What was found
AT APPROX 2500 AGL, WELL AFTER LANDING GEAR RETRACTION, THE BATT CHG ANNUNCIATOR ILLUM AND REMAINED LIGHTED FOR 15-20 SEC, THEN EXTINGUISHED. ABNORMAL CKLIST PERFORMED, NO FURTHER INCIDENT. THIS BATT CHG ANNUNCIATOR ILLUM WRITEUP IS CONSIDERED A NUISANCE AND A SEVERE DISTRACTION TO THE PILOTS. REMOVED AND REPLACED BATTERY, ENG RUN SHOWS GENS PARALLELED.