What was found
AIRCRAFT DEPARTED KPSP, DURING CLIMB OUT AT 14,000 FEET THE AMBER "EMERGENCY BATTERY OVERHEAT" LIGHT CAME ON. CREW CHECKED THE BATTERY TEMPURATURE AND THE READING WAS 140 DEGREES F AND CLIMBING. THE CREW PER THE CHECKLIST TURNED OFF THE "EMERGENCY BATTERY". THE CREW LEVELED OFF THE AIRCRAFT OFF AT 15,000 FEET AND THE "EMERGENCY BATTERY OVERHEAT" LIGHT TURNED TO RED. TEMPERATURE OF THE BATTERY WAS 160 DEGREES F AND CLIMBING. CREW CHECKLIST SAYS TO LAND AS SOON AS POSSIBLE THE CREW RETURNED TO KPSP AND LANDED. ON THE GROUND THE "EMERGENCY BATTERY WAS CHECKED AND DETERMINED NOT TO BE NON-EMERGENCY SITUATION. MAINTENANCE FOUND A FAILED BATTERY TEMPERATURE SENSOR, REPLACED BATTERY TEMPERATURE SENSOR WITH NEW. OPS CHECKED AND AIRCRAFT RETURNED TO SERVICE.