Sensata Unveils a Battery Management System for 60-Volt Applications

The i-BMS Battery Management System, a compact, cell chemistry agnostic, integrated BMS, was developed by Lithium Balance, a company acquired by Sensata earlier in the year. It is aimed at the cost-optimized mass-production of applications of up to 60V, such as light electric vehicles (LEVs), and can monitor as many as 15 battery cells in series.

Sensata’s i-BMS was recently displayed at the Battery Show North America. Image courtesy of Sensata

The i-BMS is a complete solution aimed at managing and maintaining battery systems without any need for any ancillary components. The unit features an integrated pre-charging circuit, current measurement capability,  a DC/DC power supply as well as MOSFET power switches to enable battery disconnect.

 

Critical Capabilities

The i-BMS features a dual-core lockstep CPU and an ASIL C-compliant ASIC. It can measure battery cell temperature with an accuracy of +/-1 °C and cell voltage to within +/- 1.6 mV over a temperature range of -10 to +70 °C.

The device’s software design allows for parallel pack and hot-swap capability. Using the company’s BMS Creator configuration software, the i-BMS enables battery designers to devise new batteries by defining application-specific parameters, thereby optimizing battery performance and life.

 

Sensata’s Acquisition of Lithium Balance

Sensata, long a provider of sensors and sensor-based solutions such as controllers and software, acquired Gigavac in 2018. The combined entity was well-positioned as a provider of high voltage protection on EVs and in the charging infrastructure. The acquisition of Lithium Balance, the initial developer of the i-BMS early in 2021, extends Sensata’s reach into the closely related area of battery management solutions. This new combined entity will benefit from Sensata’s extensive customer base of large OEMs and from Lithium Balance’s industrial relationships and technology.

Lithium-ion batteries (LiBs) are composed of many individual battery cells and are a critical concern to manufacturers. The heath and functionality of each cell must be constantly monitored, and they must be balanced in relation to each other.

This is an especially critical concern for electric vehicles (EVs), largely because LiB’s are their most problematic systems. We recently covered Volkswagen’s choice of NXP to manage its vehicles’ onboard LiBs and GM’s choice of Analog Devices for a similar role. Clearly, the “care and feeding” of LiBs is and will continue to be a key concern in the ongoing worldwide trend of electrification, of which Sensata is now a part.

As described by Vineet Nargolwala, Executive Vice President, Sensing Solutions at Sensata Technologies, says, “We are pleased that the talented Lithium Balance team is now part of Sensata. We have already seen great benefits from our close collaboration in developing common technology solutions for the benefit of our customers. The acquisition enables us to deliver more comprehensive battery management solutions across a wide range of electrification applications in a variety of industrial and transport markets.”

 

Major Specifications

Battery Life

• Sampling of cell voltage, current and temperature every 100ms
• Intelligent passive balancing at 200mA per cell

Performance

• State of charge (SOC) accuracy of ±3%
• State of health (SOH) accuracy of ±2% point from 80% SOH
• Auto-off/sleep mode for low power consumption in idle mode

Communication

• Via Controller Area Network (CAN) bus

Current Capability

• 100 amps maximum without cooling
• 150 amps peak for 10 seconds

 

Applications

Applications of up 60 volts, including:

• 2-wheelers and 3-wheelers
• Automated guided vehicles (AGVs)
• Robotics

 

Physical

• The i-BMS measures 65 x 200mm