Here is the LA Times article
https://www.latimes.com/california/story/2019-09-05/what-caused-fire-aboard-the-conception
They write about cell phone batteries in this article. There are bigger Li-ion battery packs in scooters / DPV. On one of my liveaboard trips, there were many scooters on the boat. People brought their own, some had home-made battery packs. Some had trouble with the battery packs, had to fix it, rewire, ...