KANEX – EXTINGUISHER – AVD Lithium-ion batteries are popular because of how much power they can put out at a given size and weight in comparison to old lead type batteries. However, lithium-ion batteries are extremely sensitive to high temperatures and inherently flammable. These battery packs tend to degrade much faster than they normally would, due to heat. If a lithium-ion battery pack fails, it will burst into flames and can cause widespread damage.