Famous Alvin Sub Waits for Lithium-Ion Battery Pack

By · May 28, 2013

Alvin on deck

Alvin on the deck of the research vessel WHOI R/V Atlantis in Woods Hole. A trip to the west coast, and another three years of scientific exploration, is imminent. (Jim Motavalli photo)

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.

Back in Action

Alvin's robot arms

Alvin hydraulic robotic arms pick specimens off the ocean floor. (Jim Motavalli photo)

Alvin was sitting in its custom-made “garage” on the Woods Hole, Massachusetts-based WHOI R/V Atlantis research vessel last week, shortly before a trip to the West Coast and its first exploratory dives this summer. Scientific research will start up again in the fall if everything goes well.

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.” Here's a closer look at the Alvin on video:

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.”

How It Could Work

The battery issues the WHOI engineers are grappling with are essentially the same safety concerns that automakers have faced and overcome in going electric. Gomez-Ibanez identifies four key priorities:

  • The batteries will be partitioned so a small, localized fire won’t spread to adjacent cells. “If one neighborhood burns you don’t want it to engulf the whole city,” Gomez-Ibanez said.
  • Cells will have to be assembled under extremely clean conditions, with strict controls on all the manufacturing steps. “It’s difficult, because usually the cells aren’t made just for you,” Gomez-Ibanez said. “They’re usually made in large quantities by someone else.”
  • In operation, cells have to be closely monitored so temperature and other variables remain within safe limits.
  • Positioning is vitally important. “You can’t put anything extremely life-critical next to the batteries,” Gomez-Ibanez said. “No proximity to any systems that could compromise the structure or floatation.”

With li-ion, Alvin should be able to explore whole new realms of the deep ocean floor. With lead-acid, it will be business as usual. By the way, Gomez-Ibanez may be convinced of the benefits of li-ion, but he's no big fan of the electric car. "I don't have one, and I don't see the benefits at this point," he said. "They're too expensive and complex. I ride a bicycle."

Comments

· · 4 years ago

While I enjoyed looking at the 1964 Alvin, the rest of the article's premise is pretty silly, and I'm sure everyone realizes it. How many Lith Ion battery powered cars have been sold and how many of them have burst into flames? How many non-sony laptop computers have burned down board room wood desks lately? So the issue is THAT silly. Compared to the value of the rest of the ship, an 80 kwh battery seems like a less than trivial matter. Its that silly an issue. The 1964 designers supposedly understood how to fuse lead-acid battery distribution. If any are still around I would bet they'd say use the identical fusing for the next battery system.

(The Fiskers caught fire due to no fuse in the electric radiator fan circuit. It would be the same issue with any other gasoline powered car. A penny in the fuse box issue, for those who remember what a edison base fuse box looks like).

· · 4 years ago

And, while we're talking about Alvin, Jim and Bill, let's not forget Simon, Theodore and Dave Seville . . .

http://www.youtube.com/watch?v=O9ya9yUHdrM

Seriously, though, I bet those old lead acid batteries were a lot of "fun" when they would invariably vent inside that sealed submarine.

Also . . . rather odd that Daniel Gomez-Ibanez dismisses EVs as "too complex." Nice that he rides a bicycle (so do I,) but - unless one is factoring non-essential gadgetry - any EV is going to be mechanically simpler than a comparable model ICE car.

· · 4 years ago

Ben... Now the song is in my head. ;)

There are safer chemistries of Li than what Boeing used. Obviously, they (WHOI/Navy) want to pick what suits their needs best. Although, packing and thermal management can solve that also.

· · 4 years ago

I couldn't help thinking that the weight of the battery pack is not a big issue when you're in water (or losing only 500 lbs from your 38,000 lb total weight). However, lithium could be stored in a smaller space (especially if they did a redesign) and the running time would be longer ... so these are definite advantages.

· · 4 years ago

Sorry, NN99, I can never resist a bad pun. One has to wonder, though, what motivated the naming of this sub back in 1964. Alvin and the Chipmunks, after all, were still fairly new cartoon characters.

If the submarine folks are looking for the safest lithium batteries, then Lithium Iron Phosphate (LiFePO4) would probably top the list. But, even here, as others have pointed out, a properly implemented system of fusing, charging/discharging regulation and thermal management are going to be the most important things to consider.

· · 4 years ago

To the fellow who suggested that lead acid batteries venting hydrogen into the crew sphere would be a problem; Of course the batteries are housed in their own separate pressure vessels called battery pods for precisely that reason, and the type of battery used is sealed AGM, not flooded, so they do not vent any gasses. Submersibles typically contain several independent pressure housings, the largest for the crew and a few others for things like liquid oxygen (as the life support system is basically one big closed loop rebreather) and those components which require dry, surface normal conditions to function, such as the batteries.

· · 4 years ago

Thanks, Zamboro, for the clarification. I assumed that there would be some sort of provision for sealing off batteries and other devices from the crew's breathing space on a vessel like this . . . although I remember reading about German WWII U-Boats as a kid and noting then that battery venting of gases on those comparatively primitive wartime machines was a problem for their crew.

For an interesting historical aside on the history of U-Boat batteries, I found this web page this morning . . .

http://www.uboat.net/technical/batteries.htm

Also . . . AGM batteries weren't available until 1972 (or so says the Wikipedia page on the subject,) so Alvin would have certainly spent at least its first 8 years - if not more - in service with flooded lead acid cells.

And . . . to put my chipmunk cartoon conspiracy theory to rest, I've since discovered that Alvin (the sub) was named for Allyn Vine, who's pioneering work in the field underwater oceanography was the inspiration for the project.

New to EVs? Start here

  1. Seven Things To Know About Buying a Plug-In Car
    A few simple tips before you visit the dealership.
  2. Incentives for Plug-in Hybrids and Electric Cars
    Take advantage of credits and rebates to reduce EV costs.
  3. Buying Your First Home EV Charger
    You'll want a home charger. Here's how to buy the right one.