This is a myth cause by the confusion about lithium metal reacting with water, but the cells only contain lithium ions suspended in a liquid electrolyte. They don’t contain lithium metal. (More confusingly some other battery types do contain lithium metal)
I have read fire departments and cell manufactures recomending a shit load of water. As the only way to put them out is to reduce the temperature below thermal runaway. It also prevents it spreading to other flammable items or cells.
When you have several packs next to each other like in this situation, one burns, makes the one next to it hot and then it goes into thermal run away. You end up with a slowly moving fire from one end of the pack to the other.
In this case he managed to save the other cells, with sand it probably would have been the entire pack.
I think sand is good though for small packs that can be completely covered. Though it only contains the fire shooting out but does not put them out due to lack of oxygen. They still burn until all the fuel is used up.
Sand is a good option if you don’t have a shit load of water and you just happen to have a big bucket of sand.
From batteryuniversity, they are pretty decent sorce.
What to Do When a Battery Overheats or Catches Fire
If a Li-ion battery overheats, hisses or bulges, immediately move the device away from flammable materials and place it on a non-combustible surface. If at all possible, remove the battery and put it outdoors to burn out. Simply disconnecting the battery from charge may not stop its destructive path.
A small Li-ion fire can be handled like any other combustible fire. For best result use a foam extinguisher, CO2, ABC dry chemical, powdered graphite, copper powder or soda (sodium carbonate). If the fire occurs in an airplane cabin, the FAA instructs flight attendants to use water or soda pop. Water-based products are most readily available and are appropriate since Li-ion contains very little lithium metal that reacts with water. Water also cools the adjacent area and prevents the fire from spreading. Research laboratories and factories also use water to extinguish Li-ion battery fires.
Crew can’t access the cargo areas of a passenger aircraft during flight. To assure safety in case of a fire, planes rely on fire suppression systems. Halon is a common fire suppressant, but this agent may not be sufficient to extinguish a Li-ion fire in the cargo bay. FAA tests found that the anti-fire halon gas installed in airline cargo areas can’t extinguish a battery fire that combines with other highly flammable material, such as the gas in an aerosol can or cosmetics commonly carried by travelers. However, the system prevents the blaze from spreading to adjacent flammable material such as cardboard or clothing.
A large Li-ion fire, such as in an EV, may need to burn out. Water with copper material can be used, but this may not be available and is costly for fire halls. Increasingly, experts advise using water even with large Li-ion fires. Water lowers combustion temperature but is not recommended for battery fires containing lithium-metal.
https://batteryuniversity.com/learn/article/safety_concerns_with_li_ion
Its a hard situation when your skating around in public you cant carry a 50ltr of water or a huge extinguisher.
those boxes all stuffed with batteries?
what´s the range and what´s the weight???
Sounds cool. Do a thread on it my friend
