Abstract: The invention deals with a sensor for sensing electrolyte creepage in a battery, a circuit comprising such sensor, and a battery connected to such circuit, with an application to an electrical circuit comprising the sensor and connecting a monitoring equipment to a to battery. The sensor element is adapted for being connected within an electrical circuit 1 connected to a battery 2, said battery comprising one or more electrochemical cells containing an electrolyte, wherein the sensor element comprises a electrical conductor element whose at least one electrical property varies when in contact with the electrolyte, such as to allow, when the sensor element is connected in a circuit, detection of an electrolyte creepage from a an electrochemical element of a battery 2 connected to the circuit 1 by measurement of the variation of the one electrical property of the conductor element.