EV Glossary – Electric Vehicle Dictionary

AC Charging (Alternating Current Charging) is the standard method of charging an EV from standard residential or commercial AC electrical grids. An On-Board Charger (OBC) inside the vehicle converts AC into DC to charge the traction battery.

Ampere-Hour (Ah) is a unit of electric charge measuring battery capacity, indicating how many amperes of current a battery cell or pack can supply continuously for one hour before depletion.

ARAI Range is the official certified driving range of an electric vehicle in India, tested under laboratory Indian Driving Cycle (IDC) conditions by the Automotive Research Association of India.

Battery Management System (BMS) is the vital electronic controller and brain of an EV battery pack that monitors cell voltages, temperatures, current draw, and State of Charge (SoC) to safeguard against fire and prolong battery life.

Battery Swapping is a refueling technology where an empty EV battery pack is physically removed and swapped with a fully charged unit at an automated or manual kiosk station in under two minutes.

BLDC Motor (Brushless Direct Current Motor) is an electric motor operating without mechanical carbon brushes, delivering higher energy efficiency, quieter operation, zero friction wear, and negligible maintenance.

C-Rate measures the speed at which a battery is charged or discharged relative to its maximum storage capacity. A 1C rate charges or discharges the complete pack in 1 hour; a 2C rate does so in 30 minutes.

CC-CV Charging (Constant Current - Constant Voltage) is the standard 2-phase charging algorithm for lithium-ion batteries. It applies constant high current up to ~80% capacity, then maintains constant voltage with tapering current to 100%.

CCS2 Connector (Combined Charging System Type 2) is India's and Europe's official mandatory fast-charging connector standard for four-wheeler electric vehicles, combining AC Type 2 pins with two heavy-duty DC pins.

Cell Balancing is a BMS process that equalizes voltage levels across hundreds of individual lithium cells in a battery pack to prevent overcharging strong cells or over-discharging weaker cells.

Combined Charging System (CCS) is an international open standard that unifies single-phase AC, three-phase AC, and high-voltage DC fast charging into a single inlet port on the vehicle body.

Continuous Power is the sustained motor power output an EV can maintain continuously without thermal throttling. Peak Power is the maximum burst power output available for brief accelerations.

Cycle Life is the total number of full 0% to 100% charge and discharge cycles a battery cell can undergo before its maximum usable storage capacity degrades below 70% to 80% of its original rating.

DC Fast Charging bypasses the vehicle's onboard AC converter, supplying direct high-voltage current straight from a commercial charging unit into the battery pack, replenishing 10% to 80% charge in 25 to 50 minutes.

DC-DC Converter is an electronic power unit that steps down the high traction voltage (e.g. 400V or 72V) to a standard 12V DC level to safely power auxiliary electronics like headlights, screens, horn, and ABS modules.

Depth of Discharge (DoD) indicates the percentage of total battery capacity that has been discharged relative to its maximum capacity. For instance, using 60 kWh from a 100 kWh pack equals 60% DoD.

Drive Modes are calibrated software settings that alter motor throttle response, torque output, top speed limits, and regenerative braking strength to optimize either maximum range or high-acceleration performance.

Energy Density is the amount of electrical energy stored per unit weight (Wh/kg - gravimetric) or volume (Wh/L - volumetric). Higher energy density allows longer driving range without adding excessive battery pack weight.

EV (Electric Vehicle) is any road transport vehicle propelled entirely or partially by one or more electric motors drawing electricity stored in a high-capacity rechargeable traction battery.

EVSE (Electric Vehicle Supply Equipment) is the dedicated hardware unit—including power cables, contactors, ground fault sensors, and digital handshake controllers—that safely delivers grid power to the EV.

FAME Subsidy (Faster Adoption and Manufacturing of Electric Vehicles) was the Government of India's flagship incentive scheme (FAME I & FAME II) offering direct price reductions on EV scooters, three-wheelers, and electric buses.

Fast Charging refers to any high-powered charging standard (typically 25 kW to 150+ kW DC for passenger cars, or 1.5 kW+ DC for two-wheelers) designed to replenish battery pack range in under an hour.

GaN Charger (Gallium Nitride Charger) uses advanced Gallium Nitride semiconductor material instead of silicon, achieving up to 3x faster switching, lower heat losses, and enabling ultra-compact, lightweight portable EV chargers.

GB/T Connector is the Chinese DC fast charging standard adopted in early Indian EV guidelines as Bharat DC-001 (15 kW 72V) for commercial fleet vehicles like early Tata Tigor EV and Mahindra e-Verito.

Gross Vehicle Weight (GVW) is the maximum legally permitted total operating weight of an electric vehicle when fully loaded with chassis, heavy battery pack, motor, driver, passengers, fluids, and luggage.

Hub Motor (In-Wheel Motor) is an electric motor mounted directly inside the wheel hub, driving the wheel directly without the need for transmission chains, drive belts, or gearboxes.

ICE (Internal Combustion Engine) is the conventional propulsion system burning petrol, diesel, or CNG to generate mechanical power, with lower thermal efficiency (~25-30%) and tailpipe exhaust emissions compared to 90%+ efficient EV motors.

Traction Inverter is the high-power electronic device that converts direct current (DC) supplied by the high-voltage battery pack into variable-frequency alternating current (AC) to spin the motor at desired speeds.

IP Rating (Ingress Protection) is an international standard rating indicating how hermetically sealed an EV's battery pack and motor casing are against dust ingress and water submersion.

Kilowatt (kW) is the standard unit of electric power (1 kW ≈ 1.341 horsepower). In EVs, kW is used to rate motor power output and charging station delivery speeds.

Kilowatt-Hour (kWh) is the standard unit of electrical energy storage in an EV battery pack, representing one kilowatt of electrical power maintained for one hour.

Level 1/2/3 Charging are international charging tiers: Level 1 is standard low-power AC (1.4–2.5 kW), Level 2 is high-power AC wallbox (3.3–22 kW), and Level 3 is commercial DC fast charging (50–350 kW).

LFP Battery (LiFePO4) is a cobalt-free lithium battery chemistry celebrated for exceptional thermal stability, resilience in extreme heat, long cycle life (2,000–3,000+ cycles), and affordability.

Liquid Cooling is an active thermal management system that circulates glycol-water coolant through aluminum cooling plates and channels between battery cells to maintain optimum temperatures (20°C–35°C).

Lithium-ion Battery is the primary family of rechargeable electrochemical energy storage systems powering modern electric mobility, moving lithium ions between cathode and anode during charge and discharge.

Mid-Drive Motor is an electric motor mounted centrally within the vehicle chassis frame, transferring torque to the rear wheel through a durable belt or chain drive.

NMC Battery (LiNiMnCoO2) is a high-energy-density lithium chemistry combining nickel, manganese, and cobalt to provide maximum driving range per kilogram of battery weight.

OBC (On-Board Charger) is the factory-installed AC-to-DC power converter module inside the electric vehicle that converts incoming AC power from wall boxes or sockets into high-voltage DC to recharge the battery.

OTA Updates are wireless software updates transmitted directly to an EV via embedded 4G/5G eSIM cellular networks, enabling manufacturers to enhance motor tuning, improve BMS algorithms, fix bugs, and add new features remotely.

PDU (Power Distribution Unit) is a protected high-voltage junction module that safely distributes electricity from the main traction battery pack to the motor inverter, DC-DC converter, and AC compressor with built-in fuses.

Peak Power is the absolute maximum electrical or mechanical power in kW (or bhp) that an electric motor can generate for short intervals during steep climbing or rapid overtaking.

PMSM (Permanent Magnet Synchronous Motor) is a high-efficiency electric motor utilizing permanent magnets in the rotor, delivering superior torque density, compact size, and over 95% operating efficiency.

PMDC Motor (Permanent Magnet DC Motor) is an older brushed DC motor utilizing stator magnets and a commutator. While simple and cheap, it has mechanical friction and wear from brushes.

PM E-DRIVE Scheme is the Indian central government's mega ₹10,900 crore initiative launched in 2024 to accelerate adoption of electric 2-wheelers, 3-wheelers, e-buses, and fund public fast-charging infrastructure.

Portable Charger is a mobile charging cable with a built-in safety control box bundled with electric vehicles that plugs into standard 15A/16A 3-pin household electrical sockets.

The three primary physical form factors of lithium-ion cells: Cylindrical (sturdy metal cans like 21700), Prismatic (rigid rectangular blocks with great space efficiency), and Pouch (flexible laminated polymer packets).

Range Anxiety is the psychological stress or worry experienced by an EV driver that vehicle battery charge will run out before reaching their destination or locating an available charging station.

Real-World Range is the actual distance an EV covers on a 100% full charge under everyday driving conditions (with real passenger loads, AC on, traffic stops, and high speeds) rather than idealized lab tests.

Regenerative Braking is an energy recovery system where the electric motor reverses function during coasting or braking, converting the vehicle's kinetic energy into electricity to recharge the battery while slowing the vehicle.

Smart BMS is an advanced battery management system integrated with Bluetooth, CAN-bus, and cloud telematics, allowing smartphone apps and remote diagnostics to track individual cell health and temperatures in real-time.

SoC (State of Charge) is the percentage of usable electrical energy remaining in the battery pack relative to its maximum capacity, ranging from 0% (empty) to 100% (fully charged), serving as the digital fuel gauge.

SoH (State of Health) is a critical diagnostic percentage comparing a used battery pack's current maximum energy storage capacity against its original brand-new factory capacity (100%).

Solid-State Battery is a next-generation battery technology replacing conventional liquid or polymer gel electrolytes with a solid ceramic or polymer electrolyte, eliminating flammability and doubling energy density.

Swappable Battery is a modular, lightweight removable battery pack designed with safety handles and smart connectors that allows scooter and rickshaw drivers to swap empty packs for full ones in seconds.

Single-Pedal Driving is an EV driving mode utilizing high regenerative braking torque that brings the vehicle to a complete stop simply by lifting off the accelerator pedal without pressing the brake.

Thermal Management System (TMS) is the integrated cooling and heating network (air, liquid, or refrigerant-based) that maintains battery cells, inverter, and electric motor within their optimal temperature zone (15°C to 35°C).

Thermal Runaway is an uncontrollable, self-sustaining exothermic chain reaction inside a damaged, overheated, or short-circuited battery cell where escalating internal temperature generates immense heat and flammable gases.

Top Speed is the maximum velocity in km/h an electric vehicle can achieve, often electronically governed to safeguard the electric motor from over-revving and prevent rapid battery drain.

Torque is the rotational pulling force generated by a motor measured in Newton-meters (Nm). Electric motors deliver 100% of maximum torque instantaneously from 0 RPM, providing immediate acceleration.

Type 2 Connector is the universal standard 7-pin AC charging connector used across India and Europe, supporting single-phase AC charging up to 7.4 kW and three-phase AC up to 22 kW.

Ultra-Fast Charging refers to high-power DC fast-charging systems delivering 120 kW to 350 kW+ using liquid-cooled cables, allowing high-voltage 800V EV architectures to add 200+ km range in under 15 minutes.

V2G (Vehicle to Grid) is a bidirectional charging technology enabling electric vehicles to feed stored electrical energy back into the public power grid during peak demand hours, earning revenue for EV owners.

V2H (Vehicle to Home) allows an EV to act as a massive home battery backup during power outages, supplying 230V AC electricity to run home lights, fans, refrigerators, and air conditioning for days.

V2L (Vehicle to Load) enables an EV to supply standard 230V AC household power via an adapter plug to power external appliances, laptops, induction stoves, power tools, or charge another broken-down EV.

Wall Box is a dedicated wall-mounted AC charging station installed in homes, garages, or apartment parking slots, delivering fast, safe, and metered charging (typically 3.3 kW, 7.4 kW, or 11 kW).

Watt-Hour (Wh) is the foundational metric unit of electrical energy storage representing one watt of power sustained for one hour (1,000 Watt-hours equals 1 Kilowatt-hour / kWh).

Zero Tailpipe Emissions refers to the environmental fact that pure battery electric vehicles (BEVs) emit zero carbon monoxide, NOx, particulate matter (PM2.5), or unburned hydrocarbons directly from the vehicle into city air.