Why does US aviation forbid to carry spare batteries in checked baggage?

Increasing risks from shipping Lithium batteries on aircraft have forced the FAA to introduce new regulations.

The reason the US airline does not allow to carry spare batteries in checked baggage

A few days ago, the US Federal Aviation Administration (FAA) issued a ban to carry spare batteries in checked baggage. In fact, before the FAA ban, some major US airlines, such as Delta Air Lines and American Airlines, had different rules about not allowing backup batteries that were popularly Lithium-type. ion on the plane.

These rules and prohibitions stem from concerns about flight safety when there are some tests showing that the ability of this Lithium-ion battery to explode in the aircraft's luggage compartment is quite high. .

Lithium batteries exploded in quantity

The Backup Battery Market has grown very fast in the last 2 years, along with the development of smartphones. While smartphones are getting stronger, phone batteries don't have any technological breakthroughs yet, so the battery market for battery backup is understandable.

Not until now, the risks and risks of this battery explosion are mentioned. Fortunately, so far, cases of fire on aircraft caused by this battery have only been recorded as rare phenomena, but not often. However, these risks have become increasingly clear as the number of Lithium batteries produced is increasing rapidly. In 2013, about 4.8 billion cells of Lithium-Ion batteries were produced, and it is expected that this number will increase to 8 billion by 2025. With such a large number of batteries shipped, safety concerns When flying with these products it is clear that there is a basis.

If the battery burns, what are the consequences?

A series of tests conducted by FAA last year showed that when an overheated Lithium battery will cause a chain reaction to nearby batteries, causing a short circuit and becoming too heat.

Within 10 minutes after overheating, the steam and smoke from the battery will emit and spread to the cockpit as well as the passenger compartment. If on a real flight, pilots and passengers will have to wear oxygen masks to avoid poisoning. Not only that, the heat escape also makes the battery emit flammable gas inside the luggage compartments. A series of tests showed that this amount of gas was enough to blow away the baggage door and damage the aircraft.

The most recent test was conducted last month at the FAA technical center in Atlantic City, New Jersey. This test confirmed the results of previous tests, showing that the batteries are capable of emitting explosive gas. The chemical reactions inside the battery create a mixture of gases, but the largest of them is Hydro. The temperature of the fire can be up to 1100 degrees.

This is why the battery is burnt

Part of the reason comes from the general structure of energy batteries, specifically here, a cell Lithium-ion battery is made up of many sheets that carry opposite charges stacked on top of each other and separated by layers insulation.

But because 2 opposite electrodes are only separated by a thin insulating plate, so in special cases, these plates are broken and the charge is directed through the opposite plates, the whole battery will heat up. fast and fire.

The Economist once had an article explaining this phenomenon of Lithium batteries. The advantage of a Lithium-Ion battery is that it has a higher energy density than other batteries, meaning that when the same volume is available, the Lithium battery will yield greater energy. The advantage is that batteries use electrolytes filled with Lithium salts, which are used to supply electrons to electrodes. However, problems with Lithium batteries will arise if there is an error or damage on the ultra-thin partition between the battery components. This will cause a short circuit in the battery and lead to overheating, which can cause the battery to burn . According to Airbus engineer Paul Rohrbach, the aircraft can still operate normally if only a few small flames come from the batteries , but with a large number of batteries in the luggage compartment, The fire can destroy aircraft.

However, this regulation also causes many difficulties and troubles for airlines and passengers traveling on airplanes. As of now, passenger flights have not recorded any cases of burnt luggage when carrying Lithium batteries. But when major airlines impose this ban as a flight safety standard, smaller airlines will be under pressure to follow these standards.