As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU NOT STARTING. REPEAT APU STARTING PROBLEM WITH NO INDICATED FAULTS NOTED. TROUBLE SHOOTING FOUND CHARGER & BATTERY AT FAULT. REPLACED APU BATTERY IAW MM 24-31-03 & REPLACED APU BATTERY CHARGER IAW MM 24-31-04. SYSTEM OPERATIONS CHECKED GOOD. APU STARTS MUCH FASTER & NO LONGER REQUIRES EXCESSIVE LONG RECHARGE.