batteries in EVs can
fail due to:
Manufacturing defects, stress from vibrations, electrical short, etc.
undergo thermal runway, increasing temperature and pressure
and also releasing flammable gases.
EV fires can be quite dangerous.
But you can prevent them.
Don’t charge EV batteries immediately after use.
Let the battery cool first.
Charge detachable batteries only after removing them.
And keep them in cool and dry areas.
Finally, only use authentic batteries for your vehicle.