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Tesla updates battery software on Models S and X after Hong Kong fire

The update affects the battery's thermal management systems and its charge control systems and is being rolled out on Wednesday.

2017 Tesla Model X
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2017 Tesla Model X

Tesla is sending out a software update to Models S and X to improve battery life and safety.

Tim Stevens/Roadshow

Tesla announced on Wednesday that it had begun rolling out software updates to Models S and X that promise to extend battery life and safety. The update affects the thermal management system for the cars' battery packs, and stems from the recent fire in Hong Kong of a Tesla in a parking structure. Tesla told Roadshow that this update was created out of "an abundance of caution" after that incident.

"We currently have well over half a million vehicles on the road, which is more than double the number that we had at the beginning of last year, and Tesla's team of battery experts uses that data to thoroughly investigate incidents that occur and understand the root cause," Tesla said in a statement. "Although fire incidents involving Tesla vehicles are already extremely rare and our cars are 10 times less likely to experience a fire than a gas car, we believe the right number of incidents to aspire to is zero."

The over-the-air software update adjusts charging and cooling settings within the battery management system, likely to manage each cell's temperature and level of charge more efficiently to help prevent situations where the cell could be stressed. Overcharging of individual cells is a leading cause of pack fires in modern EVs and isn't by any means specific to Tesla. Although pack fires are relatively rare when compared to internal combustion engine fires, they are simply one of the main drawbacks of lithium-ion battery chemistry.

Tesla assured Roadshow that this update wouldn't be noticed by most of its customers in operation and that in addition to improving safety in the long-term, it should also help improve the life of Tesla's already notoriously long-lived packs.

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Kyle Hyatt Former news and features editor
Kyle Hyatt (he/him/his) hails originally from the Pacific Northwest, but has long called Los Angeles home. He's had a lifelong obsession with cars and motorcycles (both old and new).
Kyle Hyatt
Kyle Hyatt (he/him/his) hails originally from the Pacific Northwest, but has long called Los Angeles home. He's had a lifelong obsession with cars and motorcycles (both old and new).

Article updated on May 15, 2019 at 1:23 PM PDT

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Kyle Hyatt Former news and features editor
Kyle Hyatt (he/him/his) hails originally from the Pacific Northwest, but has long called Los Angeles home. He's had a lifelong obsession with cars and motorcycles (both old and new).
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