error message for battery usage

joanmt wrote:

macpro 15" retina 2015 has a loud "fan" sound and the battery shows an error message

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To expand upon @leroydouglas' suggestion.....if the battery is bad, then the temperature sensor within the battery may not be registering. If a Mac cannot communicate with all the sensors, then the Mac will run the fan(s) at high speed to protect the Mac from overheating.