What was found
NO WRI IN COMPUTER AT THIS TIME. BATTERY DISCHARGING ALERT, CREW DECLARED AN EMERGENCY. LEVEL BATTERY DISCHARGE OCCURRED 38 MIMUTES AFTER TAKE OFF. ACFT WAS AT FL 390 , .84 MACH . NO OTHER ADVERSE ELECTRICAL PROBLEMS NOTED . ALL FLIGHT DECK AND CARGO TEMPS NORMAL . DISCHARGE WAS INTERMITTANT TO CONSTANT . LANDED. PERFORMED TROUBLESHOOTING IAW FIM 24-30-19-00. FOUND FAULT TO BE BATTERY CHARGER . R&R BATTERY CHARGER IAW MM 24-34-01-2 . OPS TESTED OK .