Upgrading Inverter/charger

[dlochner]

I don’t think this is correct. There is nothing I can find in E-11 or E-13 with this requirement. E-13 does require the chargers to be programmed to meet the battery manufacturers charge profile, but not necessarily communicate with the BMS. Also the BMS is required to be able to disconnect without reliance on the programmed functions of the chargers. While it’s certainly nice to have a BMS that will shutdown a compatible regulator before disconnecting the battery, it‘s not a requirement.

First, ABYC Standards are not mandatory. E13.7.4 (see below) says the BMS should notify the operator if it is going to shut down. The intention for that standard is to protect the Alternator from a voltage spike due to a BMS shutdown. The problem with the standard as written is the operator (a human) probably can't respond quickly enough to meet the intent of the standard. In practice this is met by having the BMS communicate to the Regulator to cut the field current, shutting down the alternator.

My earlier statement was a bit broad, however the essence was the BMS should talk to the Regulator to be ABYC Compliant. And just like our NMEA 2000 networks not every device uses or can use all the data on the network. I would expect the Victron network will be similar. I'll know more in another year as I'm working on and learning about a 19Kwh LFP system on a boat.

13.7.4 An output disconnect device shall be capable of disconnecting the output immediately when operating under
the battery's or the battery system's maximum specified rate of discharge.
NOTES:
1. An alternative power source is recommended for critical systems (e.g., engine starting, propulsior
navigation lights, etc.) that may be affected if a BMS shuts down the battery. The alternative power sourc
c a n b e a n o t h e r lithium ion b a t t e r y
2. If a shutdown condition is approaching, a battery system should notify the operator with a visual and/or
audible alarm before disconnecting the battery from the DC system.
3. BMS(s) may suddenly and unexpectedly disconnect a battery from loads and charging sources.

 

[Johann]

First, ABYC Standards are not mandatory. E13.7.4 (see below) says the BMS should notify the operator if it is going to shut down. The intention for that standard is to protect the Alternator from a voltage spike due to a BMS shutdown. The problem with the standard as written is the operator (a human) probably can't respond quickly enough to meet the intent of the standard. In practice this is met by having the BMS communicate to the Regulator to cut the field current, shutting down the alternator.

My earlier statement was a bit broad, however the essence was the BMS should talk to the Regulator to be ABYC Compliant. And just like our NMEA 2000 networks not every device uses or can use all the data on the network. I would expect the Victron network will be similar. I'll know more in another year as I'm working on and learning about a 19Kwh LFP system on a boat.

Sure, compliance with ABYC standards is not required by law. But if you want a compliant installation you should follow their "shall" and "must" instructions, and consider the recommendations and "should" statements.

But with regard to E13.7.4, that applies to battery output, not charger output. The intent is that the operator has notice to prepare an alternate source of power to critical systems. It is not a suggestion that the BMS should have the ability to shutdown an input device like the alternator regulator.

 

[HoosierSailor]

Thanks everyone! I appreciate the helpful tips and advice. Let me provide a little more background. My wife and i are full time liveaboards and we are currently in the Exumas. The Freedom 20 inverter charger we have is original to the boat and slowly on the way out. It is starting cut out at high rates of charge when I have the generator running unless I open the rear door on the engine compartment to provide additional cooling. I also hope to upgrade to LifePo lithium later this year from the 2 AGMs that we have. So an upgrade is in order. I also plan to upgrade the solar from 400 watts so that I hopefully won't have to run the generator or the engine as much. I like the Victron line and have a Victron battery monitor and solar control already so I believe it makes sense. I also have a watermaker that I would like to be able to run off the inverter/lithium setup without have to start the generator. Currently the 2000 watt inverter doesn't quite cut it.

I was just hoping maybe someone with a similiar boat had already installed one and came up with a good idea of where to mount it.

Thanks

 

[colemj]

Well I wouldn't say Victron uses sanskrit, but they do use actual electrical and engineering terms.

That part is the same for every manufacture. With Victron, you need to learn the language of Ve.net, Ve.bus, Ve.can, VCC, DVCC, etc. Made even more obfuscated in that they don't have any manuals that describe things well. Victron really relies on professional installers and pushing their customers to such.

Victron is the only manufacturer whose inverter/chargers cannot be programmed or setup without plugging into a computer through a specialized cable and running complicated software. They used to offer an external control panel that allowed all of this (I have one and it's brilliant and does everything the computer can), but they got rid of it because it gave too much control to the user.

The people that like Victron are pretty dedicated to it.

As I mentioned, I do like our Victron gear, and have bought it several times. Most of the people who are "dedicated" to Victron are the ones that have entire centralized Victron ecosystems, and many of them were not installed by the user, and problems are incomprehensible to them. The Victron forums bear this out. Otherwise, there are equal standalone inverter/charger options, and better solar controller options than Victron. Definitely better batteries and BMS's.

Mark

 

[colemj]

It is not a suggestion that the BMS should have the ability to shutdown an input device like the alternator regulator.

That's correct. It is not a recommendation at all with ABYC that the devices communicate. The "notification" needs to be visual or audio, so that part is necessary regardless of communication. It also could simply open a relay that interrupts power to the regulator/controller, thus automatically shutting things down without any communication at all.

Mark

 

[Stu Jackson]

thus automatically shutting things down without any communication at all.

Mark, how does one do this?

 

[colemj]

Mark, how does one do this?

As I mentioned, just use the BMS warning output to open a relay that shuts down power to the regulator. Wire the regulator power lead through the normally closed terminals of an inexpensive relay, and the BMS's "stop charging" output to the relay's solenoid. When the BMS activates the solenoid, the NC circuit opens and power is cut to the regulator.

Mark

 

[Stu Jackson]

As I mentioned, just use the BMS warning output to open a relay that shuts down power to the regulator. Wire the regulator power lead through the normally closed terminals of an inexpensive relay, and the BMS's "stop charging" output to the relay's solenoid. When the BMS activates the solenoid, the NC circuit opens and power is cut to the regulator.

Mark

All true IF the BMS has an output function.

 

[colemj]

All true IF the BMS has an output function.

Agreed, but ABYC states that the BMS must give an audio or visual warning before disconnecting. I'm not sure how that would be done without some type of output on it. The response was to the suggestion that the BMS must communicate to the regulator to shut it down. I was pointing out that it didn't have to, and there were other ways to shut down a regulator without communication if wanted.

Mark

 

[MFD]

Agreed, but ABYC states that the BMS must give an audio or visual warning before disconnecting. I'm not sure how that would be done without some type of output on it. The response was to the suggestion that the BMS must communicate to the regulator to shut it down. I was pointing out that it didn't have to, and there were other ways to shut down a regulator without communication if wanted.

Mark

I thought this was a recommendation, and not a requirement?
And also a fairly new recommendation at that.
Genuinely curious.
Thanks.

 

[dlochner]

I thought this was a recommendation, and not a requirement?
And also a fairly new recommendation at that.
Genuinely curious.
Thanks.

Nothing in ABYC standards is mandatory. The standards are best considered a compendium of best practices for recreational boats. When the words, should and shall are used they are used in consideration of being compliant with standards.

For most of us working on older boats and retrofitting equipment the standards are aspirational. Two examples on my boat. The Class T fuse on the LFP battery output is not 7 inches away, it is about 8 or 9 inches away and unsheathed. The ELCI breaker is supposed to within 10 wire feel of the inlet, mine is a bit further away because it just wansn't practical to meet the 10' requirement for compliance.

It is also helpful to know how the standards are developed. Basically a committee meets and discusses an issue and then comes up with a consensus recommendation. Committee members are typically people known in their field and have some expertise. Many of the recommendations are not based on science or data, just well informed opinions by committee members. Thus violating the 7" cable requirement by a few inches is not a big deal. Certainly, my surveyor wasn't worried about it and didn't pull out his tape measure on a recent survey.

And just to keep things interesting, the standards are periodically revised, this is especially true for electrical and battery systems. Look for an update this spring.

 

[MFD]

Haha,

<quote>Basically a committee meets and discusses an issue and then comes up with a consensus recommendation. Committee members are typically people known in their field and have some expertise. Many of the recommendations are not based on science or data, just well informed opinions by committee members. Thus violating the 7" cable requirement by a few inches is not a big deal.</quote>

I actually opened a thread over on Sailing Anarchy asking why 7" was decided on in a few different areas for wiring. Presuming it was some sort of balance on a committee. My battery cables are also too long - 12", but I did put split duct on them (allowable up 72"?) even though I can't possibly see any way there could possibly be any chafe on a segment that short that doesn't go through any bulkheads or such. At some point I guess they just have to pick a number, and common sense when looking at a given installation after that?

 

[Johann]

I thought this was a recommendation, and not a requirement?
And also a fairly new recommendation at that.
Genuinely curious.
Thanks.

The standard uses the word “should” here, which means it is to be considered, but not mandatory for compliance. The words “shall” and ”must” indicate conditions that are mandatory if you are to be considered in compliance with the standard.

 

[colemj]

The standard uses the word “should” here, which means it is to be considered, but not mandatory for compliance. The words “shall” and ”must” indicate conditions that are mandatory if you are to be considered in compliance with the standard.

Should is the strongest compliance term. There is no "shall" or "must" terminology. These are recommendations, not requirements. "Consider" is a used as a weaker term that doesn't directly denote terms of compliance.

Mark

 

[colemj]

I actually opened a thread over on Sailing Anarchy asking why 7" was decided on in a few different areas for wiring. Presuming it was some sort of balance on a committee. My battery cables are also too long - 12", but I did put split duct on them (allowable up 72"?) even though I can't possibly see any way there could possibly be any chafe on a segment that short that doesn't go through any bulkheads or such. At some point I guess they just have to pick a number, and common sense when looking at a given installation after that?

I too have always been confused with this requirement. Like yours, we have a 12" positive and 12" negative lead from our battery. This 12" is straight through free space to a fuse holder on the positive and a shunt on the negative, both mounted on a bulkhead. I fail to see why that extra 5" of 4/0 wire now makes this vulnerable, and just what the loom covering is supposed to accomplish that mitigates this. Ironically, I could have made these leads 7", but the stiff 4/0 wire would have been under a lot of strain at each end connection, which is more of a risk than another 5" that keeps everything strain-free.

Apparently, I could use 7" of wire bent into an S-shape and passing through a bulkhead without any worry at all.

That is not the only problem I have with some ABYC recommendations. I think that a group of people sitting around trying to think up of all possible risks and strategies to prevent them often can't see the forest of implementation practicality for the trees of hypothetical risk.

Mark

 

[colemj]

I thought this was a recommendation, and not a requirement?
And also a fairly new recommendation at that.
Genuinely curious.
Thanks.

Yes, recommendation. Nothing is mandatory (who would enforce that?).

However, they are often talked about as "requirements" because they become so when having work done by a professional on the boat, or selling a boat that will get a survey, or getting insurance - where all of these use them as requirements. Well, particularly insurance - "marine professionals" may or may not depending on their standards, and surveyors aren't necessarily well-versed in them, or are more forgiving of practical limitations in the specific boat.

Mark

 

[Johann]

Should is the strongest compliance term. There is no "shall" or "must" terminology. These are recommendations, not requirements. "Consider" is a used as a weaker term that doesn't directly denote terms of compliance.

Mark

The “shall” “‘must” “should” “ may” convention is used to denote levels of compliance by regulation and standard writers across many different agencies. The FAA uses it. ISO uses it. NASA uses it. And yes, the ABYC uses it.. Do you have access to the standards? You can get a free 5 day ABYC membership and see for yourself.

Here are some links that explain the use of the terminology.

ABYC 2025 Standards Week, improving safety and evolving standards

ABYC published their first lithium-ion battery standard in the summer of 2022. At the time, I wrote an entry on the standard and expressed some concerns about some requirements not in the standard as well as a strong reliance on manufacturers’ documentation and specifications. My first paragraph...

panbo.com

Using the Correct Requirements Terms – Shall, Will, Should

When writing requirements, many international standards, including ISO, use the 'shall', 'will', 'should' convention. See how it's done!

argondigital.com

Appendix C: How to Write a Good Requirement - NASA

Functionality

www.nasa.gov

ISO - Foreword - Supplementary information

www.iso.org

https://www.faa.gov/air_traffic/publications/atpubs/atc_html/chap1_section_2.html

Where can I find guidance on the use of ‘shall’, ‘must’, ‘should’ and ‘may’ in the Agency’s rulemaking publications and generally in EU legislation? | EASA

This question relates to the English writing standards used in Community legislation. Points 10.23 to 10.32 of the English Style Guide, prepared by the European Commission’s Directorate-General for Translation, provide guidance concerning the use of modal verbs in legislation, contracts and the...

www.easa.europa.eu

 

[dlochner]

Should is the strongest compliance term. There is no "shall" or "must" terminology. These are recommendations, not requirements. "Consider" is a used as a weaker term that doesn't directly denote terms of compliance.

Mark

From the ABYC Standard I quoted earlier:

"13.7.4 An output disconnect device shall be capable of disconnecting the output immediately when operating under
the battery's or the battery system's maximum specified rate of discharge."

 

[colemj]

Do you have access to the standards?

Yes, I do. And nowhere in the TE-13 standard covering lithium batteries are the words "shall" or "must" used.

Mark

 

[colemj]

From the ABYC Standard I quoted earlier:

"13.7.4 An output disconnect device shall be capable of disconnecting the output immediately when operating under
the battery's or the battery system's maximum specified rate of discharge."

Sorry, I wasn't clear. The discussion was addressing the TE-13 standard, specifically about a lithium battery BMS alarm. Nowhere in that standard is the term "shall" used.

It is possible that this standard has been updated with that change from the one I have.

Mark