I imagine many are. But in small spaces with poor ventilation (e.g. vehicle interiors) that might not be enough. The sealed batteries still have a vent for the gas to leak (in a controlled manner).
But besides that, li-ion batteries have more energy per weight, are more efficient at storing energy, and can be discharged to a farther level without negatively impacting the battery.
https://electronics.stackexchange.com/questions/175649/are-s...
But besides that, li-ion batteries have more energy per weight, are more efficient at storing energy, and can be discharged to a farther level without negatively impacting the battery.
Sorry for the annoying popups, this is the best source I could find: https://news.energysage.com/lithium-ion-vs-lead-acid-batteri...