Referring to FIGS. 10 and 11, the end shell 400 is provided with an end cap charging head 403 for charging the lithium battery pack 3, and the end shell 400 is provided with an end cap mounting slot 408 for inserting and limiting the end cap charging head 403. Furthermore, an end cap mounting plate 404 is mounted on one side of the end shell 400 close to the end cap charging head 403, and the end cap mounting plate 404 is used for pressing and fixing the end cap charging head 403.

The end cap charging head 403 is integrally provided with an end cap positioning post 405 on one side close to the end cap mounting plate 404, and the end cap mounting plate 404 is provided with an end cap through hole 409 through which the end cap positioning post 405 penetrates, and finally is fixed by bolts.

One side of the end shell 400 close to the base shell 100 is fixed with an end cap mounting box 406 by bolts, and an end cap plug 407 connected to the connecting circuit board 204 is mounted in the end cap mounting box 406, so as to provide energy, and an end cap receptacle 410 for inserting the end cap plug 407 is provided on the end shell 400.