Mild Hybrid EV (MHEV)
Instead of replacing the 12 volt unit the 48 volt system works with the standard battery. It’s connected to a hybrid motor and an electric supercharger, and takes over duties from the 12 volt unit such as powering the air-conditioning, catalytic converter and engine fan and provides a small boost to the drive (for starting off and assisting under acceleration). The battery is charged by regenerative means and switching off the engine when decelerating and at standstill. The battery does not have enough power to drive the car itself so there’s no electric motor so should it be called a Hybrid at all as drive is not coming from two sources? To put things into context, an electric car typically has a 40kWh battery, PHEV 10kWh, HEV 1.6kWh and a 48v mild hybrid battery equates 0.44kWh. The advantages to the driver are slightly decreased emissions, slightly increased performance and as drive is not coming from two sources, the ability to pair this system to a manual gearbox. The advantage to the Manufacturer is they can put ‘Hybrid’ all over the car for a very small outlay. This is the basket a lot of manufacturers are putting their eggs in; 50 percent of all hybrids sold by 2025 are projected to be a mild hybrid.
Hybrid Electric Vehicle (HEV)
A HEV uses the combined efforts of an ICE (internal combustion engine) and a battery-powered electric motor to drive the vehicle. The work of driving the vehicle is shared between the two propulsion sources in the best way possible at any given time. For instance, the electric motor can give the vehicle a boost of power, perhaps while merging or climbing a hill, without burning additional fuel. The vehicle may also be able to drive for brief periods solely on electrical power, particularly at pulling away, when later joined by the engine. Power for the electric motor is created by a built-in generator and stored in an on-board battery. In a HEV all power is generated on board and does not require plugging-in.