What was found
AT APPROX 80KTS ON TAKEOFF ROLL CREW OBSERVED A MASTER WARNING LIGHT & SAW A RED ANNUNCIATOR LIGHT, BATTERY OVERHEAT. ABORTED THE TAKEOFF & UNEVENTFULLY TAXIED CLEAR OF THE RUNWAY. THE APU HAD SHUT ITSELF DOWN & THE APU FIRE DETECTION CB HAD POPPED. NOT ABLE TO DUPLICATE BATTERY OVERHEAT CONDITION & REPLACED THE BATTERY & THE BATTERY TEMP SENSOR AS A PRECAUTIONARY MEASURE. BATTERY HAS 191 HRS & 134 CYCLES SINCE INSTALLATION 30 MARCH 2014 TEMP SENSOR HAS 1278 HRS & 865 CYCLES SINCE INSTALLATION 18 OCTOBER 2012. REPAIRED CHAFED WIRE IN TAIL CONE CAUSING APU CB TO POP. GND RUN-UPS & OPS CHECKS WERE SATISFACTORY & ACFT RETURNED TO SERVICE.