The present invention discloses a portable labor-saving battery device for
a electric vehicle, said battery device capable of providing power when
installed on said electric vehicle. User is able to disassemble said
battery device, drag and recharge said battery independently without much
effort. Furthermore, said battery device is used as shopping cart to
provide more functionality. Said battery device mainly comprises a battery
set having a socket for recharge and a contact on a bottom of said battery
set for connecting to said electric vehicle, a cap implemented on a bottom
of a upper surface of said battery set, said cap lying next to said upper
surface of said battery set when folded up and providing a load-bearing
space when bent down. A wheel set is implemented on a bottom of a lower
surface of said battery set for providing mobility. Said battery set
having an extension bar penetrating through both sides of a top of said
battery set and extending into said battery, wherein said extension bar is
extensible inside said battery set for user to drag said battery device
easily other than hand carry said battery set.
