The battery management control components comprise the electronic control unit types BMU (battery management unit) and the CSSU (cell supervising sensor unit). These control units provide a uniform charge for the high-voltage battery for optimum battery performance. The high-voltage batteries are always in use, due to energy consumption in electric-only driving, as well as through the energy recovery during braking and while charging. Moreover, the battery cells have typically different charge levels depending on the degree of aging and manufacturing tolerances. For this reason, the CSSUs permanently monitor every single battery cell with regard to voltage and also temperature. These data will be processed in the battery management unit to offset the different charging states (balancing), and to ensure optimum battery performance.
In addition to the i3, other vehicles of the Munich manufacturer have Preh battery management know-how onboard. These include the purely electrically powered BMW ActiveE, as well as hybrid vehicles, including the ActiveHybrid 5 and also the BMW C evolution e-scooter.
Preh GmbH is a subsidiary of the exchange-listed Joyson Electronics, Ningbo, China (600699: Shanghai), and represents the Automotive Electronics Division of the Joyson Group. With headquarters in Bad Neustadt a. d. Saale, Germany, the company has production sites in Portugal, Romania, Mexico and China, as well as a development center in Novi/Detroit, Michigan, U.S.A and comprises about 3,500 employees worldwide. Preh’s development and manufacturing skills are concentrated on climate and driver control systems, electronic control units, sensors and assembly systems for leading automobile manufacturers.