Li-ion battery management ICs - 21 February 2018 - Hi-Q Electronics

Li-ion battery management ICs
21 February 2018, Power Electronics / Power Management

Renesas Electronics rolled out two new battery management IC solutions for lithium-ion (Li-ion) rechargeable batteries used in industrial equipment, such as electric power tools and E-bikes (bicycles incorporating electric motors). The solutions based on the RAJ240090, supporting three to eight cells, and RAJ240100, supporting three to 10 cells, simplify the design of industrial battery management systems, providing a high degree of safety.

The new solutions support up to 10 cells for a maximum 50 V capability and are Renesas’ first battery management solutions for Li-ion batteries supporting industrial applications. The RAJ240090 and RAJ240100 have built-in safety features to protect Li-ion batteries from catastrophic failure. In addition, Renesas offers design support tools, which enable the rapid development of battery management systems.

Featuring an integrated RL78 MCU (microcontroller), the ICs integrate the remaining capacity measurement and safety monitoring functions, such as over-voltage and over-current, into a single package. This provides a high-precision analog-to-digital converter (required for battery control voltage measurement) and MCU that have been matched and adjusted beforehand, thereby contributing to substantially reducing the need for calibration. In addition, the peripheral functions required by industrial applications, including power supply, field effect transistor (FET) driver and real-time clock, are included on-chip.

The RAJ240090 and RAJ240100 support an ultra-low-power mode, which reduces current consumption to only 25 μA. This allows battery monitoring functions to operate constantly, even when the system is powered off. A record-keeping function can store information such as battery history to monitor deterioration and store system faults in the MCU memory. The MCU can issue an alarm and disable the battery to prevent Li-ion battery failure.

In addition, the battery management ICs support a system configuration in which N-channel MOSFETs are positioned at the positive poles of the battery cells. This means that if the battery management IC fails, the system can be shut down safely. If, on the other hand, the MCU enters a runaway state, the battery protection function of the analog front-end block can continue to operate independently, providing a failsafe for enhanced system safety.

Renesas plans to release development startup support tools, such as reference software, reference circuit diagrams and setup manuals. The support tools will enable changes to parameter settings and simplify Li-ion battery pack design, and enable faster solutions for battery management.

For more information contact Callie Lombard, Hi-Q Electronics, +27 (0)11 894 8083, callie@hi-q.co.za, www.hi-q.co.za