The electrical system that helps gasoline-electric hybrids deliver great gas mileage can also deliver a deadly shock to an emergency worker trying to help an accident victim from a mangled car.
Fire departments around the country have begun training firefighters to minimize their chances of injury when rescuing people from hybrids.
Honda and Toyota have created guides for emergency workers to familiarize them with each model. The guides show the locations of the batteries and the kill switches. Toyota has offered to bring a hybrid to fire stations or ambulance stations upon request to provide a tutorial of how the car works.
High-voltage lines in hybrid cars are painted bright orange and are not running through parts usually found during extrications. But firefighters still need to know the potential danger of touching them, fire rescue workers say.
There is still no standardization with hybrids: The on/off switch is not in the same place, not every hybrid has an on/off switch and hybrid batteries can deliver up to 500 volts, enough to deliver a nasty shock and, under the right circumstances, even electrocute a rescue worker.
Each model of hybrid may require different procedures for disarming the vehicle.
The Toyota Prius, for example, has a removable circuit breaker on the side of the high-voltage battery that can be removed by a rescue worker in order to turn the car off. Honda hybrids are equipped with a shutoff switch, a little like a light switch, located behind the back seats or in the trunk.
Hybrid cars rely on electric motors for the most fuel-intensive aspects of acceleration, such as starting from a standstill. The vehicles revert to gasoline-fueled power when cruising. During cruising and braking, the gasoline engine charges the batteries to the electric motor, which saves on fuel consumption. In some models, energy created by braking is also used to charge the batteries.
Besides a 12-volt battery for the electrical system like those found in other cars, hybrid cars have a separate high-capacity battery pack to power the electric motor.
