To provide a charge method which can attain full charge without the possibility of overcharge, when a battery voltage does not reach a reference voltage, on account of the discharged state of a battery or the change of battery temperature or some other causes.
When the charge time T1 of a first step until a voltage reaches a reference voltage Vref is shorter than a reference time Tref, the charge time T2 of a second step is changed over to a constant time TS (T2=TS) which is imparted to charge of the second step for attaining the full charged state and shorter than a constant time TC. When the charge time T1 of the first step reaches an upper limit time determined by previously measured discharge current amount, charge of the first step is compulsorily finished.
KURIMOTO TAKASHI
TERADA KOJI
MIYAZAKI SHUNICHI
