An electronic device may generate content that is to be displayed on a display. The display may have an array of liquid crystal display pixels for displaying image frames of the content. A charge accumulation tracker may analyze the image frames to determine when there is a risk of excess charge accumulation. The charge accumulation tracker may implement a physically derived circuit model of the pixels. A charge accumulation input response matrix and a charge accumulation state response matrix for the model may be stored in look-up table circuitry and used in computing a current charge accumulation state based on current pixel voltage information and previous state information. The impact of temperature, backlight illumination level, frame duration, and other factors may be taken into account in evaluating the current charge accumulation state.