Denso Corporation

Nippon Soken, Inc.

Shigenori Saito

Naoki Katayama

Hiroshi Tamura

Atsushi Imai

Teruhiko Kameoka

Satoru Mizuno

Toshiyo Teramoto

Kenji Ueda

Shunichi Maeda

Takao Suenaga

An electric power source system for a vehicle includes a lead-acid battery electrically connected with the starting device in parallel as a first storage battery, a second storage battery electrically connected with the starting device in parallel, a switch device disposed between the lead-acid battery and the second storage battery on an electrical path connecting the lead-acid battery with the second storage battery, at least one electrical load electrically connected to the electrical path and disposed closer to the lead-acid battery, and a switch controller controlling the switch device to maintain a closed state except an engine start duration while the engine is being started by a starting device after a power of the vehicle is turned on.

Electric power source system

A battery system controller is provided which is used for a battery system including a generator, electrical loads, a lead storage battery, a high performance storage battery which has higher-power and higher-energy density, and an opening and closing switch which switches the generator and the lead storage battery, and the high performance storage battery to an electrically conducting state or an interrupted state, a terminal voltage of the high performance storage battery being controlled so as to be lower than a terminal voltage of the lead storage battery. The battery system controller includes a control unit which allows the opening and closing switch to switch from an electrically conducting state to an interrupted state on the condition that charging current flowing to the high performance storage battery is smaller than a determination value, the larger an internal resistance of the lead storage battery, the smaller the determination value is set.

Battery system controller

A power source apparatus mounted to a vehicle is equipped with a lead-acid battery and a lithium battery. An open circuit voltage and an internal resistance of each of the batteries are determined to satisfy the following conditions (a), (a), and (a): (a) In the use range of SOC of the lead-acid battery and the use range of SOC of the lithium battery, there is an equal voltage point Vds at which the open circuit voltage V(Pb) of the lead-acid battery becomes equal to the open circuit voltage V(Li) of the lithium battery; (a) The relationship of V(Li)&#x3e;V(Pb) is satisfied in the upper limit side of the use range of SOC of the battery; and (a) A terminal voltage Vc (Li) of the lithium battery is not more than a set voltage Vreg of a regulator when a maximum current flows in the lithium battery.

Power source apparatus for vehicle

The power supply unit includes a lead secondary battery (first battery) that is capable of being charged with power generated by an alternator (power generator); a lithium secondary battery (second battery) that is electrically connected in parallel to the lead secondary battery, capable of being charged with power generated by the alternator (power generator), and has higher output density or higher energy density than the lead secondary battery; and a switching means that is electrically connected between the alternator and the lead secondary battery, and the lithium secondary battery, and switches between conduction and blocking. The switching means is configured by a plurality of MOS-FETs (semiconductor switches) being connected in series such that respective parasitic diodes present in the semiconductor switches face opposite directions.

Power supply unit having plurality of secondary batteries

A power supply system mounted in a vehicle. A rotary machine is connected to an output shaft of an internal-combustion engine of the vehicle, and has a power generation function, an engine start-up function, and an engine output assist function. A first secondary battery and a second secondary battery are each electrically connected in parallel with the rotary machine. A connection switch is provided along a connecting line electrically connecting the first and second secondary batteries, where the connection switch is configured to electrically connect and disconnect the second secondary battery and a parallel connection of the first secondary battery and the rotary machine. A switch controller is configured to disconnect the second secondary battery and the parallel connection by controlling the connection switch to a current cut-off state during the engine start-up and during engine output assist.

Vehicle-mounted power supply system

A battery condition estimation device estimates a pre-restart voltage drop amount &#x394;Vjh+&#x394;Vbn of a battery mounted to a vehicle during period Tto Tfrom initiation of an engine stop until initiation of an engine restart based on detection values regarding the battery condition. The device estimates a voltage drop amount &#x394;Vst during period Tfrom initiation of the engine restart until completion of the engine restart based on the detection values regarding the battery condition. The device finally estimates a minimum voltage of the battery during period Tto Tfrom the initiation of the engine stop until the completion of the engine restart based on a voltage detection value Vjbefore the engine stop, the pre-restart voltage drop amount &#x394;Vjh+&#x394;Vbn, and the voltage drop amount &#x394;Vst.

Growing community of inventors

Nukata-gun, Japan

Shigenori Saito