With mass production, hybrid and electric vehicles have become more popular and affordable, especially as fuel costs and environmental concerns have risen. Some common innovative technologies have made increased efficiency possible.
Start-Stop Technology. Start-stop technology, also known as an idle-stop system, automatically shuts down the engine at stops (when not under a load) and restarts upon acceleration. Reducing engine idle time saves up to 15 percent in fuel overall. A vehicle with the engine running, while sitting still, is the most inefficient way to burn fuel. Start-stop technology originated with hybrids, but is now also available on some conventional vehicles utilizing a specially adapted starter and programming. Start-stop technology is a very cost effective way to increase fuel economy and reduce emissions.
Regenerative Braking. Regenerative braking occurs when the electric motor acts as a generator to slow the vehicle and capture kinetic energy that would normally be lost as friction heat. This kinetic energy is converted to electrical energy to recharge the high voltage battery pack. Regenerative brakes do not replace conventional hydraulic brakes that are needed for more rapid stopping, but they do improve braking efficiency and reduce wear on conventional brake pads. To maximize regenerative braking, apply even pressure gradually when braking so the conventional brakes will not need to engage. Braking hard or braking and releasing repeatedly will not allow efficient regenerative braking.
High Voltage Battery Pack. Hybrid and electric vehicles have a standard 12V DC battery and a separate high voltage battery pack for storing energy. The battery pack is usually located where it is more protected against accidents (under the back seat, behind the back seat, in the trunk, or down the center console). High voltage batteries, commonly nickel metal hydride (NiMH) or lithium-ion, can hold a great deal more energy than a standard lead acid battery. High voltage battery cables can be identified by their bright orange color. Warning: To avoid injury, shock, burn, or death the high voltage battery pack is equipped with a service disconnect. Always follow manufacturer recommended precautions in the service manual and on warning labels when servicing a hybrid or electric vehicle.