As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) WHILE CHANGING A BATTERY PACK IN AN ELT, THE CASING WAS NOTICED TO BE CRACKED ATTHE SCREW HOLES. IF THE BATTERIES HAD LEAKED THE ACID COULD LEAK ON TO THE BATTERY TRAY & THE AIRCRAFT SURROUNDING STRUCTURE. THIS HAS HAPPENED TWICE BEFORE. WE HAVE AN INSPECTION INTERVAL OF 50 HRS. ON THE BATTERY TRAY AND ELT MOUNTING.