ABYC Lithium-Ion standard compliance

[twistedtree]

Anyone hiring out an LFP retrofit should require that the installation be ABYC compliant, and anyone doing it themselves should ensure the same thing. The standard has been out since July and is a good baseline set of requirements that all installations should meet. It's also a good reference benchmark if questioned by your insurance company, which seems to be increasingly common.


E-13 is the standard for Lithium Ion batteries, and it draw on E-11 which is the general electrical standard. Anyone doing work themselves would be well advised to get these standards. It will be a small yet valuable part of your project cost.



Off the top of my head, here are some key requirements. Note that this is my interpretation, and not a representation by ABYC.


- All batteries and/or cells need to comply with at least one of a handful of UL and ISO standards. In practice this boils down to requiring that all cells must minimally meet UL 1642 or the ISO equivalent. These certifications ensure that cells don't explode, catch fire, or do other dangerous things when subject to electrical and mechanical abuse. It's a very important starting point for a safe system, and any reputable device should these requirements, but check.



- You MUST have a BMS. By now this seems obvious, but in the earlier pioneering days some people built without a BMS. The BMS can be "internal" as in drop-in batteries, or "external" where it monitors and controls a bank of batteries. It doesn't matter how you do it, as long as it meets the functional requirements of the standard.



- There must be a defined "safe operating envelope", or SOE for the batteries AND the cells. These are the limits of safe operation for voltage, temperature, current, etc., as defined by the battery and/or cell manufacturer. It's important to distinguish the SOE from normal operating parameters like charge and discharge limits. SOE parameters are the final safety limits that must never be exceeded. Normal operation full charge voltage, minimum discharge voltage, and operational temp limits all happen before their corresponding SOE. In a correctly operating system, the SOE limits should NEVER be reached.



- The primary requirement on the BMS is that it must completely disconnect the battery if any aspect of the SOE is exceeded. This should NEVER happen in a correctly operating system. It's a last step safety disconnect to prevent risk of the battery becoming dangerous.


- Charging sources and loads must be controlled to operate within the charge/discharge limits set by the battery/cell manufacturer. These are the operation limits for full charge, full discharge, etc as required to correctly operate the battery. How you accomplish this is up to the system designer. You can program the chargers to stay within bounds, you can use a BMS that tells the chargers when to stop and start, or you can do a combination or create something else. But you have to operate within bounds for the cells and batteries.


- E-11 (the general electrical standard) requires a battery disconnect switch of some sort so you can shut off a battery bank in an emergency. E-13 makes it clear that this is still required for a lithium ion battery bank, and more importantly that the BMS disconnect device is NOT a substitute for the required disconnect switch. The BMS disconnect is in addition to the manual disconnect switch.


- The batteries need to be installed and secured per mfg requirements, be installed in a location that will respect temp limits, be dry, have requisite fire protection, etc.


- There are manufacturer documentation requirements for minimum info in manuals, etc.



There are also a number cautions and recommendations that are not mandatory, but that will be included in any best-practice installation. I think these recommendations also serve as a heads-up on things that might become mandatory over time.



- Make sure that the rest of your boat's electrical system won't be damaged if a BMS disconnect occurs. This mostly applies to alternators that can suffer damage if disconnected under heavy load. There are lots of ways to deal with this, and a good installation will do so.


- Advance warnings of an impending BMS disconnect is very desirable to give an operator an opportunity to intervene, if possible. Again, a disconnect should never happen under normal operation, so if one is impending, something has gone wrong and should be addressed.



- Critical boat systems should have alternate power sources so they can remain operational in the event of a BMS disconnect. Loss of DC power can have wide ranging impact on a boat, and this needs to be considered in the power system design.


I hope this helps anyone considering an LFP upgrade.

 

[BCRyan]

Great post and thank you for sharing. I read through your information carefully and I agree that it all seems like good common sense for either LI or LFP installations. I just could not be any happier with my LFP upgrade for house batteries.

 

[tpbrady]

TT,

The last paragraph on backup power for critical systems raises some questions about how to do it. Short of fuses blowing a lead acid bank won’t disconnect. With LFP, a disconnect could occur if the BMS fails. Today if I had an LFP house bank, my only backup would be to start the generator to use the charger inverter to provide DC power. With the main running, the redesign of the charging system to accommodate the LFP bank would have to take into account a disconnect of the BMS, but still provide DC power to critical systems. It doesn’t sound like a simple problem to solve.

Tom

 

[guy with a boat]

Thanks for posting the overview, Peter. This is great info for anyone considering LFPs.

We did our retrofit last year and the LFPs are a major upgrade. I don’t think it will be more than a handful of years before the debate goes away and LFP is the accepted best choice for house batteries. Establishing some guidelines is an important step in that process.

The ABYC standards are a step down that road. It seems likely that the standards will evolve but E-13 looks like a good foundation.

Thanks to you and the other contributors for making it happen.

 

[GMS]

Thanks for the summary of the ABYC standard, that is very helpful. Thankfully our DIY system mostly complies with the standard, as we implemented the REC BMS that has full control of our charge and discharge sources via CAN bus and will discount the bank if necessary.

The one area where our system would likely not be fully compliant is on the LFP cells themselves, as we did this a few years ago and I have no documentation that the cells are compliant with any UL or ISO standards. I suspect they would pass one of the standards as they are CALB LFP cells, but I cannot prove compliance.

I have not been in the market for new cells recently, but am very curious if anyone is aware of a source of raw LFP cells that are compliant with the recommended UL or ISO standard.

While I am not excited about switching out the cells in our house bank for different ones, it would be nice to know whether it is possible to obtain UL or ISO compliant raw cells.

Note, I have had multiple conversations with our insurer, and they currently do not have any requirements or prohibitions on types of house bank. However, we are monitoring that situation closely, as it would be a very expensive house bank if it invalidates insurance coverage

 

[twistedtree]

TT,

The last paragraph on backup power for critical systems raises some questions about how to do it. Short of fuses blowing a lead acid bank won’t disconnect. With LFP, a disconnect could occur if the BMS fails.

Well stated, and precisely the reason for the recommendation. We take for granted that DC power will always be there, even as the ship is starting to go down. It's the power source that most people use for critical systems.


Now with L-I, this can happen sooner than it might with lead batteries. Still, it should never happen in normal operation. If it does, something else is wrong with the system. But nonetheless, it's more likely than with lead.

Today if I had an LFP house bank, my only backup would be to start the generator to use the charger inverter to provide DC power.

Keep in mind that this might not work without a functioning battery of some sort. All the inverters I'm aware of won't even start if there isn't a battery connected. Dedicated chargers may be different. Whatever you backup is, you should test it to be sure it works as expected.

With the main running, the redesign of the charging system to accommodate the LFP bank would have to take into account a disconnect of the BMS, but still provide DC power to critical systems. It doesn’t sound like a simple problem to solve.

Tom

I think the ideal system is one with dual BMSes or some other paralleled battery system when if one fails, the other keeps going. This won't protect against all faults, but it will take a big chunk out of the problem. However this is probably to most complicated and expensive approach.


A simpler yet very effective alternative is to have a battery switch that lets you parallel in a start battery bank. It would be a manual operation, but would get you back online pretty quickly. I have even seen these built with a remotely controlled contactor that parallels in the lead bank with the push of a button at the helm. I have a simple 1-Off-2 battery switch that let's me parallel in either of two separate start banks. With the turn of a switch you are back to old-school power. It also provides an easy way to maintain DC power when working on the LFP system, upgrading firmware, etc.


BTW, another thing that E-13 recommends against is having different battery chemistries in the same bank. It's been a common practice to permanently parallel in a lead battery as a simple and cheap way to handle any BMS disconnect spikes from alternators. ABYC recommends against doing that. ISO has a pre-standard technical report which is the per-cursor to their equivalent standard, and they too recommend against such a practice, but clarify that it's with respect to normal operation. This clarifies that it's OK as an emergency measure, and I think is a good addition.

 

[twistedtree]

The one area where our system would likely not be fully compliant is on the LFP cells themselves, as we did this a few years ago and I have no documentation that the cells are compliant with any UL or ISO standards. I suspect they would pass one of the standards as they are CALB LFP cells, but I cannot prove compliance.

I'm not sure which CALB cells you have, but I have the 180Ah cells in my home power system and they meet UL 1642. All the big name vendors do.

 

[DDW]

Once again it's too bad that the ABYC can't publish these standards.

Two questions:

There was talk about requiring a pre-disconnect warning of 7 seconds or something like it. Do I understand correctly that that is a recommendation, not a requirement?

Same issue on paralleling chemistries - is it prohibited or recommended against?

I am aware of the arguments for such things, but also the difficulty of implementing them in every case.

 

[twistedtree]

Once again it's too bad that the ABYC can't publish these standards.

I think you mean "free" rather than "published". They are published, but not free, just like most books and like all standards that I'm aware of except the IETF. UL, ABYC, ISO, ANSI, NEC, NMEA, NFPA, SAE are all paid publications. I like "free" just as much as the next guy, but something has to pay for the ABYC staff and operations, and I think it makes sense that it should be the people utilizing the standards.

Two questions:

There was talk about requiring a pre-disconnect warning of 7 seconds or something like it. Do I understand correctly that that is a recommendation, not a requirement?

Same issue on paralleling chemistries - is it prohibited or recommended against?

I am aware of the arguments for such things, but also the difficulty of implementing them in every case.

Correct, both are recommendations, not requirements. But I think both are likely to become mandatory at some point down the road.


One of the sensitivities in creating the standard was to not unduly invalidate existing implementations unless they have the potential to really be unsafe.

 

[DDW]

Yes, free. It is true that ubiquitous standards like the NEC , ANSI, ISO, and SAE are paid publications, but the information in them is readily accessible through free sources. A standard that is inaccessible is like a law that is constitutionally vague: how do I know if I comply, if I cannot see what it is? They should have a DYI or boat owner version of membership that is much cheaper, or perhaps a cheap one time access to specific sections of interest. Their memberships are geared towards people who are making money off of its use, not individual owners forced (by insurance) to comply with a requirement invisible to them. The one time purchase of the standard for $500 is ridiculous for a boat owner, as is the cheapest membership at $275/yr.

I'd assume they'd like to see boat owners comply, hiding the standard under an expensive rock is not the best route to accomplish that.

 

[GMS]

While I am sure ABYC would like individual boat owners to comply, they are an industry group focused on boat builders and marine service providers. ABYC is not geared toward individual boat owners, and probably should not be.

Considering we spent in the neighborhood of $10k installing our house bank and related equipment upgrades, $275 to $500 is not terribly unreasonable a price to ensure compliance. Especially when you consider what our upgrade would have cost if we paid an ABYC certified technician to do the work.

That said, during our research it was not hard to file sources of information that outlined the important considerations (which at the time were only draft or the beginnings of draft standards). Like most "standards" the ABYC standards can often be found at least paraphrased and/or summarized through various online sources.

Just my 2 cents...

 

[twistedtree]

Yes, free. It is true that ubiquitous standards like the NEC , ANSI, ISO, and SAE are paid publications, but the information in them is readily accessible through free sources. A standard that is inaccessible is like a law that is constitutionally vague: how do I know if I comply, if I cannot see what it is? They should have a DYI or boat owner version of membership that is much cheaper, or perhaps a cheap one time access to specific sections of interest. Their memberships are geared towards people who are making money off of its use, not individual owners forced (by insurance) to comply with a requirement invisible to them. The one time purchase of the standard for $500 is ridiculous for a boat owner, as is the cheapest membership at $275/yr.

I'd assume they'd like to see boat owners comply, hiding the standard under an expensive rock is not the best route to accomplish that.

I hear you. I pay the $275 each year so I can spend days of time and pay for flights, hotels, meals so I can help write some of the standards. You would think I'd get a complementary membership.... I just look at it as a donation to the cause..


But out of curiosity, what would you consider reasonable for an individual membership that gets you access (probably online only) to the standards? It does strike me as a gap in their offering. $100/year? $150/year? $200/year?

 

[Gdavid]

Access to the standards through your insurance would seem like a good compromise to me. The insurance companies could pay a corporate rate for membership, high enough to satisfy the council and receive permission to disseminate the guidance to customers, potentially with some sort of compliance incentive.

-edit: I am not implying this is a current policy, just a possible arrangement.

 

[DDW]

My gripe is that the ABYC primarily benefits insurance companies and secondarily boatbuilders or repair yards, as a legal shield (and/or intellectual excuse). One can argue that a boatowner is a tertiary beneficiary, if a boatbuilders certification could be relied upon AND the ABYC standards were both necessary and sufficient (all great leaps of faith in my opinion). Otherwise a DIY boat owner is burdened by them, not a beneficiary of them, asking for payment to shoulder this burden is insult upon injury, from one point of view.

I feel your pain, having served on standards committees myself. Generally a thankless task.

What would be reasonable? Usually, a DIY boat owner isn't interested in the whole tome, rather just the section being worked on in the moment. Online access to a section costs the organization essentially nothing. I'd pay a small fee (like $10 - $15) to access say their propane section one time or for one week. It could be done by having to create an account with a payment method, and that would allow limiting to a few sections a year to prevent abuse. An ongoing $100/yr I'd find onerous. That is what they are getting from their certified technicians, many/most of whom are eking out a full time living from it. For a DIY, it is much more often a one time, one subject problem.

An example might be what Ford does for their vehicles, you can access the factory service documentation (for my truck 3000+ pages) for a limited time (I think 72 hours?) for something like $25.

Maybe we just need Ed Snowden to start WikiLeaks/ABYC from his new home in Russia .

 

[twistedtree]

My gripe is that the ABYC primarily benefits insurance companies and secondarily boatbuilders or repair yards, as a legal shield (and/or intellectual excuse). One can argue that a boatowner is a tertiary beneficiary, if a boatbuilders certification could be relied upon AND the ABYC standards were both necessary and sufficient (all great leaps of faith in my opinion). Otherwise a DIY boat owner is burdened by them, not a beneficiary of them, asking for payment to shoulder this burden is insult upon injury, from one point of view.

Well, I very much disagree with this assessment. I think boat owners are the primary beneficiary. That's certainly the focus of all the working discussions. Builders and equipment manufacturers are taken into consideration, but by no stretch of the imagination are they the focus.


If anything, ABYC is a burden on builders, equipment vendors, and technicians. Without it, they would just do whatever is easiest and cheapest for them. What's OK or not OK becomes a matter of opinion with no objective benchmark.

 

[Simi 60]

.

Maybe we just need Ed Snowden to start WikiLeaks/ABYC from his new home in Russia .

Julian Assange thanks
And unfortunately in his new home in prison trying to fight off US extradition.

And yes, my way of thinking is anything public safety orientated should be free access
Especially if the powers that be expect us to do it.

 

[DDW]

I would say ignorant or inexperienced boat owners are a beneficiary. Perhaps that covers the great majority. The 'objective standard' is the security blanket for the insurance companies and to a great extent the builders. I can show you many examples in my ABYC compliant boat which are simply not right despite compliance. Rules are often a replacement for knowledge and thought, and usually not the best replacement, but knowledge and thought are rarer than rules. If you are saying absent rules (and knowledge and thought) boats would generally be the worse for it, I would reluctantly agree.

 

[Airstream345]

Peter - nice summary and I really appreciate your additional recomendations at the end. I've often thought about adding a UPS to the 12V panel in the helm for this very reason

 

[bowball]

TT,

The last paragraph on backup power for critical systems raises some questions about how to do it. Short of fuses blowing a lead acid bank won’t disconnect. With LFP, a disconnect could occur if the BMS fails. Today if I had an LFP house bank, my only backup would be to start the generator to use the charger inverter to provide DC power. With the main running, the redesign of the charging system to accommodate the LFP bank would have to take into account a disconnect of the BMS, but still provide DC power to critical systems. It doesn’t sound like a simple problem to solve.

Tom

Or get batteries like mastervolt that have individual bms built in to each battery.

 

[teknoid]

The one time purchase of the standard for $500 is ridiculous for a boat owner, as is the cheapest membership at $275/yr.

Unless I’m missing something, it looks like $190/yr is an option

https://abycinc.org/mpage/becomeamember

 

[twistedtree]

Unless I’m missing something, it looks like $190/yr is an option

https://abycinc.org/mpage/becomeamember

Good find. I didn't know about that. It's step in the right direction.

 

[fgarriso]

Great post and Thank You for sharing.

 

[CharlieO.]

It also shows a free five-day trial. I'll wait until I'm ready to upgrade my electrical systems then option the free trial, then I'll be able to determine if it is a worthwhile investment for me.

 

[sunchaser]

Great thread TT. Post #1 is a nice summary. Question; do the SOE and suggestions adequately cover system behavior and design for winter lay ups of below freezing conditions other than "keep them warm"?

Having known and used several marine techs who are ABYC trained, there remains uncertainty as to best LFP conversions given the myriad of non LFP setups on older boats that are "working just fine". Training for these techs is essential but seemingly will take time.

I'd suggest that any readers of this thread ignore the numerous posters' comments about ABYC recommendations not being free, available etc as these comments are not always material to the subject at hand - how best to design, install and implement an LFP setup.

 

[CharlieJ]

@twistedtree:
Bravo Zulu!

@DDW #17
1. Note that the ABYC Standards are the minimum level of performance acceptable to be compliant.
2. Note that the NMMA inspects the first vessel off the boat builder's production line for compliance with the ABYC Standards in effect at the time of production. Each vessel is not inspected for compliance.

@bowball #19
I would consider LFP batteries with an internal BMS only if:
1. The individual BMS communicates outside of the case to notify the owner of conditions especially if an SOE limit is being approached.
2. The individual BMS communicates and coordinates with the other BMSes in the bank.

 

[Brooksie]

Also, don't take a slip near me...

 

[Alaskan Sea-Duction]

Good post. A few years back, I looked into converting over to LI batteries. What I learned very quickly was no room to install. Also, the cost didn't pencil out.
I use flood golf cart batteries. After 9 years of use, I replaced them this past fall. I good life out of them. They are Costco batteries at $100 each, and I have 9.

BTW, the OP stated this was a requirement of ABYC if installing LI. Sorry, ABYC does NOT establish regulations or laws they can ONLY recommend.

 

[twistedtree]

BTW, the OP stated this was a requirement of ABYC if installing LI. Sorry, ABYC does NOT establish regulations or laws they can ONLY recommend.

True, but the two things are really different. The ABYC specs define what's require to be compliant with the spec. Something is either compliant or it isn't.


That said, there are no laws, at least not in the US, that require compliance. You might require it as part of a new build or boat purchase agreement. Or your insurance company may require it. Or you may require compliance for refit work on your boat.


The big difference is that just because something isn't required to be compliant, doesn't make it compliant. So you can't skip over some thing because it's not required by law, then claim to your insurance company that it's compliant. Similarly, a tech can't skip over requirements because ABYC isn't required by law, then turn around and tell you that his work is compliant.


So you don't HAVE to do any of it, but then you also can't claim compliance.

 

[guy with a boat]

Good post. A few years back, I looked into converting over to LI batteries. What I learned very quickly was no room to install. Also, the cost didn't pencil out.
I use flood golf cart batteries. After 9 years of use, I replaced them this past fall. I good life out of them. They are Costco batteries at $100 each, and I have 9.

BTW, the OP stated this was a requirement of ABYC if installing LI. Sorry, ABYC does NOT establish regulations or laws they can ONLY recommend.

Fewer LFP batteries are required for similar (or increased) capacity. That should take up less space, not more.

The OP indicated his post is summarizing what is required in order to be compliant with ABYC. Whether or not you comply with ABYC is up to you, and maybe your insurer and possibly the buyer’s surveyor if you ever sell your boat.

 

[dannc]

Regarding memberships.

I have joined some organizations, in spite of the high cost, because the information I bought was worth the price. However, once I get the information, I drop the membership. Then there are other organizations I want to join, but the membership cost is high, and the value of the information from the organization is unknown, so I do not sign up.

Given how easy it is today to start up a membership with a credit card and having a revolving membership at low expense to the organization, I don't understand why these entities do not have a low cost membership. They could, and would, make more money off the memberships that lasted years vs someone just buying a one year membership and canceling, OR the people who never join because of the high cost.

Some of these organization seem to want exclusivity for some reason.

Later,
Dan