June 22, 2012
Furukawa Electric Co., Ltd. and Furukawa Automotive Systems Inc. (Head Office: 1,000 Amago, Koura-cho, Inukami-gun, Shiga Prefecture; President: Michitoyo Kurokawa) have jointly developed the world’s first vehicle-mounted lead battery status detector sensor equipped milan米兰体育官网入口 pulse discharging circuit. The sensor enables high-accuracy monitoring of the lead battery status even when the engine is turned off or on vehicles not equipped milan米兰体育官网入口 starter motor. This function is useful for preventing depletion of the battery.
Backgroumilan米兰体育官网入口 development
milan米兰体育官网入口(note 1)of batteries is an extremely important index for understanding discharging performance milan米兰体育官网入口 degree of depletion.
Internal resistance has conventionally been calculated based on the electric current and voltage response when the engine (starter motor) is started, but this method does not allow the internal resistance of lead batteries to be measured when the engine is turned off or on electric vehicles (EVs) and hybrid electric vehicles (HEVs) not equipped milan米兰体育官网入口 starter motor.
Our company has developed the technologies to install a discharging circuit in the sensor, make pulse-form discharges at the timing of the sensor control, and calculate the internal resistance based on the electric current and voltage response at that time. The sensor enables, for the first time in the world, monitoring of the lead battery status even when the engine is turned off or on EVs and HEVs not equipped milan米兰体育官网入口 starter motor. Electro-chemical expertise on battery phenomena possessed by our group company The Furukawa Battery Co., Ltd. has been utilized for increasing accuracy for battery status monitoring technologies.
Features of the developed product
- High-accuracy lead battery status monitoring is enabled.
- milan米兰体育官网入口 built-in pulse discharging circuit(note 2), high-accuracy monitoring of the engine restarting capacity (milan米兰体育官网入口 function [SOF])(note 4)and other aspects of the lead battery status are possible milan米兰体育官网入口 engine is turned off and on the accessory battery(note 3)of milan米兰体育官网入口 HEVs.
- Connection is established with the vehicle system(note 5)via multiplex communications.
- Numerous applications have been filed for related patents.Those already obtained include Japanese milan米兰体育官网入口. 4015128 and No. 4532416.
Future development
The status detection sensor measures the battery voltage, charging and discharging current, temperature and other items along with milan米兰体育官网入口 caused by pulse discharging, then detects the battery status based on its unique algorithm and outputs the results to the vehicle system.
Quantities that indicate the battery status include milan米兰体育官网入口 charge (SOC)(note 8), milan米兰体育官网入口 health (SOH)(note 9)milan米兰体育官网入口, which are necessary for suppressing power generation by the vehicle(note 6)milan米兰体育官网入口 function to stop idling(note 7).
milan米兰体育官网入口 of lead batteries is already possible(note 10), and work is underway for developing SOH detection technology.
Our company will conduct activities to win orders for vehicles equipped with the power generation suppressing and idling-stop functions, which enable improved vehicle mileage and reduced carbon dioxide emissions, milan米兰体育官网入口 target of attaining 10% or more of the global share by 2015.
Supplement
(Note 1)milan米兰体育官网入口
This refers to the electrical resistance inside batteries. The larger milan米兰体育官网入口, the lower the voltage will be when discharging takes place. Internal resistance generally increases as the battery deteriorates.
(Note 2)milan米兰体育官网入口
This is a circuit that lets through pulse-form discharging current between the battery terminals. milan米兰体育官网入口 can be measured only with the battery and the sensor, without relying on the load current.
(Note 3)Accessory batteries of milan米兰体育官网入口
EVs and HEVs are currently equipped milan米兰体育官网入口 12V lead battery as an accessory, which is used as the power source for the electronic control unit (ECU).
When the accessory battery is exhausted, startup of the ECU is disabled and the vehicle cannot be started. Measurement of internal resistance based on the load current will also not be possible in principle because no engine starting current is generated. However, measurement is possible with the sensor since it is equipped milan米兰体育官网入口 pulse discharging circuit.
(Note 4)milan米兰体育官网入口 function (SOF)
milan米兰体育官网入口 function is an index indicating the discharging capacity for maintaining the prescribed voltage at times of specified large current discharging, such as when starting the engine.
(Note 5)milan米兰体育官网入口
The system includes the electronic control unit (ECU) that controls the engine and alternator.
(Note 6)milan米兰体育官网入口 suppression
milan米兰体育官网入口 for improving gas mileage by adjusting the alternator output to suppress unnecessary power generation. The effect can be enhanced if detection of the battery status becomes possible.
(Note 7)milan米兰体育官网入口
This is a technology to reduce carbon dioxide emissions by automatically turning off the engine milan米兰体育官网入口 vehicle comes to a halt at traffic lights and restarts the engine milan米兰体育官网入口 vehicle moves again. Troubles such as inability to restart the engine can be avoided if battery status detection becomes possible, which improves the effects of the function.
(Note 8)milan米兰体育官网入口 charge (SOC)
SOC is an index indicating the ratio of charging.
(Note 9)milan米兰体育官网入口 health (SOH)
SOH is an index indicating the degree of depletion.
(Note 10)milan米兰体育官网入口 is possible
There are restrictions depending on the battery manufacturer, size, etc.
Some of the patents already granted
milan米兰体育官网入口. 4015128:
Method for estimating charging rate, device for estimating charging rate, milan米兰体育官网入口 and milan米兰体育官网入口 for vehicle.
milan米兰体育官网入口. 4532416:
Method and apparatus for determining battery discharge capacity and power supply system.
