A hybrid vehicle using an engine driving a generator to supply power to electric drive motors through a system power bus, and a method for controlling power regeneration in a hybrid vehicle are disclosed. Ground drive controllers associated with the drive motors are configured to determine a slope of a surface on which the vehicle is driving and set a maximum downhill speed of the vehicle based thereon. A generator controller, in response to the drive motors generating power through regenerative braking, regulates power on the bus by directing the generated power to recharge the battery when the battery has capacity, reducing an output of the generator to the bus when the battery is fully charged, and driving a driveshaft to drive the engine with the generator to consume excess power on the bus when the generator output is reduced to zero.

A fire fighting vehicle includes a front axle, a rear axle, an engine, an energy storage device, an electromechanical transmission, a fluid tank configured to store a fluid, a pump configured to provide the fluid from the fluid tank to a fluid outlet, and a power divider positioned between the engine, the pump, and the electromechanical transmission. The power divider includes a first interface coupled to the engine, a second interface coupled to the pump, and a third interface coupled to the electromechanical transmission. The electromechanical transmission is (i) selectively mechanically coupled to the engine by the power divider and (ii) electrically coupled to the energy storage device to facilitate driving at least one of the front axle or the rear axle. The pump is selectively mechanically coupled to the engine by the power divider to facilitate pumping the fluid to the fluid outlet.

A fire fighting vehicle includes a chassis, tractive elements coupled to the chassis, a pump coupled to the chassis, a discharge fluidly coupled to the pump, an accessory module coupled to the chassis, and an electric motor coupled to the chassis, the pump, and the accessory module. The accessory module is configured to receive mechanical energy and provide at least one of electrical energy or fluid energy. The electric motor is configured to drive (a) the pump to provide fluid to the discharge such that the fluid is expelled from the discharge and (b) the accessory module to provide the at least one of electrical energy or fluid energy.

A fire fighting vehicle includes a powertrain including an engine, a battery pack, and an electromechanical transmission; a power divider; and a controller. The power divider is positioned between the engine, the pump, and the electromechanical transmission. The controller is configured to monitor a state-of-charge of the battery pack and operate the engine, the power divider, and the electromechanical transmission such that the state-of-charge is maintained above a minimum state-of-charge threshold that is sufficient to facilitate (i) accelerating the fire fighting vehicle to a driving speed of at least 50 miles-per-hour in an acceleration time and (ii) maintaining or exceeding the driving speed for a period of time. An aggregate of the acceleration time and the period of time is at least three minutes.

A fire fighting vehicle includes a powertrain, an accessory drive, and a controller. The powertrain includes an engine, an energy storage device, and an electromechanical transmission (i) electrically coupled to the energy storage device and (ii) selectively mechanically coupled to the engine. The electromechanical transmission is configured to (a) selectively drive a front axle and/or a rear axle and (b) selectively generate energy for storage in the energy storage device as stored energy. The accessory drive is positioned to receive a mechanical input from the engine and the electromechanical transmission. The controller is configured to selectively operate the powertrain in (i) a standby mode by operating the electromechanical transmission using the stored energy to drive the accessory drive with the engine off and (ii) a rollout mode by operating the electromechanical transmission using the stored energy to drive the front axle and/or the rear axle with the engine off.

A fire fighting vehicle includes a front axle, a rear axle, an engine, an energy storage device, an electromechanical transmission, a fluid tank configured to store a fluid, a pump configured to provide the fluid from the fluid tank to a fluid outlet, and a power divider positioned between the engine, the pump, and the electromechanical transmission. The power divider includes a first interface coupled to the engine, a second interface coupled to the pump, and a third interface coupled to the electromechanical transmission. The electromechanical transmission is (i) selectively mechanically coupled to the engine by the power divider and (ii) electrically coupled to the energy storage device to facilitate driving at least one of the front axle or the rear axle. The pump is selectively mechanically coupled to the engine by the power divider to facilitate pumping the fluid to the fluid outlet.

A fire fighting vehicle includes a powertrain, an accessory drive, and a controller. The powertrain includes an engine, an energy storage device, and an electromechanical transmission (i) electrically coupled to the energy storage device and (ii) selectively mechanically coupled to the engine. The electromechanical transmission is configured to (a) selectively drive a front axle and/or a rear axle and (b) selectively generate energy for storage in the energy storage device as stored energy. The accessory drive is positioned to receive a mechanical input from the engine and the electromechanical transmission. The controller is configured to selectively operate the powertrain in (i) a standby mode by operating the electromechanical transmission using the stored energy to drive the accessory drive with the engine off and (ii) a rollout mode by operating the electromechanical transmission using the stored energy to drive the front axle and/or the rear axle with the engine off.

An electrified fire fighting vehicle includes a chassis, a cab coupled to the chassis, a body coupled to the chassis, a front axle coupled to the chassis, a rear axle coupled to the chassis, a water tank supported by the chassis, an energy storage system coupled to the chassis, a water pump supported by the chassis, and an electromagnetic device electrically coupled to the energy storage system. The electromagnetic device is coupled to the water pump and at least one of the front axle or the rear axle. The electromagnetic device is configured to receive stored energy from the energy storage system and provide a mechanical output to selectively drive the water pump and the at least one of the front axle or the rear axle.

A fire fighting vehicle includes a chassis, a front axle, a rear axle, a powertrain, an accessory drive, and a controller. The powertrain includes an engine, a battery system, and an electromechanical transmission coupled to the battery system, the engine, and at least one of the front axle or the rear axle. The accessory drive is positioned to receive a mechanical input from the engine and the electromechanical transmission. The controller is configured to selectively operate the powertrain in a plurality of operational modes including a standby mode and a hybrid mode. According to the standby mode, the controller is configured to operate the electromechanical transmission using stored energy stored in the battery system to drive the accessory drive with the engine off. According to the hybrid mode, the controller is configured to operate both the engine and the electromechanical transmission.

An electrified fire fighting vehicle includes a battery pack, an electromagnetic device, an engine, and a controller. The controller is configured to monitor a state-of-charge of the battery pack, operate the electromagnetic device using stored energy in the battery pack to provide a performance condition including (i) accelerating the electrified fire fighting vehicle to a driving speed of at least 50 miles-per-hour in an acceleration time and (ii) maintaining or exceeding the driving speed for a period of time, and start and operate the engine in response to a start condition to facilitate reserving sufficient stored energy in the battery pack such that the state-of-charge is maintained above a minimum state-of-charge threshold that is sufficient to facilitate the performance condition. The acceleration time is 30 second or less. An aggregate of the acceleration time and the period of time is at least 3 minutes.