Patent ID: 8742729

Claim:
A rechargeable battery, comprising: a renewable energy storage device coupled to a high density capacitor and an integrated circuit: the high density capacitor connected between a reference voltage terminal and a first node carrying a first voltage; and the integrated circuit comprising: a band gap circuit for generating a band gap voltage according to the first voltage; a first detecting unit for measuring the first voltage according to an input charging voltage and determining whether to apply the input charging voltage to the high density capacitor; the first detecting unit comprising a first comparator for comparing the input charging voltage with the first voltage to generate a first control signal; and a first switch for connecting the first node with an input terminal carrying the input charging voltage according to the first control signal; a voltage divider connected in parallel to the high density capacitor and having a second node carrying a second voltage; a second detecting unit for measuring the second voltage according to the band gap voltage and determining whether to connect a third node to the first node; the second detecting unit comprising a second comparator for comparing the band gap voltage with the second voltage to generate a second control signal; and a second switch for connecting the first node to the third node according to the second control signal; and at least one low dropout voltage regulator, each being connected to the third node and generating a specified voltage output and a specified current output according to the band gap voltage and the first voltage; wherein an amount of charge[s] stored by the high density capacitor after fully charged is given by Q=C×(V chg −V min ), where C denotes a capacitance of the high density capacitor, V chg denotes a magnitude of the input charging voltage and V cmin denotes a predetermined minimum of the first voltage that the third node remains connected with the first node.