This paper presents a fully embedded State of Health estimator for widely used lithium iron phosphate batteries. The study was done including technical and cost constraints of automotive industry. An online estimator using Incremental Capacity Analysis and a Butterworth filter is studied. Cells were aged using pure electric vehicle cycles and were monitored with an automotive Battery Management System. Using this electronic platform and considering incomplete charge/discharge cycles, a 2% accurate State of Health estimator is proposed.