▎ 摘　　要

NOVELTY - The method involves providing a Hall effect sensor (20) comprise a graphene conductor for measuring a magnetic field, and positioning the sensor at a position adjacent to a face of a cell. A load is applied to the cell, and an output of the sensor is measured. The sensor is moved from the former position to another position adjacent the face of the cell. The output is measured at a location, and is monitored. A change in the magnetic field indicative of cell failure is identified, and a location in the cell of the failure is determined. The magnetic field is converted to a local current density. USE - Method for field mapping cell under load of rechargeable battery e.g. individual cell, battery and battery pack. ADVANTAGE - The Hall effect sensor is able to detect current densities in the cell with high sensitivity and across a wide range. The risk of localised defects in cell being missed is reduced, since an even distribution over the face of the cell is provided. The safety and efficiency of the battery is monitored based upon temperature data at an overall pack level. The overall health of the entire cell is indicated, since the map of cell is allowed to be evenly distributed to give an indication of the overall health. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a Hall Effect sensor; (2) an apparatus for field mapping a cell under load; and (3) an assembly for field mapping cell under load of rechargeable battery. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of an apparatus for monitoring a cell. Integrated measurable cell (10) Current tab (12) Hall Effect sensor (20) Cell (100)