Systems and methods that detect a loss of charge associated with a climate controlled environment are described in the present disclosure. In various embodiments, a controller receives operating condition parameters associated with a climate-controlled environment. The controller determines whether a compressor is operating in a first mode of operation or a second mode of operation. The controller applies a first model to the operating condition parameters when the compressor is operating in the first mode of operation to represent a loss of charge associated with the climate-controlled environment and applies a second model to the operating condition parameters when the compressor is operating in the second mode of operation to represent the loss of charge associated with the climate-controlled environment.