Yes, a temperature sensor is built into every negative post connection from the Vigilant. It is recognized in the battery industry that the negative post of the cell is the most sensitive to internal temperature variation, and if ‘acid creep’ is experienced it is inevitably at the negative terminal post first. The negative post is often at a slightly higher temperature than the positive post and in any case terminal posts are a much better indicator of internal temperature than the plastic cell casing, which is a thermal insulator and influenced by the ambient temperature. The Vigilant sensor is designed to have an excellent thermal connection to the negative post and is also insulated against the effects of changes in the ambient.