* '''Electric motor''': Advanced electronics allow it to act as a motor as well as a generator. For example, when it needs to, it can draw energy from the batteries to accelerate the car. But acting as a generator, it can slow the car down and return energy to the batteries.
* '''SOC''': The State of Charge of a battery is its available capacity expressed as a percentage of its rated capacity.
[[Image:Image:Hev layout.jpg]]
== HEV battery system design parameters ==