Electric Motor: Serves two purposes in hybrid technology, namely as a motor and a generator. For example, when it serves as a motor, used to accelerate the vehicle and when it serves as a generator, used to slow down the vehicle and return energy to the vehicle. SOC: SOC stands for Battery State of Charge and it expresses availability in terms of Percentage of the nominal capacity of the battery.6. Design Parameter: The main objective of the hybrid electric vehicle is to convert the chemical energy of the batteries into mechanical energy which is used to drive the vehicle in the most efficient and environmentally friendly way. The main design parameter behind the system is batteries, electrical equipment. motors/generator, and necessarily a second source of torque with its fuel source. The second source of torque is often considered to be an internal combustion engine, running on gasoline. In other cases it may be an ICE powered by hydrogen, a diesel engine. The hybrid electric vehicle combines the two modes i.e. electric mode and ICE mode so that the system provides the maximum efficiency which is useful for the vehicle to go that far and most of the time. people prefer this type of vehicle with higher efficiency and emitting lower emission rate. In this project, electric battery mode is used at low speed and when higher speed requires, the vehicle will switch to internal combustion mode. By doing this, the efficiency of the vehicle is maintained at a constant rate.7. The hybrid vehicle drive system and adaptation of the layout to the vehicle: Hybrid electric drive systems are very complex and their design varies considerably from one vehicle to another. Batteries are usually balanced - either centered or split between the front and rear of the vehicle, and adjusted to the middle of the paper...... or will be started by a switch using Batteries (4 numbers) . This helps in moving the vehicle. MCB (miniature circuit breaker) is also provided in order to cut off the power supply at the instant. With the help of the controller, the limited amount of electric current is added or drawn from the electric batteries in to prevent overcharging and surges, which may reduce battery performance or life and pose a safety risk. It can also prevent completely draining ("deep discharging") a battery, or performing controlled discharges, depending on the battery technology, to protect battery life. The engine starts with the power switch ignition, because the engine delivers power to the connected pinion. at both ends of the motor shaft, using a chain drive, this allows the two side tires to move the vehicle.