Abstract: A hand-held power tool having an elongated internal vertical housing 12 in a handle 11 with opposed vertical electrical housing contacts 13 carried adjacent respective opposed vertical side walls 12a and 12b of the housing is provided with an adaptor plug 14 and connector D for substituting an external automotive battery 21 for internal batteries for supplying power to the tool. An elongated adaptor body member A is carried for vertical disposition within the housing 12. A pair of opposed electrical adaptor contacts B adjacent one end of the body member A is resiliently biased laterally outwardly thereof into engagement with respective vertical electrical housing contacts 13. A conforming member C spaced longitudinally along the adaptor body member A from the adaptor contacts B aids in guiding and positioning the elongated adaptor body member A in the housing 12.