Alvin - the submarine that found the Titannic - will be 50 years old next year. They are installing lithium-ion batteries that will give it even more range. It will be able to explore 98% of the ocean bottom then.
Harry - When I taught oceanography many of my lessons included information collected by Alvin.
From PlugIn Cars Magazine -
No, it doesn't look much like an electric car, but there are some remarkable parallels. The famous deep-sea submarine Alvin, which explored deep-sea vents and the wreck of the Titanic, has made 4,600 dives and remains a state-of-the-art submersible despite its 1964 construction date. Alvin, owned by the Navy and operated by the Woods Hole Oceanographic Institute (WHOI), has just undergone a $41 million upgrade that will allow it to reach 6,500 meters and explore 98 percent of the ocean’s floor.
Alvin has the latest technology in every area but one—its battery pack. Like a 1909 Detroit Electric, Alvin is powered by lead-acid batteries. Those batteries, which weigh 3,500 pounds, power everything from the reversible thrusters that the Alvin uses to navigate to the exterior lights.
According to Susan Humphris, a WHOI senior scientist who headed the Alvin’s renovation, “To go to 6,500 meters, we’re going to need a new battery system. We’re looking at lithium-ion, but since the Boeing Dreamliner issue came up we’ve been pursuing more research to ensure that we can package those cells in a safe way.”
Of course, many of these same safety challenges apply to Boeing’s planes. Li-ion batteries are inescapable, because of their energy density and lower weight, but volatility remains a serious issue, especially in critical applications such as Alvin.
Replacing the battery pack is a high priority as part of Phase II of the submarine’s upgrade. According to Humphris, “We’re hoping we’ll be able to upgrade the pack within five years. It remains a big question.”
Big Advantages to Lithium
Yes, the same flammability issue that grounded the Dreamliners is holding up deep-sea diving in the Alvin. But li-ion has so many advantages (including a 500-pound weight cut) that the engineers are working overtime to come up with a safe solution. According to Daniel Gomez-Ibanez, a WHOI engineer, the plan is to double Alvin’s battery capacity, from 40 to 80 kilowatt-hours, with more than 10,000 individual cells.
Gomez-Ibanez is still waiting for the go signal to begin work on such a lithium-ion pack, but in the meantime he’s clear about how the batteries will have to perform.
“It’s a lot of energy in a small volume, and there’s the potential to release that energy in a short amount of time,” Gomez-Ibanez said. “Anyone who says the technology is fundamentally safe is being overly optimistic. But sending a submarine down 6,000 meters is not inherently safe, either. You have to accept some residual risk.”