Or, just read what is written by people who have years of professional experience handling testing and designing Lithium battery products.
After the fire erupts you should not throw a small amount of water at the fire because that will augment the fire, as the FAA document states. If you can drown out a single cell fire immediately then do try to. However if the pack is a large capacity multi-cell pack and its starting to go up in flames the rest of the pack will go in just a few seconds. There isnt time to save the pack or other cells. Instead its better to understand the situation.
1) disconnect the battery from the charger OR the charger from the power source. If the charge leads are short and its dangerous to disconnect the battery then unplug the charger instead.
2) once the pack is hot and at least one cell is puffed you have time to respond. Unplug the battery right away and set it outside 10 feet away from anything flammable. Let it cool then cut the leads and drop it in the salt water bucket.
3) leave the area until the battery pack has finished reacting then respond as needed with a fire extinguisher or sand or a water hose if you can do it safely. Generally speaking if the materials surrounding the area are not highly flammable then there is time to respond after the lithium has consumed itself.
4) ventilate the area immediately to get the toxic fumes out if you can do it safely.
You can attack an erupting pack if your quick and accurate in your actions to contain and snuff the pack out. If your present and notice the pack is puffed all you have to do is unplug it and determine if its safe to move it. You can even simply drop the pack on the floor in an open area of the room as long as the floor is not carpet or tile. Hardwood floors will not catch fire with a pack sitting on top of it but there will be some damage (yes prolonged exposure to fire will result in a fire but other factors must be present before a flat hardwood face will catch fire and sustain itself). In a shop the concrete floor will be fine. Its a better option of the poor options you have in an emergency inside your home (which you should not be doing anyway)
In the shop;
1) have a 5 gallon bucket of sand in your shop area AND a 5 gallon bucket of salt water. The sand will help to contain a fire if you can pour it on the pack and the water is for disposal of damaged packs to make them inert.
2) have a Chemical Fire Extinguisher on hand rated ABC and it should be at least 10 pounds.
Never charge a pack on top of flammable materials or near other chemicals. Make a dedicated bench charging area and keep it neat and clutter free.
The part that stays very hot for quite a while after the lithium burns off are the many layers of copper sheets used to build a cell. You can use water to cool this off after the chemical fire has finished, just as the FAA document suggests. What they dont say is how bad the fumes and smoke are. You cannot approach a lithium fire without breathing equipment safely. Even after the event the smell will take your breath away its very intense. If your standing upwind of a pack on fire your ok and you can respond to the fire no problem in an out door situation.
If a pack is having a total failure and all cells are puffed the pack will expand significantly. A 3-4mm thick cell can become 10mm or more in seconds. Multiply that by 3/4/5 cells and the pack will take up a lot of space in a container very quickly. The volume of the container should be ample enough to account for the packs potential physical size and its potential energy. A box measuring 9x6x4 inches can handle a single 3S 3000mah pack failure or any combination of capacity and voltage not to exceed 60 Watt Hours. Above this rating the container must be larger or the pressure inside will cause the container to explode. The container cannot be air tight or it will explode due to expanding gases. This is tried and tested by myself and I have destroyed many packs of all sizes in the pursuit of this info.
Storing a couple, three, packs in one container capable of withstanding the failure of all the packs it is storing is OK. Exceeding the capacity of the container will potentially result in an explosion.
Look there are a million ways to dissect this topic and go round and round but some common sense and paying attention to what your doing will be the best way to not have this unfortunate conversation.
1) make sure you have the right charge profile for the pack your charging NOW not the last time you used the charger.
2) make sure you have good connections and the plugs are not worn out or damaged.
3) make sure the plug solder joints are not cold solder joints
4) make sure you know the packs balance voltage between cells - that doesn't mean you have to balance charge a pack every cycle it just means you need to know the packs condition or state. Thats especially important at the start of the flying season.
Do all of the above 4 steps AND have a proper charging area with sand, salt water and an extinguisher and I will promise you success and safety with Lithium battery packs.