Battery systems that power some of the military’s key weapons systems are being updated with new technology as a result of Defense Logistics Agency partnerships with Army industrial sites and battery manufacturers.
Recent work led by DLA’s Battery Network research and development program includes the development of a new lithium ion-based power system for the TOW 2 anti-tank missile system and new lead-acid batteries used on armored vehicles such as the Bradley Fighting Vehicle.
The current “flooded” lead-acid batteries, in the 4HN and 2HN configurations, still require users to deal with the messy and potentially dangerous task of opening the cells and refilling them with acid. These batteries were commonly used in the ‘50s and ‘60s to keep cars running but have been replaced with safer, more powerful alternatives, said Matt Hutchens, an industrial engineer who leads the BATTNET Program.
“Industry got away from what’s called a liquid electrolyte and moved to a gel or glass-like material that’s solid. It actually lengthens the life of the battery and takes away the hazardous issues of dealing with acid. They also charge quicker, hold the charge longer and have fewer issues in terms of disposal,” he said.
The Army’s Tank-automotive and Armaments Command sought DLA’s input in 2017 on whether the 4HN and 2HN batteries could be replaced with ones made with new absorbent glass material.
“Part of the problem was, we couldn’t find any of the big producers of lead-acid batteries that wanted to fool with these military-unique batteries that DLA buys only 1,000-2,000 of a year,” Hutchens said.
The Army’s interest renewed DLA’s search for such a manufacturer. Hutchens found a company that produces green lead-acid batteries and owns some of the original patents for a glass-like material that has become an industry standard. In February, DLA awarded the company a contract for a 12-month development project that will result in new 4HN and 2HN lead-acid batteries DLA can procure.
The two-phase, $680,000 project will begin with the production of 10 handmade prototypes that will be tested by TACOM. Once the design and prototypes are approved, the contractor will, using a standard manufacturing processs, provide 10 batteries built on its production line for TACOM qualification.
Other lead-acid batteries used in military tanks and vehicles, such as the 6T configuration, have already transitioned to new versions made with advanced technologies, Hutchens said. But the 4HN and 2HN configurations remain a challenge for contracting experts at DLA Land and Maritime.
“These older batteries have all sorts of restrictions in terms of shipping, transportation and storage because they’ve got this wet acid inside them. When you look at the procurement contracts there are lots of issues that have to be considered, so coming up with a new solution will simplify DLA’s procurement, distribution and disposition process,” Hutchens said.
The BATTNET Program is also behind major improvements in the battery used to power the TOW2 missile system. The current battery is comprised of a nickel cadmium assembly with a detached charging system that was designed in the 1970s. Nickel cadmium has become scarce, and electrical components in the charger have significant obsolescence issues, as well. The legacy equipment also failed to meet warfighters’ performance goals.
“The customer wasn’t happy with the number of missile firings they were getting. Ideally, they wanted to get over 90 missile firings, either live or simulated, in one charge. They weren’t getting anywhere near that, and it takes time to recharge the batteries,” Hutchens said.
DLA partnered with the Army Aviation and Missile Command and a design team starting in October 2016, and after more than a year of tests and design improvements, a new lithium-ion based power system is expected to be in production this year. The new system has several benefits, including a reduction in weight by about 120 pounds and potential procurement savings of $8 million a year for the customer.
“One of the things we were able to do was consolidate all the electronics that you need for charging management into the existing battery format. So the old charger went away, the power conditioner went away, and the battery for the night vision sight went away,” he added.
The customer wanted to maintain the battery box’s size so it could slide into the current guidance system and recognized during the project’s initial stages that the box was large enough to hold two BB-2590 lithium-ion batteries. Two BB-2590s could meet all the power requirements of the missile guidance system and the night vision sight.
“The BB-2590 is a standard-issue battery that’s already qualified and used in a lot of different systems run by the Army and Marine Corps. It’s one of our major logistics items, and DLA has multiple qualified suppliers,” Hutchens said. “The new design can also use two BA-5590 non-rechargeable batteries if necessary.”
DLA’s BATTNET program was created in 2010 to bring address sustainment problems, improve manufacturing capabilities, and bring new manufacturing technologies to DLA’s supply chain. As such, Hutchens is also working with industry to promote facility and production line changes like the installation of automated welding and assembly lines for critical DLA batteries.
Other work involves the use of laser cutting at low energy levels for battery electrodes. “While laser cutting is an established technology for many products, it’s been challenging to apply to battery electrodes because they’re essentially coated aluminum foil,” Hutchens explained.
“We’re now in the second phase of a project where the company has the equipment and a lot of folks are coming to their door to talk to them about either buying cells based on their laser-cut electrodes or buying a version of their electrode cutter. I think it’s going to make a big improvement in the whole commercial and military battery industry,” he said.
Investing time and funds in research and development of batteries helps the agency provide better products to customers and benefits the services, which usually put their money toward new equipment rather than solving sustainment problems.
“DLA R&D doesn’t design a new weapon system or its components,” Hutchens added. “We’re just looking at existing components and saying, ‘What kind of problems are we seeing? And are there some things we could work with the services to solve?’ That frees up their money for more critical needs.”