DENSO Corporation has developed, together with Toyota Motor Corporation, a new power supply management electric control unit (ECU) for the Lexus LS460. The Lexus LS460 was launched in Japan this month.
"In recent years, vehicles require more electric power due to various safety and information systems," said Mineo Hanai, senior managing director, responsible for Electric Systems Business Group. "In response to the growing need for more electric power, we developed the new power supply management ECU".
The ECU calculates the battery charge rate and internal resistance using battery voltage and current. When the battery charge rate is low, the ECU increases the alternator's adjustment voltage for generating electricity or raises the engine revolutions during idling to stimulate battery charging.
Based on the information about the voltage and internal resistance of the battery, the ECU also determines which system the electric power should be preferentially supplied to when the battery charge rate is low or when the alternator malfunctions. In these situations, the ECU will reduce electric power delivered to such components as the seat heater, for example, in order to ensure enough power for safety systems such as the pre-crash safety system.