A battery box consists of the structure - usually a cage-like construction of structural metal, a liner, and insulation.

The only one that is absolutely required is the structure. The others are a good idea if you want to keep the batteries clean and warm. The structure is usually a cage-like construction of angles and supports.

CanEV builds sheet metal or aluminum boxes which act as the structure and lining. The structure used to restrain the batteries must be capable of restraining them and keeping them from entering the passenger compartment in the event of an accident. It should be either welded or bolted to the structure of the car. NEDRA (National Electric Drag Racing Association) recommends designing the cage to withstand a load of 8G’s (8 times the total weight of the cage and all its contents) forwards, backwards, and to each side, as well as 4 G’s upwards and downwards. It is acceptable if the structure deforms during a crash so long as it restrains the batteries.

CanEV recommends installing the battery boxes under the rear seat when possible. This is usually where the gas tank was originally located and considered a safe location in the case of an accident. This location is also low in the car making it more stable than a battery pack that is located above the floor. Large battery packs should not be placed behind the rear wheels as it will have a negative effect on handling.

Sometimes a battery heating system is installed for use in cold climates. Various schemes have been used for this, but it usually consists of some sort of tape or pad heating unit, with a remote temperature probe and a thermostat.