This paper deals with the modeling of the brushed DC motor used as a reinforced starter for a micro-hybrid automotive application. The aim of such a system, also called \stop-start", is to stop a combustion engine when the vehicle pulls to a stop, and to restart it when the driver accelerates. A reinforced starter is able to ensure this new function in addition to the classical cold start. Then, its life time has to be widely increased in comparison with a classical starter. They have to be optimized, and more especially their process of commutation in order to minimize commutator and brush wears, and thereby increase the lifetime of the device up to the whole life of the vehicle. The main contribution of the paper is the development of a coupled FE-circuit model taking into account local saturation and arc phenomena. Brush-segment contact resistance introduced in the circuit model has been computed efficiently and compared to measures. The whole model has been validated by experimental measurements which are carried out with specific experimental test benches.