Japan's new subs could use the same batteries as your cell phone

Imagine your cell phone battery – on an immense scale. That will be what helps power the next generation of Japanese submarines.

According to a report by TheDrive.com, Japan has chosen to use lithium-ion batteries for the follow-on to its Soryu-class submarines. The Soryu-class vessels are considered to be among the best diesel-electric boats in the world, with six 21-inch torpedo tubes and the ability to hold up to 30 torpedoes or UGM-84 Harpoon anti-ship missiles, according to the “16th Edition of Combat Fleets of the World.”

Japan Maritime Self Defense Force (JMSDF) submarine Hakuryu (SS-503) arrives at Joint Base Pearl Harbor-Hickam for a scheduled port visit, Feb. 6. While in port, the submarine crew will conduct various training evolutions and have the opportunity to enjoy the sights and culture of Hawaii. (U.S. Navy photo by Cmdr. Christy Hagen)

For all the considerable capabilities of the Soryu-class vessels, they — like all diesel-electric submarines — have long faced a problem: While they are very silent when running off batteries, eventually the batteries run out – just like anyone with a portable electronic device has found out to their chagrin at one time or another.

To avoid being stuck somewhere bad, they use diesel engines to recharge the batteries. But the submarine either must surface (and become visible and vulnerable), or use what is called a “snorkel” at periscope depth. The snorkel is not much better – diesel engines are noisy, and making noise is a good way for a submarine to be located and killed.

The Soryu-class submarines use the Stirling diesel engine – a form of air-independent propulsion. The problem is that this is a bulky system and takes up space. They also have to take the oxygen down in the form of liquid oxygen.

Japan Maritime Self-Defense Force (JMSDF) submarine Hakuryu (SS-503) visits Guam for a scheduled port visit. Hakuryu will conduct various training evolutions and liberty while in port. (U.S. Navy photo by Mass Communication Specialist 1st Class Jeffrey Jay Price)

TheDrive.com notes that the use of lithium batteries and diesel engines in a conventional layout (replacing the traditional lead-acid batteries) would provide many of the same endurance advantages as the air-independent propulsion, but in a much more compact package.

This means the submarine can go longer between charges – which won’t take as long, either. There will be tactical advantages, too, like allowing the sub to go faster underwater.

One disadvantage of using the lithium-ion batteries has to be kept in mind. Just ask the owners of certain Samsung products. A compilation of the more… spectacular failures is in this video below.

Still, when one considers the space savings that will come from using giant cell phone batteries in a conventional plant, adding fire-suppression technology might not be too hard. That challenge will be a small price to pay when compared to what the new batteries will give.