We’ve all seen videos of electric cars, powered by lithium-ion batteries, burning furiously as thousands of gallons of foam are hosed on them. Any fire on a boat is scary enough, but the thought of one caused by a reaction called thermal runaway is terrifying.
The good news is that these fiery incidents are rare, and the benefits of this battery technology far outweigh any downside. The recently released E-13 Standard from the American Boat & Yacht Council could go a long way toward helping boatbuilders, insurers and other industry players feel more comfortable about vessels that incorporate this technology.
Types of Batteries
Most lithium-ion battery providers in the marine industry use lithium-iron-phosphate (LiFePO4 or LFP) chemistry. Its high flash point has proved safer, and these batteries are less expensive to produce than the more-efficient nickel- cobalt-aluminum (NCA) batteries often used by car companies such as Tesla.
MastervoltBut even the more volatile battery chemistries can be made safe with proper construction and safety protocols, as proven by Torqeedo, which uses NCA batteries sourced from BMW.
Although “dumb” lead-acid batteries are subject to many of the same issues facing lithium-ion batteries, the consequences of failure aren’t nearly as spectacular. The main causes of thermal runaway are overcharging, overdischarging, excessive external temperature, mechanical damage, external short circuit, and dendrite formation, which can pierce the barrier between the cathode and anode, causing an internal short circuit.
In addition, potential damage to engine components such as alternators led Yamaha Marine to include the following statement in its product information guide: “Lithium-ion batteries are not approved by Yamaha for use with Yamaha Marine products. Yamaha is currently evaluating a wide range of configurations and materials used to construct lithium-ion batteries, as well as the internal circuitries used to monitor, accept and distribute amperage/voltage. Until Yamaha’s evaluation is complete, Yamaha cannot approve the use of any lithium-ion batteries with Yamaha Marine products.”
Battleborn Cruiser AcademyE-13 Sets the Standard
Because of the potential problems that lithium-ion batteries can cause, the ABYC created the E-13 Standard, which was released last year in July. According to its scope, outlined in section 13.1.1, the standard addresses the selection and installation of lithium-ion batteries on boats, lithium-ion battery system design (house bank, cranking, propulsion) and manufacturer safety information.
The goal of the standard is to set a floor from a safety perspective by utilizing performance requirements without limiting the industry’s innovation.
While the standard addresses many areas, perhaps its most important element is the requirement that all lithium-ion batteries have a battery management system that includes an automatic battery cutoff if hazardous conditions exist. In addition, all batteries shall also have a manual cutoff.
Another important section (13.8.1) specifies that the battery manufacturer shall provide comprehensive safety information regarding the owner-operator’s responsibility, and proper installation and maintenance of the batteries — something that’s often missing with cheap imports of dubious provenance.
With prices plummeting to less than $150 for a 12-volt, 100-amp-hour lithium-ion battery online, the potential for mishaps is growing.
Developing the Standard
According to one of the standard’s authors, Nigel Calder — who has been an active participant in the ABYC’s 31-member Electrical Project Technical Committee for more than 30 years — the lithium-ion standard has been a work in progress since 2013. To gain further insight from manufacturers, a subcommittee was created in 2014 that included representatives such as Menno Ligterink from Mastervolt, Jochen Czabke from Torqeedo and Denis Phares from Dragonfly Energy.
“In the early years, we struggled with issues like whether or not to write what essentially amounted to construction requirements for home-built batteries, whether LFP should be treated differently to other chemistries, and should there be third-party testing by recognized labs to recognized standards, which would eliminate all the home-built batteries and many of the so-called drop-in batteries,” Calder says.
ABYC technical director Brian Goodwin, who is responsible for managing the review and publication of more than 70 standards, says E-13 was first published as a technical information report (TE-13) in 2020. Those reports are informative documents that do not contain requirements. Once the subcommittee had a draft, it was reviewed by the Electrical Project Technical Committee through the typical standards review process.
“As the tech info report was written with the idea that it was going to evolve into a standard,” Goodwin says, “the first step was to change all the ‘shoulds’ to ‘shalls.’ This draft was reviewed and then proceeded through our ANSI-accredited standards review process.”
E-13’s Effect
According to Phares, the E-13 Standard will be a benefit to insurance companies and those they insure. “ABYC is an incredibly respected organization in the industry, and one that many insurance companies recognize. Before the E-13 Standard, there were no recommendations for insurance companies to turn to. I think that will make a significant difference when determining policies for marine vessels with lithium batteries on board.”
According to Scott Stusek, a broker for the Gowrie Group insurance company, “A few years ago, our underwriter, Markel, wouldn’t allow us to insure anything with lithium ion batteries, but thanks to our conversations with ABYC, things have recently loosened up and we have been able to insure vessels with a valuation under $500,000 that use LiFePO4 batteries that are professionally installed along with a few other stipulations. Because of the E13 Standard we should be able to insure even more people in the future.”
“The ABYC E-13 standard provides useful guidance, taken together with standard ABYC E-11 prescriptions,” Calder says. “I believe it will greatly help people have reliable and safe lithium-ion installations.”
Because the E-13 Standard is new, it will be revised in three years (2025) instead of the usual five years for existing standards. Calder characterizes E-13 as a good start but says he believes it’s still a somewhat weak standard because third-party testing is only advised, not required. He expects future revisions to contain this amendment.
Phares also expects the standard to be expanded. “I do think it is comprehensive, but not stringent enough,” he says. “The defined standards had to be comprehensive but less stringent than I believe they will end up becoming in the long run. I believe there will certainly be third-party listing requirements for lithium-ion batteries that don’t currently exist.”
This article was originally published in the April 2023 issue.
