HYBRID VEHICLES DRILL OF THE MONTH
WHAT IS A HYBRID VEHICLE? Any vehicle which combines two or more sources of power. Examples: • Diesel – electric • Nuclear – electric • Gasoline - electric
HYBRID STRUCTURE The two power sources found in hybrid vehicles may be combined in different ways, either in parallel or series Either one will allow the gasoline engine to shut down when it is not needed.
PARALLEL HYBRID • Gasoline motor • Batteries which powers an electric motor • Both can power the transmission at the same time • Electric motor supplements the gasoline engine
SERIES HYBRID • Gasoline motor turns a generator • Generator may either charge the batteries or power an electric motor that drives the transmission • At low speeds is powered only by the electric motor
HIGH VOLTAGE ELECTRICAL SYSTEMS • Power for the electric motor is supplied by high-voltage nickel-metal hydride battery • Batteries for all hybrids are produced by Panasonic EV Energy in Japan • Voltage ranges from 144 volts to 650 volts of DC current
HIGH VOLTAGE ELECTRICAL SYSTEMS • High voltage wiring may color coded orange, bright blue or even yellow • Batteries vary in design, however, all incorporate individual cells connected to one another
BATTERIES • Individual cells originally contained liquid potassium hydroxide • The liquid is almost totally absorbed by the paper membranes inside each cell of the battery • Because the liquid is absorbed these batteries are considered “dry cell” batteries
HIGH VOLTAGE ELECTRICAL SYSTEMS • Batteries are usually located in the rear of the vehicle under the floor of the trunk or under the rear seat. • The wiring harness from the batteries usually runs below the floorpan of the vehicle about one foot in from the driver’s side of the vehicle.
BATTERY RECHARGING • The Ni-MH batteries are recharged through a process call regenerative braking • Regenerative braking takes energy from the forward momentum of the vehicle and captures it while coasting or braking. • Occasionally batteries are recharged by the electric motor
THE “SILENT” HYBRID • Most gasoline engines in hybrids will shut off when not needed – i.e. when stopped in traffic • Most hybrids have an indicator light which may alert individuals to the status of the vehicle
THE “SILENT” HYBRID • When the vehicle is in this silent mode it may “awaken” without notice • Chocking the wheels is critical to responder safety
EMERGENCY PROCEDURESFIRES • Vehicle fires can be handled following normal vehicle firefighting procedures • Crews should not be shocked, even if flames are impinging on the battery pack itself • Virtually all fires involving Ni-MH batteries can be controlled with water
EMERGENCY PROCEDURESNi – MH BATTERY PACK PHYSICAL DAMAGE • High-voltage circuits are color-coded either orange, bright blue or yellow • Never disassemble or remove the metal cover of the high-voltage battery pack • DC current is normally isolated from any contact with the vehicle itself – theoretically in order to receive a shock you would have to physically contact two separate points within the high-voltage system at the same time
EMERGENCY PROCEDURESNi – MH BATTERY PACK PHYSICAL DAMAGE • If the high-voltage cables running under the vehicle were damaged the high-voltage battery is designed short circuit. • This short circuit would de-energize the entire high-voltage battery circuit
HYBRID VEHICLES – CRASH PROCEDURES • Hybrid vehicle identification • Vehicle stabilization • Access to the passenger compartment • Shift gear selector lever (to park) • Turn the key “OFF” and remove it from the ignition • Check that the “ready” indicator light is out • Disconnect the 12-volt battery.
HYBRID VEHICLES – OTHER CONSIDERATIONS • A rear-end collision would destroy the most obvious hybrid vehicle logos • Indicator light on the dash would help identify • Vented c-pillar on older hybrids • Orange wiring under the hood • If the high-voltage battery is severely damaged it should be considered a hazmat incident • This is not true, the total amount of liquid originally placed in the batteries is only around 6 oz.; this is almost totally absorbed by the paper membranes in the cells
KEYLESS IGNITION SYSTEMS • Convenience of push button start • Systems are designed to deter theft and break-ins • Utilize key fobs which contain a chip with an ID code that the vehicle must recognize • The key fob must be in the vehicle in order for the car to start
KEYLESS IGNITION SYSTEMSWhat do we do in an emergency? • Place the vehicle in Park and press the start/stop or power button. • If possible remove the key fob from the interior of the vehicle – this may be difficult since it may be in a purse or pants pocket. This will prevent the car from being powered up if the low voltage system cannot be secured. • Disconnect the low voltage battery per department policy.
Lexus RX 400h SUV GS 450h LS 600h L Mercury Mariner SUV Dodge Ram – contractor’s edition General Motors Silverado and Sierra Malibu Tahoe/Yukon Nissan Altima Versa WHO’S MAKING HYBRIDS NOW? • Honda • Accord • Civic • Insight • Toyota • Prius • Camry • Highlander • Ford • Escape • Mazda • Tribute • Saturn • Vue
WHAT’S IN STORE FOR THE FUTURE? • Toyota Sienna minivan • Chrysler Aspen • Cadillac Escalade • Dodge Durango • Porsche Cayenne • BMW X6 • Hyundai Accent • Mercedes Benz S400
SUMMARY Due to the proliferation of hybrid vehicles on the road today, responders must be familiar with how these vehicles operate, and how to handle an emergency which involves one of these vehicles. Additionally, responders must stay up-to-date with current vehicle technology, as it is continuously changing.