BST (Battery Safety Terminal) COOPER S Only

The BST is installed in the COOPER S due the battery location in the luggage compartment. Because of this, MINI implements a comprehensive electrical fusing system in the MINI with the goal of minimizing the danger of short circuits in the event of a severe accident.

To achieve this, the vehicle's electrical system was divided into the starter circuit and the vehicle system supply circuit. The vehicle system supply circuit is protected against short circuits by means of special high current fuses. The cable to the starter and the alternator - which cannot be protected by conventional methods of fusing since it must carry very high current when the starter is engaged and is permanently subjected to voltage - is protected by the Battery Safety Terminal (BST). This fusing method practically excludes the danger of a short circuit in the event of a severe accident.

The BST consists of a conventional clamp that is screwed onto the positive terminal from above and connected with a hollow cylinder. A propellant charge is stored in this hollow cylinder. Just as with the airbag and seat belt pre-tensioner, this pyrotechnic device is controlled and ignited from the MRS control module. The triggering strategy is also the same as for the triggering of the airbag, and it possesses identical protection logic. The overall unit is enclosed in a plastic shell that captures the cable if it is forced out and locks it so that a renewed contact is no longer possible.