"Instead of using a mechanical pull to open the doors, Teslas have a button or a handle that triggers an electric motor, which disengages the latch. The doors are not powered by the car’s main battery, relying instead on a second low-voltage battery. If that smaller battery fails, the doors will not open, noted Transport Canada in its collision investigation."

https://www.thestar.com/news/canada/trapped-in-a-tesla-why-electronic-doors-are-at-the-centre-of-the-investigation-into/article_a869d10a-89ef-4276-8744-70c86551cb66.html