Novel glycolipid derivatives, where the substituent of the sphingosine base part is a short carbon chain alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted aryl group or substituted or unsubstituted aralkyl group and efficient synthetic methods for practical mass production of the same and intermediates useful for the synthesis of these compounds. The method includes measuring the current or voltage of a vehicle battery for a predetermined period of time, and then notch filtering the measured current or voltage signal to remove known harmonics. The wound structure of the stack has a side surface that is substantially parallel to the first side edge, and a top surface and a bottom surface, each of which is substantially perpendicular to the first side edge. A predetermined auxiliary current is outputted to the laser.