The battery module and the inverter itself

3DMax 2014
Vray 3.40.01
Corona 1.6

https://www.tesla.com/en_GB/powerpack?redirect=no 

Who works in the V-Ray version is lower than 3.1. Be careful the materials in the BRDF section are Microfaset GTR (GGX) if your version is older than 3.1 then the BRDF field will be empty. Choose Blinn Phong or Ward – which is preferable for you.
For Corona render it is recommended to put version no lower than 1.5 since the glossiness of materials is adjusted to the PBR.