The purpose of this utility invention is to provide a rechargeable battery, targeting the above problem. The usb charging device facilitates battery storage and use while igniting the charging circuit and protecting battery charging. To achieve the above objectives, this practical new type of technology option is: Rechargeable battery USB charging charger case, charger case with a charging plug installed on the front of the charger case, and two side settings of the charger case are battery charging and slots, and a charging spring slice is installed in the battery charging and slot to charge through the battery. Ann slot pushes the floating drift battery into the charging spring seat. The charging spring seat is connected to the charging control circuit. There is a battery storage cavity between the above electric full charging arm slots. The battery storage cavity has a pad on the front and a pad on the back. Set the port to use. These charger cases set the cover panel on the port of use. In addition, the specified charge control circuit is as follows. The CHRG interface of a single sheet machine connects the red markings in series. Lamp and resistor vs. +5V potential difference connection, single-sheet mechanical donne interface connects the +5V green light and resistor in series. Potential difference connection, single sheet machine BAT battery anode is charged to the end pitch, and the FB end is connected to the battery anode charged by resistor. The monocoder grounds the other end. Furthermore, the charge control circuit is two types that independently control the charging process of the floating battery. The charger housing sets the charging status indicator above the internal charging control circuit. Furthermore, the gasket is set on a filling spring sheet, and the material is an insulating material. The beneficial effects of this practical new type: 1.This invention device optimizes the circuit when the battery voltage is low. Charging current at 2.9 volts
