Developing fast-charging protocols for Li-ion batteries is a key issue for a wider deployment of electric vehicles and portable electrical devices. In this study, fast-charging of lithium iron phosphate batteries is investigated with different protocols. High charging rates are used with an extended constant current period thanks to a higher limit voltage based on the ohmic-drop compensation principle. This study shows that a compromise has to be found between the charging time and the durability of the battery. As an example a 6C charge with 57% ohmic-drop compensation allows to reach 95% of charge in 11min and the full charge in half an hour. With this protocol, more than 1500 cycles are reached before getting below 80% of state of health.