As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BATTERY CHARGER APU STATUS MESSAGE. REPLACED CHARGER AND BATTERY AS A PRECAUTION. ACCOMPLISHED FIM 24-34 TASK 803 BATTERY STILL AT 25VDC. REPLACED APU BATTERY PER MM. REPLACED APU BATTERY CHARGER PER MM. APU BATTERY CHARGER CHECKED OK. 28 VDC CONFIRMED.