Ni-MH Battery Charger with a Compensator for Electric Vehicles

The development of a high-performance battery and safe and reliable charging methods are two important factors for commercialization of the Electric Vehicles(EV) Hyundai and Ovonic together spent many years in the research on optimum charging method for Ni-MH battery This paper presents in detail the results of intensive experimental analysis, performed by Hyundai in collaboration with Ovonic

An on-board Ni-MH battery charger and its controller which are designed to use as a standard home electricity supply are described In addition, a 3 step constant current recharger with the temperature and the battery aging compensator is proposed This has a multi-loop algorithm function to detect its 80% and fully charged state, and carry out equalization charging control The algorithm is focused on safety, reliability, efficiency, charging speed and thermal management (maintaining uniform temperatures within a battery pack) It is also designed to minimize the necessity for user input.