Denso’s new lithium-ion battery pack for Stop/Start System helps further increases fuel efficiency

October 4, 2012: Denso Corporation has developed a lithium-ion battery pack that further increases the fuel efficiency of vehicles with stop/start systems. The new battery pack allows the stop/start system to use more regenerative power than current conventional systems that use a single lead-acid battery. The battery pack consists of a battery management unit and power supply control switch, as well as battery cells that are provided by a third-party source. The battery pack stores regenerated power and then supplies the stored regenerated power to the electrical and electronic components, such as the car navigation and audio systems. This reduces the power generation required by the alternator, which results in an overall load reduction on the engine and improves the vehicle’s fuel economy.

The 2.5kg unit (L/W/H: 200/178/ 70mm) unit is naturally air-cooled and therefore does not require a dedicated battery cooling system. Because there is no need for auxiliary cooling components, this allows the battery to be lighter and more compact, and enables automakers more design flexibility, which is important for vehicles with limited space.

Denso has developed different types of starters to meet the specific OEM needs for their stop/start systems, including the Advanced Engagement (AE) Starter, Permanently Engaged (PE) Starter, and Tandem Solenoid (TS) Starter. It has also developed a Cold Storage (CS) Evaporator which increases the effectiveness of idle-stop, particularly at high temperatures.

Photograph: Cutaway model of the lithium-ion battery pack