Continental launches sensors to make EV batteries safer

Continental is launching two new sensors for electrified vehicles, the Current Sensor Module (CSM) and the Battery Impact Detection (BID) system. Both new solutions focus on protecting the battery and/or on battery parameter retention. 

Within 2022, Continental will begin to manufacture the all-new high-voltage Current Sensor Module (CSM). This compact modular sensor design measures the current and simultaneously detects temperature. Both values are highly relevant as input for the battery management. Another innovative element of battery protection will be brought into the market by Continental: The Battery Impact Detection (BID) solution is a light-weight alternative to heavy underfloor “armoring” against damage. 

To support strict functional safety requirements, the CSM is available as a two-channel sensor, measuring current independently by integrating shunt technology and hall technology in a compact, single unit. The BID in combination with a lightweight structure detects underfloor impacts and alerts the driver if a stop at a garage is necessary as a result. In comparison to current metal underfloor protection the BID solution can save up to 50 percent of weight.

Laurent Fabre, Head of Passive Safety and Sensorics Segment at Continental says, “Protecting the battery and retaining its performance, for instance, are two additional tasks in electrified vehicles. The Current Sensor Module and Battery Impact Detection solutions serve both purposes.”

“A lithium-ion battery has an optimum temperature span in which it is very safe and ages very slowly,” says Horst Gering, Program Manager in the Passive Safety and Sensorics Segment. “However, fast charging the battery is a tradeoff between keeping the battery safe and healthy and limiting the duration of charging. This is best done on an exact data basis.” Also, the CSM helps to calculate the precise remaining range by monitoring current consumption.

 The CSM fully supports ASIL D on system level. The production of the CSM will commence within 2022 for a global automaker’s state-of-the-art electric vehicle. The first product is part of a modular sensing platform which is scalable for additional features such as voltage measurement and number of measurement channels.

Detecting battery impact matters
Electric vehicles are fitted with a large and often heavy cover to protect the battery compartment from the underside. However, if an impact occurs, it will be up to the driver to judge whether the car needs to be checked at a garage. “This is not a satisfying situation as there is poor visibility underneath a car, plus it takes a trained eye to assess the true damage”, says Johannes Clemm, Managing Director Continental Safety Engineering International in Alzenau. To help the situation and make a lightweight underfloor protection feasible, Continental has developed the pressure-sensor based Battery Impact Detection solution. “In addition, the BID identifies the area of the damage, so the battery management can empty the cells in that area to prevent any risk of fire,” Clemm adds.

The BID covers two typical impact risks: One is low-speed ground contact, for example, during parking maneuvers when the vehicle slowly rolls over a curb and hits the ground. During this type of event, the BID signal could also be used to trigger a fast-acting active suspension system to temporarily increase the underfloor clearance in order to mitigate the damage. The other use case is high-speed intrusion which can be caused by swirled up heavy objects such as rocks or lashing straps on the road. Given the speed and impact, these types of objects can damage the underfloor and potentially even penetrate the battery structure.

The pressure sensor satellites used in the BID derived from the proven Pedestrian Protection System (PPS pSAT) which has been in serial production and applied in millions of vehicles for more than ten years. The time difference between the signal’s arrival at the two pressure satellites at both ends of the tube makes it possible to calculate the area of the impact.