A secure electrical connector set compatible with a conventional vehicle cigarette lighter includes: a female connector having an external thread for at an inlet outer diameter of the female connector; and a male connector having a flange and an internally threaded locking cap; wherein the male connector is configured to be inserted into the female connector such that: the flange of the plug contacts an inlet end of the female connector; the internal thread of the locking cap is screwed onto the external thread of the female connector; and the male and female connectors are securely coupled mechanically while achieving an electrical connection therebetween.