| abstract |
In a secondary battery charging method, constant current charging is performed until a first predetermined voltage V 0 is attained, constant voltage charging is then performed at the first predetermined voltage V 0 , the first constant voltage charging is completed when a charge current becomes (I n −ΔI n ) from I n , and then n is incremented by one; and constant voltage charging is performed at a voltage V n =V n-1 +ΔV n , a step of completing the n-th constant voltage charging when the charge current becomes (I n −ΔI n ) from I n is repeated by incrementing n by one, and the N-th constant voltage charging in which a value of the voltage V n reaches a second predetermined voltage V N (>V 0 ) is completed to terminate the constant voltage charging. |