Tesla Motors Inc (TSLA) receives patent for detection of over-current shorts in battery pack using pattern recognition

Posted Jan 9, 2014

Tesla Motors Inc (NASDAQ:TSLA) has received a patent that was invented by Arthur Weston and Scott Ira Kohn. The patent #8618775 is called “Detection of over-current shorts in a battery pack using pattern recognition.”
This invention is related to the detection of and response to potentially hazardous conditions in an electric vehicle battery pack, specifically related to detecting and responding to potentially hazardous over-current “due to internal short circuit to limit possible excessive thermal conditions of the individual battery cells and modules.”

Battery packs that are used with electric vehicles storage a large amount of energy in a small space and produces high energy densities. The battery packs are designed for providing high levels of safety and stability. However, there are situations where a portion of a battery pack experiences a local thermal issue that generates significant heat. If the temperature is great enough, the local thermal condition could transform into a runaway thermal condition that affects wide areas of the battery pack.

“Prior art battery packs contain fusing architectures designed to both actively and passively interrupt external or internal short circuits above normal operating currents. Most short circuit protection devices have a very short thermal time constant and are only effective above a predetermined current. However, an electric vehicle may only be capable of sustaining operation at its maximum current for a short period of time before internal components, including the battery cells, heat to near their temperature limits,” states the patent.

Tesla aims to prevent the affected areas from overheating by summoning the maximum heat rejection capabilities of the systems until the short ceases and the elements that are affected cools down.

Tesla Motors dealt with a PR issue when 3 Tesla Motors vehicles caught on fire in late 2013. One of the accidents was due to reckless driving. The other two had to do with an object impaling the battery packs. No one was injured in any of these incidents.