The addition of a graphite only coating does reduce the temperature of the cell, on average, compared with an uncoated cell (Figure ). Graphite has a high thermal conductivity and has been used previously to enhance the use of PCMs in BTMS to allow for more efficient heat dissipation away from the cell. Graphite was added to the coating and showed better heat dissipation than a coating without graphite, Figure . The inclusion of graphite was used to prevent the coating having a low thermal conductivity which would be detrimental to the coating controlling the temperature of the cell. When designing a BTMS using PCMs, the thickness of the applied PCM is an important factor in its effective application. Figure shows the relationship between coating thickness and temperature increase. For coatings less than 1.5 mm thickness there are no significant difference between coatings with and without the PCM present. The coatings do not contain enough PCM to take up a significant amount of heat compared to the heat dissipation which is provided by both the shell material and the graphite additive. For coatings of 1.5 mm thickness and higher, the mass of the PCM present is significant enough to absorb more heat than would be dissipated resulting in the observed reduction in the temperature rise. Additionally, the standard deviation of the thicker coatings also narrow. Since dip coating can result in uneven coatings, at thicker coatings there is more even distribution of material resulting in more consistency between tests. showing that more heat is being absorbed by the PCM at this thickness (Figure ). To further assess the efficacy of the coatings, the previously described modified New European Driving Cycle (m-NEDC) was used test the cell coatings under conditions more representative of standard driving. As previous, an uncoated cell was initially analysed to determine baseline The effects of different coating thicknesses were also explored using this m-NEDC cycle (Figure ). As was observed under the previous testing regime, thinner coatings (0.6 -1.0 mm) containing both PCM capsules and graphite show limited improvement compared to coatings containing only graphite. However, for coatings of >1.1 mm thickness, the positive effect of the PCM capsules on the thermal behaviour of the cell is much more pronounced. The required coating thickness for effective thermal management is thinner than in the previous test where thermal performance improved after 2.0 mm thick coating was applied. However, unlike the previous testing regime, after 2.0 mm thick coatings a diminishing return is observed. From Figure , the 3.0 mm and 3.5 mm thick coatings are on average less effective at controlling the temperature. At this stage the thickness of the coating is detrimental to the efficient dissipation of heat away from the cell.