A vehicle determines a first resistance of a starter motor and a starter cable connected thereto based at least in part on the first voltage of a power source. The vehicle determines a predicted minimum battery voltage based at least in part on the first resistance of the starter motor and the starter cable. The vehicle, in response to the predicted minimum battery voltage satisfying a threshold, enables a vehicle stop-start function, and, in response to the predicted minimum battery voltage failing to satisfy the threshold, disables the vehicle stop-start function.

A booster is mounted on a vehicle having an idle stop function. The booster boosts an input voltage supplied from a battery, and outputs the boosted input voltage to an in-vehicle device. The booster includes a booster circuit and an output voltage sensor. The booster circuit is a chopper-type, and includes a reactor having one end connected to the battery and a switching element connected between an other end of the reactor and a ground. The output voltage sensor detects an output voltage of the booster circuit.

Devices and systems for determining an alternator condition in a motor vehicle are provided. The method includes performing a plurality of micro wakeups to capture voltage values during a cranking event, determining the maximum cranking voltage and its timestamp, detecting an ignition signal, determining the maximum device voltage and its timestamp, and determining a potential alternator undercharging condition if a duration between the maximum cranking voltage timestamp and the maximum device voltage timestamp is greater than an undercharging indicator duration threshold. Advantageously, an alternator may be repaired or replaced before it fails thus averting having the motor vehicles inoperable.

Disclosed is a system for detecting an operating state of a vehicle engine. The system comprises: an input coupled to a power line of a vehicle; means to filter out relatively high frequency transient noise components of a signal received from the power line; a first detector for receiving the filtered signal and detecting when transient noise associated with the power line rises above a first threshold and generating a first detection signal in response thereto; a second detector for receiving the filtered signal and detecting when the transient noise falls below a second threshold, which is lower than the first threshold, and generating a second detection signal in response thereto; and means for generating a first output signal in response to the first detection signal and a second output signal in response to the second detection signal.

An engine-driven generator may comprise an engine, a generator, a motor, a battery, a power supply circuit, and a processor. The processor may be configured to detect that the battery has a sufficient power supply capability that enables a piston of the engine to pass over a compression top dead center, at the start of the engine. The processor may permit ignition of the engine in a case where the processor has detected that the battery has the sufficient power supply capability. The processor may avoid the ignition of the engine in a case where the processor has not detected that the battery has the sufficient power supply capability.

A battery booster for jumpstarting a vehicle having an external battery. The battery booster may include a processor, a set of terminal connectors, a power supply, and a power-management circuit. The set of terminal connectors may be configured to couple with the external battery or an engine that is electrically coupled with the external battery. The power supply may include a lithium battery configured to supply a starting current to jump start an engine. The external battery may have a first nominal voltage, while the lithium battery may have a second nominal voltage that is greater than the first nominal voltage. The power-management circuit operatively coupled with the at least one processor, wherein the at least one processor is configured to transfer power selectively between the external battery and the power supply. The processor is configured to perform a pre-charge function and/or a back-feed function via the power-management circuit, which may employ a pulse width modulation (PWM) driver.

The vehicle power supply system includes the DC/DC converter that is disposed on an electric path between the first load related to vehicle control and the battery and converts a voltage of direct current power supplied from the battery to the first load, and the detection device that detects the voltage of the battery. In a case where the engine is restarted by using the starter from the automatically stopped state of the engine, the detection device controls the DC/DC converter to start in a case where the voltage of the battery becomes equal to or less than a threshold value during a period from stoppage of the alternator to start of the starter.

This disclosure provides systems, methods and apparatus for a engine start system. In one aspect, the engine start system includes: a booster battery selectively connected in parallel with the primary batteries of the engine. The booster battery is disconnected when the battery voltage of the primary batteries is below a first target voltage. The booster battery is connected when the battery voltage of the primary batteries is at or above the second target voltage, or in response to an external input.

An engine glow plug disconnection detection method may include: increasing, by a controller, temperature of a plurality of glow plugs by performing a rapid temperature increase mode when an engine start signal of a vehicle is recognized by the controller; determining whether the glow plugs are disconnected and the number of disconnections using an engine start early-stage voltage of the vehicle and a voltage of the vehicle when the rapid temperature increase mode is performed, by the controller; recognizing, by the controller, cylinders of an engine with at least a disconnected glow plug upon determining that one or more glow plugs are disconnected: and storing, by the controller, a number of disconnected glow plugs and information related to corresponding cylinders.

An idle reduction system for use with an engine can include a main unit including a controller, and a relay controlled by the controller. The relay can be electrically connected between an ignition switch and an electrical power source for starting the engine. A method of reducing idling of an engine can include connecting an idle reduction system, thereby permitting the system to shut down the engine in response to one or more predetermined conditions, the idle reduction system starting the engine in response to at least one of : a) battery voltage being less than a predetermined level, and b) engine temperature being less than a predetermined level, and the idle reduction system controlling operation of at least one of: an auxiliary air conditioner and an auxiliary heater.