F21 heavyweight torpedoes by French naval defense company DCNS are being powered by silver oxide-aluminum electro-chemical battery stacks from Saft.

The silver oxide-aluminum electro-chemical, or AgO-Al, seawater-activated stack delivers the high power needed to propel the torpedo at a top speed of more than 56 miles per hour over a distance of more than 31 miles, Saft said.

It delivers twice as much energy and power as conventional silver-zinc batteries for the same mass and volume.

The F21, which weighs 1.6 tons, is the French Navy's newest torpedo for use against submarines and surface vessels. It uses fiber-optic wire guidance and wake/acoustic homing.

In addition to propelling the weapon, Saft's product will power the torpedo's onboard electronic control and guidance systems.

"This latest contract to supply electro-chemical stacks for the F21 torpedo is further consolidation of Saft's near-30-year relationship with DCNS and cements Saft as the world leader in electric propulsion batteries for heavyweight and lightweight torpedoes," said Serge Fouilhaux, director of Saft's Space & Defense Specialty Battery Group. "Silver oxide-aluminum electro-chemical stacks are unique to Saft and offer unrivalled performance, reliability and safety for torpedo applications."