I have one or two under the bed in the back of my van. Just be sure to get the right class of extinguisher.
https://www.femalifesafety.org/types-of-extinguishers.htmlClass A fires are fires in ordinary combustibles such as wood, paper, cloth, rubber, and many plastics.
Class B fires are fires in flammable liquids such as gasoline, petroleum greases, tars, oils, oil-based paints, solvents, alcohols. Class B fires also include flammable gases such as propane and butane. Class B fires do not include fires involving cooking oils and grease.
Class C fires are fires involving energized electical equipment such as computers, servers, motors, transformers, and appliances. Remove the power and the Class C fire becomes one of the other classes of fire.
Class D fires are fires in combustible metals such as magnesium, titanium, zirconium, sodium, lithium, and potassium.
Class K fires are fires in cooking oils and greases such as animal and vegetable fats.
Most vans will see class A and B fires. However, depending on he equipment in your van and how you use it, you might have a C, D, or K class fire.
Make sure whatever extinguisher(s) you get is appropriate for the class of fires that may break out in your van or site.