A power module for providing rotational energy to a surgical handpiece, so that the handpiece can apply the energy to an energy applicator or a medical implant, said power module comprising: a shell (182, 204), said shell (182, 204) shaped to have: a base with a bottom plate, the base subtending a cross sectional area; a tower that extends from the base, the tower subtending a cross sectional area less than that of said base; a motor disposed in said shell tower, said motor having an output shaft that is accessible through an opening in said shell tower; at least one cell disposed in said shell base, said cell capable of storing charge for energizing said motor; characterized by a first set of sensors (286, 288) disposed in said shell base adjacent said bottom plate configured to detect the presence of magnetic fields generated external to said shell (182, 204) by a data tag of the surgical handpiece, said first set (286, 288) of sensors configured to generate first sensor signals based on the sensed magnetic fields; a second set of sensors (302, 304) disposed in said shell tower configured to detect the presence of magnetic fields generated external to said shell (182, 204), said second set of sensors (302, 304) configured to generate second sensor signals based on the sensed magnetic fields, wherein said first set of sensors (286, 288) and said second set of sensors (302, 304) are spaced at least 5 cm apart from each other; and a controller disposed in said shell (182, 204) that is configured to selectively connect said at least one cell to said motor for actuating said motor, said controller further configured to: receive the first sensor signals; receive the second sensor signals; and based on the received sensor signals regulate the application of current from said at least one cell to said motor so as to control the actuation of said motor. a shell (182, 204), said shell (182, 204) shaped to have: a base with a bottom plate, the base subtending a cross sectional area; a tower that extends from the base, the tower subtending a cross sectional area less than that of said base; a motor disposed in said shell tower, said motor having an output shaft that is accessible through an opening in said shell tower; at least one cell disposed in said shell base, said cell capable of storing charge for energizing said motor; characterized by a first set of sensors (286, 288) disposed in said shell base adjacent said bottom plate configured to detect the presence of magnetic fields generated external to said shell (182, 204) by a data tag of the surgical handpiece, said first set (286, 288) of sensors configured to generate first sensor signals based on the sensed magnetic fields; a second set of sensors (302, 304) disposed in said shell tower configured to detect the presence of magnetic fields generated external to said shell (182, 204), said second set of sensors (302, 304) configured to generate second sensor signals based on the sensed magnetic fields, wherein said first set of sensors (286, 288) and said second set of sensors (302, 304) are spaced at least 5 cm apart from each other; and a controller disposed in said shell (182, 204) that is configured to selectively connect said at least one cell to said motor for actuating said motor, said controller further configured to: receive the first sensor signals; receive the second sensor signals; and based on the received sensor signals regulate the application of current from said at least one cell to said motor so as to control the actuation of said motor.