Lithium batteries, UL1973 and marine insurance

[OsodelMar]

Has anyone encountered problems with their marine insurance (e.g. denials) and lithium battery systems, specifically around issues with LiFeP04 batteries being or not-being Ul1973 certified? I've seen some older posts on this forum but don't see anything recent. I'm about to make a LiFePO4 upgrade, and debating whether or not I should go with UL1973 certified batteries, which would be significantly more expensive.

[tanglewood]

Originally Posted by OsodelMar

Has anyone encountered problems with their marine insurance (e.g. denials) and lithium battery systems, specifically around issues with LiFeP04 batteries being or not-being Ul1973 certified? I've seen some older posts on this forum but don't see anything recent. I'm about to make a LiFePO4 upgrade, and debating whether or not I should go with UL1973 certified batteries, which would be significantly more expensive.

It's unclear to me exactly what a "UL1973 certified battery" actually is. UL 1973 is a standard for light rail and standby power systems, so you are talking about really big stuff, and a standard that goes well beyond a battery as we know them in boats. My guess is that vendors advertising such batteries have picked various aspects of 1973 that they think are applicable to a stand along battery pack, but what parts? Who knows?

[CarlF]

I think the testing of LiFePO4 batteries by ABYC where they couldn’t get them to catch fire has made the insurance companies somewhat more relaxed.

But be prepared to provide the name of the certified electrician who installs them. They are very wary of owner installations.

[OsodelMar]

Tanglewood, I am not completely up-to-speed on UL1973, but from what I understand after a little bit of research is that they have an aluminum case that inhibits or suppresses fires. One of the popular marine LiFePo4 batteries, Lithionix, is UL1973 certified and goes for quite a bit more than comparable non-UL1973 batteries. Other batteries (like the Napa house-brand Expio360) seem to be headed in this direction. Victron (high-quality LiFePO4 batteries) is about to release a UL1973 version, their NG series.

[OsodelMar]

Thanks, CarlF. I consider myself a competent do-it-yourselfer, but your note about 'certified electrician' is good. Problem for me is, my boat is in the Sea of Cortez. Maybe a fellow cruiser who is ABYC certified is my answer.

[Indolent58]

Originally Posted by OsodelMar

Thanks, CarlF. I consider myself a competent do-it-yourselfer, but your note about 'certified electrician' is good. Problem for me is, my boat is in the Sea of Cortez. Maybe a fellow cruiser who is ABYC certified is my answer.

The prior owner of my boat always used ABYC electricians and the wiring was a horror show when we bought it. I’m still finding things done wrong. That doesn’t mean that insurance companies don’t want what they want, but I trust myself over many professionals if only because I care more and have more time.

[CarlF]

Originally Posted by OsodelMar

Thanks, CarlF. I consider myself a competent do-it-yourselfer, but your note about 'certified electrician' is good. Problem for me is, my boat is in the Sea of Cortez. Maybe a fellow cruiser who is ABYC certified is my answer.

My insurance company didn't even say "ABYC" but that may be because the box on the form was too small. In any case, I think a cruiser with some professional electrical experience helping out would meet the test. Get an invoice for your files.

As far as I know, UL1973 is not required in the ABYC E-13 Lithium battery standard. I think that makes it unlikely to be required by insurance companies or surveyors. Most of E-13 is basic battery stuff like having the batteries well secured. Be sure to have a shutoff and a Class T fuse. The only difficult one is an alarm before the BMS disconnects but this seems to be ingored - maybe because the possible damage is usually limited to blowing the alterntaor diodes - not something insurance companies worry about. And there are several easy ways to prevent this without communication from the BMS.

[wholybee]

Originally Posted by CarlF

My insurance company didn't even say "ABYC" but that may be because the box on the form was too small. In any case, I think a cruiser with some professional electrical experience helping out would meet the test. Get an invoice for your files.

As far as I know, UL1973 is not required in the ABYC E-13 Lithium battery standard. I think that makes it unlikely to be required by insurance companies or surveyors. Most of E-13 is basic battery stuff like having the batteries well secured. Be sure to have a shutoff and a Class T fuse. The only difficult one is an alarm before the BMS disconnects but this seems to be ingored - maybe because the possible damage is usually limited to blowing the alterntaor diodes - not something insurance companies worry about. And there are several easy ways to prevent this without communication from the BMS.

It does refer to UL1973, in 13.5.4. The PDF I have doesn't allow cut and paste and I don't want to type the whole thing, so you will have to find a copy. But it requires at least *one* of a whole list of standards, including UL1642, UL1973, and UL2054, as well as several IEC and SAE standards. But since it only requires one, I wouldn't get hung up specifically on UL1973. As long as it is approved for some use by some standards org, you are probably fine as far as ABYC is concerned.

E-13 does NOT require an alarm either. It is mentioned in a note as a recommendation, but an installation can be compliant without it. The bulk of the standard is just general information without much guidance, and the guidance that is there simply says to follow the manufactures instructions.

You also have to comply with E-10 and E-11 of course.

[tanglewood]

Originally Posted by wholybee

It does refer to UL1973, in 13.5.4. The PDF I have doesn't allow cut and paste and I don't want to type the whole thing, so you will have to find a copy. But it requires at least *one* of a whole list of standards, including UL1642, UL1973, and UL2054, as well as several IEC and SAE standards. But since it only requires one, I wouldn't get hung up specifically on UL1973. As long as it is approved for some use by some standards org, you are probably fine as far as ABYC is concerned.

E-13 does NOT require an alarm either. It is mentioned in a note as a recommendation, but an installation can be compliant without it. The bulk of the standard is just general information without much guidance, and the guidance that is there simply says to follow the manufactures instructions.

You also have to comply with E-10 and E-11 of course.

All the above is correct.

In my opinion, UL1642 (and its IOS companion) is the important baseline. When you think about the dangers of lithium ion batteries vs lead batteries, the concern is that under some fault condition the cells go super-nova. That's where UL 1642 comes in. It's a battery cell standard that subjects the cells to a wide range of highly abusive and destructive tests to ensure they do NOT go super-nova. The cells are massively overcharged, over heated, crushed, punctured, shaken, and direct shorted. To pass they cannot catch fire, explore, or spew hazardous material.

Given this, if you have a battery made up of cells that pass UL 1642, then you have a battery that is no more dangerous than a conventional LA batteries. In fact it's arguably less dangerous because it won't spew explosive gas, it won't spew corrosive sulfuric acid, and it doesn't contain toxic lead.

[Pete7]

Originally Posted by tanglewood

In fact it's arguably less dangerous because it won't spew explosive gas, it won't spew corrosive sulfuric acid, and it doesn't contain toxic lead.

Plus it has a BMS to isolate the LFP in the event a number set parameters are exceeded, unlike lead acid.

Pete

[wrwakefield]

Originally Posted by OsodelMar

Has anyone encountered problems with their marine insurance (e.g. denials) and lithium battery systems, specifically around issues with LiFeP04 batteries being or not-being Ul1973 certified? I've seen some older posts on this forum but don't see anything recent. I'm about to make a LiFePO4 upgrade, and debating whether or not I should go with UL1973 certified batteries, which would be significantly more expensive.

In Nov-2023 I asked our marine insurance broker [AMIG covers our vessel] whether there were any considerations if we upgraded our house battery bank with ‘name brand’ [i.e., not homemade] LFP batteries.

Their response:

AMIG does not have any specifications/guidelines/exclusions regarding battery type. As long as whatever battery you have or you get is installed to meet fire/safety guidelines for that variety, then you are fine with any kind.

I hear anecdotally in forums that this may not always be the case.

I am in final planning stages and will inform my broker agent [and hence the underwriters] of the details when the transition is complete.

FWIW

Cheers, Bill

[sailorboy1]

Originally Posted by CarlF

But be prepared to provide the name of the certified electrician who installs them. They are very wary of owner installations.

who is this they?

[CarlF]

Originally Posted by sailorboy1

who is this they?

"They" are insurance companies. But it isn't uniform. I've had two directly state that they will not insure boats with owner installed lithium batteries. But I've had others not raise the issue.

[CarlF]

Originally Posted by tanglewood

All the above is correct.

In my opinion, UL1642 (and its IOS companion) is the important baseline. When you think about the dangers of lithium ion batteries vs lead batteries, the concern is that under some fault condition the cells go super-nova.

LiFePO4 batteries simply will not go "super nova" (if by that you mean "catch fire"). Here is a letter from the ABYC president on their attempts to do just that:

"ABYC is built on a tradition of common sense and real world experiences. Early in my technical days, I was told ABYC designed the Standards so the backyard boatbuilder could achieve desired results. Testing and methodology were crafted in plain language for a “common sense” approach to a safe product.

We did not set aside best engineering practices for simplicity; the technical committee is packed with engineers and data-crunchers overseeing the process of drafting and updating the Standards. This balance has helped ABYC create useable, reliable, and relevant documents that help to achieve an unmatched level of safety in our industry. This is why, when the US Coast Guard asked us to look into potential problems with Lithium Iron Phosphate (LiFePO 4) batteries on boats, we jumped at the chance.

The ABYC Technical Department, with input from the industry, recreated a number of scenarios based on accident narratives that claimed LiFePO 4 batteries to be the cause of a fire. In our on-site test lab, our team subjected batteries to conditions ranging from “normal” operations to extreme use and abuse. We purchased units built for the marine environment with robust battery management systems. We also included recycled batteries available from mass retailers, with an “optional” battery management system and no clear instructions from the battery or cell manufacturer. We tried to replicate sketchy behavior which is the fear of insurance companies and regulators alike.

Do you know what we found? We couldn’t start the fire (Sorry Billy Joel). We witnessed swollen cells, completely dead batteries, and multiple safety cutoffs (when not bypassed). We had a very hot summer here in MD. Even the high heat didn’t come close to a spontaneous combustion scenario.

We arranged calls with industry experts, and we asked them what we might be missing in our testing. What can we throw at these batteries to replicate the accidents we were hearing about? No one had anything to add, short of putting these batteries directly in a fire (which we did). We were able to add LiFePO 4 batteries to a local International Association of Arson Investigators (IAAI) boat burn--even there, no one detected any indication that the batteries themselves contributed to the fire. Many of us were fully expecting a report where we were able to replicate an unsafe situation and make some recommendations.

Our full report will be sent to the USCG in due course, and then ABYC will report on our findings."

[sailorboy1]

Originally Posted by CarlF

"They" are insurance companies. But it isn't uniform. I've had two directly state that they will not insure boats with owner installed lithium batteries. But I've had others not raise the issue.

So who are "they"? "They" must have names.