Japan has a strong history of building amazing non-nuclear attack submarines. The Taigei-class should be a warrior below the waves, and make China very nervous – Thanks to advanced lithium-ion batteries, the Taigei-class of conventionally-powered submarines can remain submerged for much longer than other non-nuclear subs.

Taigei-class, the History
The Japan Maritime Self-Defense Force, or JMSDF, recently launched the second of a new class of diesel-electric submarines, the Taigei-class from a Kawasaki Heavy Industries shipyard in Kobe The latest submarine, christened Hakugei, or White Whale is one of Japan’s most advanced, thanks to a novel battery system.
New Batteries Make the Taigei-class Special

The Taigei-class is a conventionally powered diesel-electric class, but unlike other similarly powered submarines, the Taigeis can stay submerged for much more extended periods of time. The secret? Batteries. The Taigei-class is equipped with a high number of lithium-ion batteries that store electrical energy created by diesel generators. Unlike the traditional lead-acid batteries that power most submarines, the new lithium-ion batteries can store more energy, allowing for greater speed and endurance underwater. The Japan Maritime Self-Defense Force began researching lithium-ion technology in the early 2000s; the batteries are also thought to be less maintenance-intensive than traditional batteries.

The attack submarines are equipped with six torpedo tubes and can also launch Harpoon anti-ship missiles. And while the class is not much bigger than preceding Japanese submarines, they’re the JMSDF’s largest submarines to date, at around 3,000 tons. They’re also likely Japan’s quietest submarines. Thanks to extensive research into reducing fluid noise, or the sound generated by water passing around the sub’s hull, and propulsion sound damping, the Taigeis are thought to be extremely quiet. Ultimately the Japan Maritime Self-Defense Force would like to acquire seven Taigei-class submarines.

An Eye on China
The Japan Maritime Self-Defense Force submarine fleet increase is very much in line with other Japanese defense developments. However, although the Japanese military is constitutionally bound to be a defensive force only, recent a recent flurry of capability expansion has caused some domestic consternation.

Most recently, the Japan Maritime Self-Defense Force’s Izumo-class multi-purpose destroyers have been retrofitted to facilitate F-35Bs, the short takeoff and vertical landing variant of the American-built Joint Strike Fighter. In order to not call the destroyers aircraft carriers, JMSDF has dubbed the class helicopter carriers, though they are functionally small aircraft carriers.
Taigei-class – What’s Next?

Though not the largest submarines in Asia, the Taigei-class represents a new class of small but very capable submarines that could arguably be among the most difficult to detect in the region. And with an eye on an increasingly belligerent China, the JMSDF is becoming more capable both above and below the waves.