DETROIT -- Japanese supplier Denso Corp. said it has developed a lithium ion battery pack to boost fuel efficiency of vehicles with stop-start systems.
The new battery pack allows the stop-start system to use more regenerative power than conventional systems that use a single lead-acid battery, the Toyota-affiliated supplier said Wednesday.
Stop-start systems save fuel by turning off the engine at a complete stop and restarting it when the driver’s foot leaves the brake.
Denso’s lithium ion battery pack comes in the Suzuki Wagon R, which Suzuki Motor Corp. launched this month in Japan.
A Denso spokeswoman today declined to name any other automakers planning to use the battery pack.
Denso’s pack stores regenerated power, then supplies it to electrical and electronic components such as navigation and audio systems. This reduces the power generation needed by the alternator, resulting in an overall load reduction on the engine and improving fuel economy.
Because the battery pack is naturally air-cooled, it doesn’t need a dedicated cooling system. This allows for the 5.5-pound pack to be lighter and more compact, giving automakers more packaging design flexibility.
The Denso battery pack has a management unit that monitors and controls the voltage of the battery cells to maintain proper charge level and protect from overcharging and discharging too much.
In addition, a power supply control switch controls the charging of the battery cells by the energy captured during deceleration and braking. It also controls the amount of power supplied to the vehicle’s navigation, audio and other systems while driving.
Denso, of Kariya-Aichi, Japan, ranks No. 2 on the Automotive News list of the top 100 global suppliers with estimated worldwide parts sales to automakers of $34.2 billion in fiscal 2011. The company is 24.7 percent owned by Toyota Motor Corp.