An apparatus for magnetically attaching to a load, comprising: a direct current power source; an electromagnet comprising a coil connectable to the direct current power source for feeding current to the coil for attaching to the load by a magnetic force; a current measurement device connected to the coil; characterized in that the apparatus comprises: a user interface for displaying information indicating a load capacity of the apparatus; and a controller operatively connected to the direct current power source, the coil, the current measurement device and the user interface to cause: connecting the direct current power source to the coil; measuring current of the coil; determining a rise time of the current to a nominal value of current of the coil, when the load is attached to the apparatus; determining a load capacity of the apparatus based on the rise time of the current to the nominal value, wherein the rise time is indicative of a level of magnetization of the load; and displaying the load capacity and/or a usage level of the load capacity on the user interface. a direct current power source; an electromagnet comprising a coil connectable to the direct current power source for feeding current to the coil for attaching to the load by a magnetic force; a current measurement device connected to the coil; characterized in that the apparatus comprises: a user interface for displaying information indicating a load capacity of the apparatus; and a controller operatively connected to the direct current power source, the coil, the current measurement device and the user interface to cause: connecting the direct current power source to the coil; measuring current of the coil; determining a rise time of the current to a nominal value of current of the coil, when the load is attached to the apparatus; determining a load capacity of the apparatus based on the rise time of the current to the nominal value, wherein the rise time is indicative of a level of magnetization of the load; and displaying the load capacity and/or a usage level of the load capacity on the user interface. a user interface for displaying information indicating a load capacity of the apparatus; and a controller operatively connected to the direct current power source, the coil, the current measurement device and the user interface to cause: connecting the direct current power source to the coil; measuring current of the coil; determining a rise time of the current to a nominal value of current of the coil, when the load is attached to the apparatus; determining a load capacity of the apparatus based on the rise time of the current to the nominal value, wherein the rise time is indicative of a level of magnetization of the load; and displaying the load capacity and/or a usage level of the load capacity on the user interface. connecting the direct current power source to the coil; measuring current of the coil; determining a rise time of the current to a nominal value of current of the coil, when the load is attached to the apparatus; determining a load capacity of the apparatus based on the rise time of the current to the nominal value, wherein the rise time is indicative of a level of magnetization of the load; and displaying the load capacity and/or a usage level of the load capacity on the user interface.