Truck Equipment Glossary - E
Electric Drive Vehicle
In an electric drive vehicle, torque is supplied to the wheels by an electric motor that is powered solely by a battery; an internal combustion engine using hydrogen, gasoline or diesel; or by a fuel cell.
Elevating Gate
A form of endgate used in conjunction with a hydraulic or mechanical hoisting mechanism to allow the gate to descend to ground level. Power elevation allows a gate to be used to raise freight to truck floor level for loading. Also referred to as a Lift Gate, Load Gate, Power Gate or Tailgate Lift.
Energy Storage Media (Electric)
Electrochemical devices utilized to store and release electric energy used for operating electric drive vehicles. Types of electric energy storage media include:
- Battery — A combination of one or more electrochemical cells used to convert stored chemical energy into electrical energy. Batteries are normally described by their mode of operation (primary cell, which is non-rechargeable, or secondary cell, which is rechargeable); their construction (wet or dry cell); and their construction materials.
- Lead Acid — A form of rechargeable battery (secondary wet cell) that uses lead and lead dioxide for the electrodes (charged state) and a dilute solution of sulfuric acid as an electrolyte. Lead acid batteries have a low energy-to-weight ratio but are low-cost and have the ability to supply high surge currents without being damaged.
- Lithium Ion (Li-ion Battery) — A type of rechargeable dry cell battery (secondary cell) in which the cathode (positive electrode) contains lithium. The anode (negative electrode) is generally made of a type of porous carbon. The non-aqueous electrolytes used in lithium ion batteries are typically based on patented formulations containing manganese or cobalt salts. Lithium ion batteries have a high energy density; are lighter than other energy-equivalent secondary batteries; and have a low self-discharge rate.
- Nickel-Metal Hydride (NiMH) — Nickel-metal hydride batteries (secondary cells) are related to sealed nickel-cadmium batteries. The only difference is that instead of cadmium, hydrogen is used as the active element at a hydrogen-absorbing negative electrode (anode). This electrode is made from a metal hydride (usually alloys of lanthanum and rare earths) that serves as a solid source of reduced hydrogen that can be oxidized to form protons. The electrolyte is alkaline potassium hydroxide. The energy density of NiMH batteries is more than double that of lead acid.
- Ultracapacitors (UltraCaps) — High-capacity electrochemical double-layer capacitors consisting of two electrodes immersed into an electrolyte. The electrodes are typically made of activated carbon which has a high, specific surface area of about 2,000 m2/g. UltraCaps have an unusually high energy density when compared to common capacitors, typically thousands of times greater than a high-capacity electrolytic capacitor.
Environmental Protection Agency (EPA)
A U.S. government agency established in 1970 to consolidate a variety of federal research, monitoring, standard-setting and enforcement activities to ensure environmental protection. The EPA’s mission is to protect human health and to safeguard the natural environment. Visit
www.epa.gov to learn more.
- SmartWaySM Transport — A collaboration between the EPA and the freight sector designed to improve energy efficiency, reduce greenhouse gas and air pollutant emissions, and improve energy security. Visit www.epa.gov/smartway/transport to learn more.
E-PTO (Electric Power Take-off)
An electric auxiliary drive used to power vehicle-mounted equipment instead of using power from the vehicle’s primary engine.
