A battery comprising a shell, a locating seat, an end cover, a battery cell, a positive contact, a positive plate, a negative plate, a positive connecting plate and a negative connecting plate; wherein the shell is a cylinder having an upper opening and a contact extending hole on a center of a bottom plate of the shell; an upper end face of the locating seat is arranged with a mounting hole of the negative plate; the locating seat further includes a through hole for positive plate and a through hole for negative plate while the through hole for negative plate communicates with the mounting hole; the end cover is mounted with a central hole and an upper end face thereof is arranged with a positive plate slot around the central hole; a positive plate guide hole is penetrating the end cover; a lower end face of the end cover is tightly pressed on the negative plate and the locating seat; the end cover is detachably connected with the upper opening of the shell and a cover edge of the end cover cooperates with an end surface of the upper opening of the shell; the positive plate is circular and is mounted in the positive plate slot of the end cover; characterized in that: the battery is a lithium ion battery; a lower end face of the through hole for positive plate and a lower end face of the through hole for negative plate are respectively arranged with a positive guide block and a negative guide block; the positive guide block and the negative guide block are supported by and cooperated with an end part of the battery cell; a positive conductive plate of the positive plate is passed through the positive plate guide hole of the end cover and the through hole for positive plate to cooperate with the positive connecting plate; the negative plate is disposed in the mounting hole of the locating seat and having a negative conductive plate thereof passed through the through hole for negative plate to cooperate with the negative connecting plate; the positive contact extends out from the contact extending hole. wherein the shell is a cylinder having an upper opening and a contact extending hole on a center of a bottom plate of the shell; an upper end face of the locating seat is arranged with a mounting hole of the negative plate; the locating seat further includes a through hole for positive plate and a through hole for negative plate while the through hole for negative plate communicates with the mounting hole; the end cover is mounted with a central hole and an upper end face thereof is arranged with a positive plate slot around the central hole; a positive plate guide hole is penetrating the end cover; a lower end face of the end cover is tightly pressed on the negative plate and the locating seat; the end cover is detachably connected with the upper opening of the shell and a cover edge of the end cover cooperates with an end surface of the upper opening of the shell; the positive plate is circular and is mounted in the positive plate slot of the end cover; characterized in that: the battery is a lithium ion battery; a lower end face of the through hole for positive plate and a lower end face of the through hole for negative plate are respectively arranged with a positive guide block and a negative guide block; the positive guide block and the negative guide block are supported by and cooperated with an end part of the battery cell; a positive conductive plate of the positive plate is passed through the positive plate guide hole of the end cover and the through hole for positive plate to cooperate with the positive connecting plate; the negative plate is disposed in the mounting hole of the locating seat and having a negative conductive plate thereof passed through the through hole for negative plate to cooperate with the negative connecting plate; the positive contact extends out from the contact extending hole. the battery is a lithium ion battery; a lower end face of the through hole for positive plate and a lower end face of the through hole for negative plate are respectively arranged with a positive guide block and a negative guide block; the positive guide block and the negative guide block are supported by and cooperated with an end part of the battery cell; a positive conductive plate of the positive plate is passed through the positive plate guide hole of the end cover and the through hole for positive plate to cooperate with the positive connecting plate; the negative plate is disposed in the mounting hole of the locating seat and having a negative conductive plate thereof passed through the through hole for negative plate to cooperate with the negative connecting plate; the positive contact extends out from the contact extending hole.