Patent ID: 6127804
Filing Date: 2000-10-03
Classification: H01M,H02J,Y02E

Abstract:
A battery charging system, comprising:A) a power supply having a power input, wherein the power supply is capable of delivering a constant current output;B) A lithium based rechargeable battery cell having a termination voltage;C) A linear regulated charging circuit coupled in series between the power supply and the lithium based rechargeable battery cell, wherein the linear regulated charging circuit provides a constant and limited value of charging current until the termination voltage of the lithium based rechargeable battery cell is reached, wherein the linear regulated charging control regulates at the value of the termination voltage;D) A power switch having a control terminal coupled in parallel with the linear regulated charging control circuit;E) An upper voltage reference and a lower voltage reference; andF) An ionic relaxation charging control circuit coupled to the control terminal of the power switch wherein the ionic relaxation control circuit closes the power switch when the voltage of the lithium based rechargeable battery cell is below the lower voltage reference and opens the power switch when the voltage of the lithium based rechargeable battery cell is above the upper voltage reference.