) – For Transit / Marine / Grid pdf


Battery Management System (BMS)

Voltage & temperature parametric management example performed by XALT BMSVoltage & temperature parametric management example performed by XALT BMS

The BMS is the “brains” of the XMP system providing the monitoring, balancing and safety functionality for the system. 

The main job of the BMS is to maintain the Lithium-ion cells within their safe operating range regardless of the demands being placed on them. This means the ability to accurately predict operating situations that have the potential for creating over-voltage or  under-voltage conditions, as well as high or low temperature conditions – then reacting quickly and safely to prevent those conditions from occurring.

Battery Management System (BMS) pdf


Comprehensive System Level Testing of XPAND Packs & BMSComprehensive System Level Testing of XPAND Packs & BMSPrimary BMS Controller Functions:

  • Monitors and controls SOC, SOH, Internal resistance measurement and the maximum allowable current (in charge and discharge modes)
  • Performs battery charge management (current set point)
  • Actively manages cell balancing (resistive)
  • Performs battery thermal management
  • Monitors for over voltage, low voltage, over current and fault detection
  • Manages degraded modes, ensuring system and user safety
  • Provides diagnostics and remote monitoring capability

BDU/SCU (Battery Disconnect Unit/String Control Unit)

  • XALT Energy Battery Disconnect Unit/String Control UnitXALT Energy Battery Disconnect Unit/String Control UnitManages one (1) string of sub-packs per system
  • Includes HV contactors, current sensing and pre-charge circuit
  • Measures the HV insulation resistance between the battery system and ground
  • Voltage monitoring and SoC calculation
  • Communicates through J1939 CANBus to the application or MCU when there is more than one (1) string for control
  • Supports diagnostic services for reprogramming and calibration
  • Contributes to the functional safety of the battery system



To learn how XALT Energy’s system solutions can help meet your needs, contact us.