E-13 -- cells that comply

[sailingharry]

Originally Posted by crayiii

Do you realize how patronizing that sounds? Thankfully, you don’t make the talking rules. [emoji1787]

I’ll save my comments for those on the committee that actually make the decision. /smh/

Ok, I won't be patronizing. I'm genuinely interested in what safety improvements you'd make to the standard. I'm designing my system, and while I intend to make it E-13 compliant (and actually will be exceeding it, as pointed out in this thread), I'm more interested in making it actually safe, not compliant. If there is some additional feature or design practice that I can include, I'd love to hear what you suggest and why (why is important -- I'm including a low voltage alarm as suggested by ABYC because I think it is important, but not including a high voltage alarm because I think it is counter productive).


And a related note, "safety" is an interesting aspect of this standard. A large percentage of ABYC standards are safety related. Wire sizes, fusing, bilge blowers, propane sensors, CO monitors, etc, etc, etc. Very few are equipment reliability related -- there is no automatic shutdown of an engine on low oil, there is no temperature sensor on the exhaust to detect a failed water pump, there is no over voltage alarm to keep you from frying your AGM batteries. LFP batteries are arguably safer than any prior installed battery the industry has ever seen, regardless of any recommendations by ABYC. This standard is about 90% focused on equipment longevity, with the remaining 10% focused on avoiding sudden loss of power. I'm not sure there is a single item in the entire standard that is "safety" related, at least not in my sense of the word. Yes, you can argue that reliability of mission equipment is mission related, but ABYC doesn't tend to focus much on that. Some, yes, but mostly it's direct safety related.

[crayiii]

Originally Posted by sailingharry

Ok, I won't be patronizing. I'm genuinely interested in what safety improvements you'd make to the standard. I'm designing my system, and while I intend to make it E-13 compliant (and actually will be exceeding it, as pointed out in this thread), I'm more interested in making it actually safe, not compliant. If there is some additional feature or design practice that I can include, I'd love to hear what you suggest and why (why is important -- I'm including a low voltage alarm as suggested by ABYC because I think it is important, but not including a high voltage alarm because I think it is counter productive).


And a related note, "safety" is an interesting aspect of this standard. A large percentage of ABYC standards are safety related. Wire sizes, fusing, bilge blowers, propane sensors, CO monitors, etc, etc, etc. Very few are equipment reliability related -- there is no automatic shutdown of an engine on low oil, there is no temperature sensor on the exhaust to detect a failed water pump, there is no over voltage alarm to keep you from frying your AGM batteries. LFP batteries are arguably safer than any prior installed battery the industry has ever seen, regardless of any recommendations by ABYC. This standard is about 90% focused on equipment longevity, with the remaining 10% focused on avoiding sudden loss of power. I'm not sure there is a single item in the entire standard that is "safety" related, at least not in my sense of the word. Yes, you can argue that reliability of mission equipment is mission related, but ABYC doesn't tend to focus much on that. Some, yes, but mostly it's direct safety related.

I would be happy to provide my input on this. It’s about popcorn and movie time so I’ll give you a couple of thoughts.

First, hire someone like Ocean Planet to work with you on a design. They provide that service.

Have a separate charge and load bus

Have a backup power source for important loads.

Install an integrated system where everything communicates with each other.

Make sure you meet all your insurance companies requirements.

Obviously, that’s very high level.

[wholybee]

I'll share what I would add/change to E-13.

First, I am not against NMC or any other chemistry. And I think a restriction to only use LFP is shortsighted because it doesn't allow for as of yet available batteries. E-13 only makes passive comments about different chemistries and falls back often on "follow the manufacturer's directions." I would set some specific manufacturer and chemistry independent guidelines. I would look at thermal runaway temperatures and causes, and I would have specific requirements for batteries that fall into certain categories.

For example, a battery that is very difficult to get to go into thermal runaway, and when it burns, it burns at temperatures < some threshold, nothing special needs done over a Lead-Acid installation. Even a BMS would be a recommendation but not required.
A battery that is over some threshold, would need a BMS with certain requirements, perhaps a fire-proof installation box, maybe an audible temperature alarm.
Maybe the most energy dense and "dangerous" battery would need some full-on fire suppression system.

The above would have various thresholds on difficulty to start thermal runaway, temperature of thermal runaway, and size of bank in Wh.

I would also make a few distinctions between house batteries and propulsion batteries. Those batteries have different requirements, and the effect on safety of each if disconnected or goes dead is quite different.

The point is, that these would be based on actual properties of the battery, not arbitrarily saying one chemistry is safe, and another is not. After all of those requirements are defined, there could be a note "It is understood that an LFP battery will fall into category A, and an NMC battery will fall into category B." etc.

Nothing in what I envision would make current drop-in batteries non-compliant. LFP would fall into the category with the least requirement, and current LFP drop-ins meet them.

My complaints of E-13 are that mostly all it says is "follow manufactures directions." There are some specific BMS requirements, and the stupid alarm recommendation, but overall, it doesn't contribute very much to safety, it just directs readers to manufactures. Which I suppose on its own isn't bad for a first draft, except that there is a really wide range of quality and safety among manufacturers. I would expect E-13 to be as much a guide to manufacturers as to installers.

And whether or not it is factual or not that some manufactures influenced E-13, the effect of E-13 does discourage drop-in batteries, and even most BMS's. TE-13, with the alarm a requirement, would have made virtually every drop-in non-compliant, and mostly all BMS's less than about ~$1000 non-compliant. It would have been a huge gift to a very few companies that manufacture the most overpriced stuff.

[wholybee]

Originally Posted by sailingharry

Ok, I won't be patronizing. I'm genuinely interested in what safety improvements you'd make to the standard. I'm designing my system, and while I intend to make it E-13 compliant (and actually will be exceeding it, as pointed out in this thread), I'm more interested in making it actually safe, not compliant. If there is some additional feature or design practice that I can include, I'd love to hear what you suggest and why (why is important -- I'm including a low voltage alarm as suggested by ABYC because I think it is important, but not including a high voltage alarm because I think it is counter productive).


And a related note, "safety" is an interesting aspect of this standard. A large percentage of ABYC standards are safety related. Wire sizes, fusing, bilge blowers, propane sensors, CO monitors, etc, etc, etc. Very few are equipment reliability related -- there is no automatic shutdown of an engine on low oil, there is no temperature sensor on the exhaust to detect a failed water pump, there is no over voltage alarm to keep you from frying your AGM batteries. LFP batteries are arguably safer than any prior installed battery the industry has ever seen, regardless of any recommendations by ABYC. This standard is about 90% focused on equipment longevity, with the remaining 10% focused on avoiding sudden loss of power. I'm not sure there is a single item in the entire standard that is "safety" related, at least not in my sense of the word. Yes, you can argue that reliability of mission equipment is mission related, but ABYC doesn't tend to focus much on that. Some, yes, but mostly it's direct safety related.

The best thing you can do to ensure your LFP installation is safe is to follow E-10 and E-11. And ensure that your chargers all support LFP and are programmed properly. You can add a lot of complexity and extras, but none of that really makes it safer, and if you aren't following E-10 and E-11, it doesn't matter at all.

I wonder how many people are worried about meeting E-13 because they read about it everywhere, but haven't looked at 10 and 11?

[sailingharry]

Originally Posted by crayiii

I would be happy to provide my input on this. It’s about popcorn and movie time so I’ll give you a couple of thoughts.

First, hire someone like Ocean Planet to work with you on a design. They provide that service.

Have a separate charge and load bus

Have a backup power source for important loads.

Install an integrated system where everything communicates with each other.

Make sure you meet all your insurance companies requirements.

Obviously, that’s very high level.

If I paid people to work on my boat, I wouldn't have a boat.

What advantage does a charge and load bus provide? All my chargers and loads will connect to "the bus," although all chargers will be shut off by the bms.

I don't currently have a backup power source for critical loads. Why should I add that now? Actually, that's not true. At present, and in the future, I can flip one switch to isolate the battery and a second switch to bring the start battery on to house loads, so that is a backup. But I am upgrading my battery system not downgrading it, so I need for a backup is less than it used to be.

I will certainly have a system where things talk to each other. The BMS has a charge enable line that will disable all chargers, and a discharge enable line that will disable major non-critical loads (at present, that is just the inverter). It doesn't have a fancy name like can bus, but that is a communication system.

My insurance company isn't particularly difficult. They don't even ask that I tell them I am installing a new battery. You may have heard of them, BOAT/US.

[sailingharry]

Originally Posted by wholybee

The best thing you can do to ensure your LFP installation is safe is to follow E-10 and E-11. And ensure that your chargers all support LFP and are programmed properly. You can add a lot of complexity and extras, but none of that really makes it safer, and if you aren't following E-10 and E-11, it doesn't matter at all.



I wonder how many people are worried about meeting E-13 because they read about it everywhere, but haven't looked at 10 and 11?

Indeed. E-11 is much more relevant to safety than E-13. And I have been reading and following E-11 for as long as I've owned boats. That's where the real fire risk is.

Most of my charge sources are fully programmable and easy to control from the BMS with a charge enable output (Victron MultiPlus, Victron SmartSolar, and a couple of old Balmar regulators.). The two exceptions are my Watt and Sea and an old Victron multi voltage charger that was installed when the boat went overseas. Those two will have to go through a relay.

[tanglewood]

Originally Posted by wholybee

I'll share what I would add/change to E-13.

First, I am not against NMC or any other chemistry. And I think a restriction to only use LFP is shortsighted because it doesn't allow for as of yet available batteries. E-13 only makes passive comments about different chemistries and falls back often on "follow the manufacturer's directions." I would set some specific manufacturer and chemistry independent guidelines. I would look at thermal runaway temperatures and causes, and I would have specific requirements for batteries that fall into certain categories.

For example, a battery that is very difficult to get to go into thermal runaway, and when it burns, it burns at temperatures < some threshold, nothing special needs done over a Lead-Acid installation. Even a BMS would be a recommendation but not required.
A battery that is over some threshold, would need a BMS with certain requirements, perhaps a fire-proof installation box, maybe an audible temperature alarm.
Maybe the most energy dense and "dangerous" battery would need some full-on fire suppression system.

The above would have various thresholds on difficulty to start thermal runaway, temperature of thermal runaway, and size of bank in Wh.

I would also make a few distinctions between house batteries and propulsion batteries. Those batteries have different requirements, and the effect on safety of each if disconnected or goes dead is quite different.

The point is, that these would be based on actual properties of the battery, not arbitrarily saying one chemistry is safe, and another is not. After all of those requirements are defined, there could be a note "It is understood that an LFP battery will fall into category A, and an NMC battery will fall into category B." etc.

Nothing in what I envision would make current drop-in batteries non-compliant. LFP would fall into the category with the least requirement, and current LFP drop-ins meet them.

My complaints of E-13 are that mostly all it says is "follow manufactures directions." There are some specific BMS requirements, and the stupid alarm recommendation, but overall, it doesn't contribute very much to safety, it just directs readers to manufactures. Which I suppose on its own isn't bad for a first draft, except that there is a really wide range of quality and safety among manufacturers. I would expect E-13 to be as much a guide to manufacturers as to installers.

And whether or not it is factual or not that some manufactures influenced E-13, the effect of E-13 does discourage drop-in batteries, and even most BMS's. TE-13, with the alarm a requirement, would have made virtually every drop-in non-compliant, and mostly all BMS's less than about ~$1000 non-compliant. It would have been a huge gift to a very few companies that manufacture the most overpriced stuff.

Thanks. That's useful feedback. The notion of categorizing chemistries has come up. One challenge with such an approach is determining exactly where to draw the lines. It's conceptually easy, but in details can be quite difficult.


Ironically, much of what you are suggesting would further weaken the requirements, at least for LFP.



I agree that a lot is left to manufacturers, but that's because nobody else can know. Like all the parameters that make up the "safe operating envelope". Similarly for physical mounting, limits on parallel and serial wiring, etc.


To me, the alarming recommendation is about providing a way to affirmatively shut down chargers and/or loads before the situation escalates to a shutdown. This could happen because a charger has gone rogue and is over charging, or because there is enough of a cell imbalance that one cell is going to trigger a shutdown when externally is fine, and chargers are happily charging away. Same on a discharge. It also addresses the alternator over-voltage issue on a BMS disconnect by providing a way to shut it off before the disconnect.

[tanglewood]

Regarding safety requirements in E-13, I think there are a number that go beyond E-10 and E-11, though perhaps we all take them for granted.


- Requirement that there be a BMS.

- The definition of a Safe Operating Envelope for the battery, and a requirement to stay within it.


- The requirement to ensure chargers operate within the confines of the SOE. How you accomplish it is left open, but you need to do it.


- Limiting serial and parallel configurations to those allowed by the manufacturer.


- Having a disconnect switch controlled by the BMS that disconnects the batteries if they venture outside of the Safe Operating Envelope. It's the action of last resort. Yet there are plenty of systems from reputable manufacturers that don't have such a disconnect switch.


- Fusing requirements, especially with respect to AIC rating relative to short circuit current capabilities of Li-ion batteries, and the need to break banks up and fuse in segments if required.


- Cautions to build the system such that it can't damage other systems or parts, which covers the need to protect your alternator from damage on a BMS disconnect, and that you need to regulate your alternator so it doesn't get smoked.


- And a caution that a BMS disconnect can be disabling for critical system, and that you need to account for that in the system design.



I think these are all safety related.

[wholybee]

There was a time when LFP batteries were installed with simple active balancers, and no BMS. I have run across one was about 15 years old and still working fine. The BMS has proven important to protect the cells, but i don't think it has been shown to add to safety for an LFP battery. I would never recommend not having a BMS, and I don't have a problem with them being required, but strictly speaking I don't think they add safety to LFP. They do add safety to other Lithium Ion chemistries.

Safe operating envelope requirements apply to Lead Acid as well. The only real difference there is that basically all chargers conform to L-A parameters and only newer chargers conform to LFP. So that needs to be addressed in a conversion and many people take for granted that common chargers conform to an LA operating envelope and that they are different needs to be pointed out. Although not comprehensive or complete, this is addressed in some small way in E-10 (10.7.11 Batteries shall be charged by means that are appropriate to the type of batter being charged).

AIC is addressed in E-11 (11.10.1.2.2) and table 3B.

The disconnect switch operated by a BMS is an interesting one. I agree, there needs to be a disconnect operated by the BMS (if we agree a BMS is needed). But, there are a lot of installations where there is no disconnect, only that the BMS controls all the charging sources and can turn them off. So, if a charger malfunctions (for example there are cases of an MPPT failing as a short from the solar panel to the battery) then the BMS has no way of stopping it. I do not feel this is compliant, but there are apparently a lot of people who do. And they argue their complex system with CAN bus control, fancy Cerbo GX, and expensive wakespeed regulator is better than a simple BMS controlling a couple contactors and no other external communication. I think the simple system with relays is safer for the battery and less likely to fail.

Anyway, as so many things, it is a moving target and will improve with experience and feedback. As it stands, I think it is really easy to comply with E13, and if you install a system that doesn't, you probably did something that is not safe.

[sailingharry]

Originally Posted by wholybee

The disconnect switch operated by a BMS is an interesting one. I agree, there needs to be a disconnect operated by the BMS (if we agree a BMS is needed). But, there are a lot of installations where there is no disconnect, only that the BMS controls all the charging sources and can turn them off. So, if a charger malfunctions (for example there are cases of an MPPT failing as a short from the solar panel to the battery) then the BMS has no way of stopping it. I do not feel this is compliant, but there are apparently a lot of people who do. And they argue their complex system with CAN bus control, fancy Cerbo GX, and expensive wakespeed regulator is better than a simple BMS controlling a couple contactors and no other external communication. I think the simple system with relays is safer for the battery and less likely to fail.

Anyway, as so many things, it is a moving target and will improve with experience and feedback. As it stands, I think it is really easy to comply with E13, and if you install a system that doesn't, you probably did something that is not safe.

I cut out the early part of your quote because I agree 100% and it is (should be) non-controversial.


The BMS disconnect. First, I agree with your premise that a BMS is not really needed, but still a really really good idea. Which leads to BMS disconnect.


Some subscribe to an long-standing philosopy of a dual bus. One to turn off the chargers, one to turn off the loads. I disagree. First, some devices are both -- where do you connect the inverter/charger? Second, some CAN be both -- if you develop some sort of fault in your alternator such that it draws 10A continuous (short in field? It draws 10A). When your battery is flat, it still never disconnects. And, most can be controlled with CANbus (if you go ultra complex) or with a charge-enable wire. So, in my design:
* Almost everything connects to a main bus (two charge sources go through a contactor on the way to the main bus).
* The BMS signals disconnect of charge sources when appropriate (much like a charge bus used to do). No CANbus, just an off-off wire.
* The BMS signals disconnect of inverter (only high load device on the boat) at 10% SOC. This also sounds an alarm, letting me know there is only 60Ah left in the bank (8 hours at normal loads). If I'm aboard, I take immediate action (turn on engine, turn off fridge, abandon ship, whatever). If I'm not on board, the only meaningful load is the fridge, which probably counts as "mission critical!"
* In extremely unlikely cases (because the list above has pre-managed things) of high/low voltage, the main disconnect opens and ALL connections to the battery are lost.

As an aside, I have selected the BlueSeas remote battery switch as my contactor. It's a zero load (latching) contactor, but comes with the ability to manually lock it out (for maintenance, winter layup, etc) and the ability to manually close it (if for whatever reason I want to override the BMS -- say it has gone loony, or it tripped on low voltage and I need to begin charging.)

Yes, E-13 is easy to comply with. And that's not because "it is watered down." It's because the standard as written is fairly solid, even if it is a first iteration.

[sailingharry]

Originally Posted by wholybee

The best thing you can do to ensure your LFP installation is safe is to follow E-10 and E-11.

Just a quick note to say thankyou. I responded earlier about compliance with E-11, and that's the one that all of us should have readily at hand. It's complex, and covers a lot of cases with a lot of exceptions. Only an experienced (and actively working) ABYC electrician will have all of that in their mind -- and even then, they probably have to reference it. I use it a lot.


I had all but forgotten about E-10. I've read it, but most of it is very simple and easy to internalize. Anyone who's been around knows most of it (restrain batteries, cover terminals, provide ventilation, acid proof, etc). At your prompting I just re-read it again. No great revelations, but it's still good to re-read it. And I did re-learn that my boat (1998), and the one before it (1979) have completely ignored the ventilation part.....



So, thanks for bringing it up, and thanks for prompting me to re-read it. Probably wouldn't hurt to re-read A-31 either.

[tanglewood]

It's really interesting to hear the varied views here. On one hand we have people who feel that standard should require UL 1973 certification, which goes way beyond requiring a BMS. Then on the other hand we have people who don't think a BMS is even required for LFP, or at least not required for safety.


I can say that the intent of E-13 is safety, not battery protection. There were plenty of discussion about this, and the goal of the standard is NOT to keep you from ruining your batteries. It IS to meant to keep the power system from harming people primarily, and to that end to keep them from endangering the boat. Many of these protective measures also make it harder to ruin the batteries, but that's not the objective - it's a side effect. Some types of batteries become very dangerous if overcharged, so by a defective charger that doesn't stop when it's supposed to. Or that doesn't stop because the BMS itself went tits up. And some batteries become dangerous if your drain them stone dean, then try to recharge - or at least that's what one credible manufacturer told me. My experience is with LFP and I didn't think such a thing could be dangerous, just ruinous to your batteries and bank account.



I totally agree that the risk profile of LFP is very different from other Li-ion chemistries, but for better or worse, E-13 does not distinguish and leaves those differences to the definition of the SOE for the battery. I think there is a valid argument that what's needed to keep LFP safe is different from what's needed to keep other types safe, and think I said that early on in this thread, or maybe it was another one. I've lost track. Maybe that's how the standard will evolve, but it's not easy to codify that in a generic way. For me personally, if I were to have a large NMC or similar pack on my boat, like for propulsion, I would want it to be listed for UL 1973, or one of the DNV standards. I do think a much higher level of rigor is required in such a case. But that's my own opinion.

[sailingharry]

Originally Posted by tanglewood

It's really interesting to hear the varied views here. On one hand we have people who feel that standard should require UL 1973 certification, which goes way beyond requiring a BMS. Then on the other hand we have people who don't think a BMS is even required for LFP, or at least not required for safety.

I can say that the intent of E-13 is safety, not battery protection.

I totally agree that the risk profile of LFP is very different from other Li-ion chemistries, but for better or worse, E-13 does not distinguish and leaves those differences to the definition of the SOE for the battery.

I want to be clear as I start this post that I am not trying to be argumentative. I understand the challenges ABYC faces when putting together a standard like this. And that for now at least, they lump all chemistries together. At least from my perspective, it doesn't bother me as I find the standard to be common sense and worthy of following.

As a thought experiment to investigate edge cases, imagine a totally unmanaged LFP bank. No balancing, no disconnects, no nothing. Four cells wired together and tossed into the battery compartment (religiously following E-11 and E-13 of course). The owner is somewhat observant and attentive, and keeps charging in something approaching the optimum operating zone. What is the most likely safety related potential failure? Fire? Some sort of off-gassing?

As I said, not trying to be argumentative. But these kinds of explorations can be insightful even for a well-built system that shouldn't approach those failure modes. Knowing the disaster your installation is trying to avert puts context on the work you are installing. As an example, understanding how fuses protect wires from fires makes it easy to understand that a fuse gets placed close to the battery on a battery cable, but not close to an alternator (rather, at the far end).

[crayiii]

Some view ABYC standards as something to strive for, others view the standards as a minimum starting point.

For us, we exceed most all “requirements” for safety gear, equipment installations, maintenance, reefing points, etc.

Not saying that’s the best approach (it can get expensive) but that’s our approach and because I believe it’s a good thing, that’s where my comments are generally coming from.

When we did our lithium conversion, our ABYC installer gave a quote that included significant upgrades to many systems and a lot of the factory wiring (even on the AC side). They were very clear that they would only do the job as they bid it because that was their safety standard. I appreciate that.

[sailingharry]

That's quite a firm. Every job requires updating the entire boat to way above current standards. Would they have required that same update if you'd simply replaced your AGM with new AGM? I would hope so, fire is fire and it doesn't matter what kind of battery you use.