Method for estimating the state of charge of an electric battery of an electrified vehicle implemented in an electric charging system for electrified vehicles comprising electric charging means connected to an electrical supply network and ensuring an electric recharge of said electric battery, at least a first computer server (NS1, SRC) hosting a software system for managing connected vehicles and a wide area data communication network through which said electrified vehicle and said first computer server (NS1, SRC) are in data communication, and where said method comprises, at the start of an electric charging session at a time t o, a first communication of data from said electrified vehicle to said first computer server (NS1, SRC), said first communication of data comprising electric charging session data including vehicle identification data (VE/USER), a first effective state of charge (S0 C 0), of said electric battery, a state of health of said electric battery and a charging mode; and characterized in that: during said electric charging session, an estimate and a provision by said first computer server (NS1, SRC) of a load status estimated (SOC E), said estimated state of charge (SOC E) being determined from said electric charging session data, an energy capacity (C, E) of said electric battery and a first estimation calculation factor ( α s), said first estimation calculation factor ( α s) being determined by selection from a database of estimation calculation factors (DB α) accessible to said first computer server (NS1, SRC) and from said electric charging session data. (NS1, SRC) are in data communication, and where said method comprises, at the start of an electric charging session at a time t o, a first communication of data from said electrified vehicle to said first computer server (NS1, SRC), said first communication of data comprising electric charging session data including vehicle identification data (VE/USER), a first effective state of charge (S0 C 0), of said electric battery, a state of health of said electric battery and a charging mode; and characterized in that: during said electric charging session, an estimate and a provision by said first computer server (NS1, SRC) of a load status estimated (SOC E), said estimated state of charge (SOC E) being determined from said electric charging session data, an energy capacity (C, E) of said electric battery and a first estimation calculation factor ( α s), said first estimation calculation factor ( α s) being determined by selection from a database of estimation calculation factors (DB α) accessible to said first computer server (NS1, SRC) and from said electric charging session data. during said electric charging session, an estimate and a provision by said first computer server (NS1, SRC) of a load status estimated (SOC E), said estimated state of charge (SOC E) being determined from said electric charging session data, an energy capacity (C, E) of said electric battery and a first estimation calculation factor ( α s), said first estimation calculation factor ( α s) being determined by selection from a database of estimation calculation factors (DB α) accessible to said first computer server (NS1, SRC) and from said electric charging session data.