As promised, now this has been approved and released by the two organisations... 🙂 

 

Before reading it and exploding with righteous wrath, please read *all* of it -- especially the introduction! -- and remember a few things:

 

1. This is intended to describe "best practice" in LFP installs, not dictate every single thing which *must* be done -- it's down to the installer (or "competent person***") to decide what is necessary in a given installation.

2. It refers to domestic LFP installs because these are far more common than propulsion ones -- but that doesn't mean the same "best practice" doesn't apply to them too.

3. It was written by the panel of the Joint Battery Safety group, which includes boaters with LFP batteries and hybrid boats, and is definitely not intended to be pro-regulation-writer or anti-boater -- it's intended to give the best practical advice available based on current knowledge of LFP batteries and their safety.

 

For example, the section on insurance says this:

 

"Some policy conditions may be impractical (e.g. daylight only charging) or in the case of small AVD fire extinguishers, likely ineffective, and dangerous to attempt to use against a domestic sized battery bank fire. Other stipulations will be necessary such as manufacturer- approved chargers. In all cases make sure the measures are practical and workable and highlight to the insurer where a condition seems impractical or unachievable."

 

This is prompted by the fact that the "lithium-capable handheld fire extinguishers" that some insurers have started to require are about as much use as a chocolate fireguard faced with an install-size LFP battery fire, and that fire brigade advice is not to try and fight such a fire but get out ASAP (also mentioned elsewhere in the Guidance Note) -- and having such extinguishers may encourage people to do the wrong thing, meaning they have a negative safety contribution rather than a positive one... 😞 

 

I expect the biggest bone of contention will be the recommendation that LFP batteries should vent to outside the boat not into the living space, because this has not been recommended previously (at least, not generally speaking) -- but it's there for similar reasons to LA batteries and LPG cylinders (which boaters accept as "normal"), with the added factor that the emitted gases are not only flammable/explosive and can be large in volume (see ABC dayboat) but are also toxic if inhaled.

 

This is the first released version of the note, and the hope is that it can be used to reach a common understanding between boaters, installers, insurers and safety organisations (e.g. BSS/RCR) about what constitutes a safe LFP installation, without placing ridiculously difficult or costly requirements on this which will make it unfeasible. Any sensible comments/suggestions will be noted and taken into account for the next release of the document -- there's no fixed date for this, but it will undoubtedly happen at some point because that's how documents evolve... 🙂 

 

*** there is currently no definition of what a "competent person" is for boat LFP installs/approval, and that is one of the big issues the industry has to address soon... 😞 

CA IWA Guidance Note Domestic Lithium Battery Installation V1.pdf

 

For background, here's a note I sent on the "LFP venting" issue to a friend who has LFP batteries under his bed... 😞 
 

"I understand why you're not happy with that statement, but unfortunately those are the facts -- if LFPs are abused (which of course should *never* happen...) they can give off large quantities of toxic/flammable/explosive gases, as in the ABC dayboat. These can be *far* bigger volumes than those given off from LA batteries, and IIRC (large) LA batteries already have a BSS/RCR requirement for ventilation -- do they also specify isolation from living spaces? If these gases build up inside the boat and are ignited instead of venting outside, we all now know what can happen in the worst case... 😞

 

This hazard was simply not appreciated before the ABC fire, even though regulation drafters (e.g. ISO) were well aware of it this was (I believe) seen as a largely theoretical concern that nobody needed to really worry about, after all everyone knew how safe LFPs were and that it was fine to install them in a rack or cupboard inside the boat or under the bed -- which is what you did. And indeed they're still being installed like this today, see recent posts on CWDF and on FB -- in this case from Ed at Four Counties who I expect would definitely seen as a "competent installer".

 

Whether the ventilation and separation from living space become legal (or insurance-driven) requirements as opposed to "best practice" remains to be seen, but both these are very definitely "best practice" (if only to avoid possible future problems!) so they should be in the Guidance Note.

 

If they do become enforced in future then this is indeed unfortunate for boaters (like you) who have installed LFP inside the boat and might find it difficult to meet the requirements, at least without significant modification -- and from what I've seen there are likely to be quite a lot of these, especially for domestic installs but even some electric/hybrid boats where fixing the problem could be much more difficult do to battery size/weight.

 

You do have my sympathy, but I'm afraid this is one risk of adopting new technology before the rules have caught up with it -- especially if a hazard emerges which was previously unknown or seen as unimportant, which is what has happened here with LFP."

Edited August 8Aug 8 by IanD
notes on venting added

Yea it’s not too bad. I think the requirement for separate “installer” and “user” login privileges is a bit far fetched. Yes you do get that with eg domestic solar/battery systems, but as far as I know the current crop of tech designed for boats doesn’t have that capability. There is no point in proposing a standard if none (or virtually none) of the current tech supports it.

 

Also the thing about ventilation is pretty vague. Obviously we know why it’s there, but it is fairly meaningless without specifying what the ventilation has to achieve. If looking to cater for the major cell rupture scenario à la ABC boat then the vent has to be pretty big and close coupled to the battery compartment. On the other hand it might be better to prioritise not getting into that situation in the first place!

 

In our case the Li batteries are in the engine bay which is under boards within a trad stern. And the engine bay is vented to outside through some hooded vents on the rear bulkhead. But of course the same vented space runs under the cabin as bilge to some other vents at the front. So we meet the requirement (batteries not in a domestic space and vented to outside) but if there was to be a cell rupture, the rate of release of gas would probably overpower the vents and the gas would leak into the residential space. So a compliance with the letter but failing to meet the objective. 
 

Also our BMS doesn’t limit max current, but there is a 500A fuse very close to the battery.

 

And then there is the different battery chemistries - “should remain electrically separated”. So it’s not OK to have LA battery negative connected to Li battery negative? I don’t think that is what was meant, but it’s what is said.

 

Also very verbose (designed by committee, where words are added to satisfy each committee member’s bonnet bees). Needs to reduce the word count to about 50%!

39 minutes ago, nicknorman said:

Yea it’s not too bad. I think the requirement for separate “installer” and “user” login privileges is a bit far fetched. Yes you do get that with eg domestic solar/battery systems, but as far as I know the current crop of tech designed for boats doesn’t have that capability. There is no point in proposing a standard if none (or virtually none) of the current tech supports it.

 

Also the thing about ventilation is pretty vague. Obviously we know why it’s there, but it is fairly meaningless without specifying what the ventilation has to achieve. If looking to cater for the major cell rupture scenario à la ABC boat then the vent has to be pretty big and close coupled to the battery compartment. On the other hand it might be better to prioritise not getting into that situation in the first place!

 

In our case the Li batteries are in the engine bay which is under boards within a trad stern. And the engine bay is vented to outside through some hooded vents on the rear bulkhead. But of course the same vented space runs under the cabin as bilge to some other vents at the front. So we meet the requirement (batteries not in a domestic space and vented to outside) but if there was to be a cell rupture, the rate of release of gas would probably overpower the vents and the gas would leak into the residential space. So a compliance with the letter but failing to meet the objective. 
 

Also our BMS doesn’t limit max current, but there is a 500A fuse very close to the battery.

 

And then there is the different battery chemistries - “should remain electrically separated”. So it’s not OK to have LA battery negative connected to Li battery negative? I don’t think that is what was meant, but it’s what is said.

 

Also very verbose (designed by committee, where words are added to satisfy each committee member’s bonnet bees). Needs to reduce the word count to about 50%!

Actually you're wrong about separate access privileges -- my boat does that, as do any boats using Victron kit, and also some other suppliers -- with Victron there are actually 3 levels of access with different privileges (and the critical internal BMS settings with NG battery/BMS can only be changed remotely by Victron updating the software).

 

Without this requirement there's nothing to stop a naive end user fiddling with the settings and getting them wrong -- and bear in mind that several of the suggested causes of the ABC event come down to bad programming/setup.

 

As the document says -- also the ISO standard -- it's not possible to give any exact specific requirements (e.g. for ventilation) because this is completely system-dependent, along with all the other details like wire sizes and operating temperature limits. It's the responsibility of the installer to get all that right -- this document is to help boaters ask the right questions, not answer them.

 

I expect the meaning of "electrically separated" would be obvious to most people not trying to find fault by nit-picking... 😉

 

If you think it can be shortened by 50% without losing the meaning, then might I suggest you try and do just that so we can all see how easy it is?... 🙂

Edited August 8Aug 8 by IanD

 

 

 

 

 

 

Edited August 8Aug 8 by MtB

2 minutes ago, MtB said:

And to lighten the mood here is a nice video of some American bro's expensive-looking electric bike spontaneously catching fire and burning itself out while they clearly have no idea what to do. (Answer - run away! Well actually someone did know what to do - video it and post it on Youtube.)

 

Ignore that they say "bro" a lot....

 

 

For crying out loud, can we please keep the usual non-LFP "lithium battery fire" videos out of what was intended to be a serious thread?

And there was me thinking you might be interested in some feedback. I am so stupid! I should have realised it’s transmit only.

Edited August 9Aug 9 by nicknorman

I would imagine this will all come into force about the same time as the problem gets side-stepped by Sodium batteries becoming cheap enough to replace LFPs in boats. 

 

 

 

 

2 hours ago, nicknorman said:

And there was me thinking you might be interested in some feedback. I am so stupid! I should have realised it’s transmit only.

of course it is, these are the experts, they have pronounced... how dare you question them....    🤣😂😉

 

Semi joking of course.   Thanks for Sharing @IanD 

 

having only glanced at it my thought is there isn't really anything to get exercised about. For most capable DIY installers it doesn't amount to a hill of beans, but could provoke some thoughts which is a good thing.  But, if I was paying a for a professional install and/or didn't know much about electrics/batteries then i think it gives some useful 'this is what you should expect' guidance.  if it calms down the hyperbole stirred up by idiots and settles down the insurance company nerves then its done a good job. 

 

by way of a laugh here is the one and a bit page summary AI produced for me, from the 11 pages, which does make it useless and again shows the  I in AI doesn't stand for intelligence. 

 

This document provides safety guidance and best practices for installing and maintaining lithium iron phosphate (LiFePO4) batteries on leisure craft.
System Design and Sizing
Owners should recalculate energy needs based on daily consumption and peak loads before selecting batteries.Batteries must have clear manufacturer data, confirming chemistry, capacity, C rating, and safe operating limits.
Installation Environment and Location
Batteries should be installed in a dry, secure, ventilated space isolated from living areas.Proper mounting, protection from water, vibration, impact, and following manufacturer instructions are essential.
Charging Compatibility and Integration
All charging sources, including alternators, shore chargers, and solar, must be compatible with the battery and BMS.Alternator protection is critical to prevent overheating, with external regulation or current limiting as needed.
Wiring, Protection, and System Components
Cables, fuses, and circuit breakers must be rated for fault and continuous currents.Proper labeling, secure connections, and avoiding bypassing safety devices are vital for safety.
Battery Management and Monitoring
The BMS must keep the battery within safe limits and protect against overcharge, over-discharge, and temperature issues.Owners should understand alarm signals, fault codes, and system shutdown procedures.
Safety, Emergency Planning, and Fire Prevention
Smoke and CO alarms should be installed; battery off-gassing requires careful handling.Emergency plans must include system isolation, evacuation procedures, and providing battery details to responders.
Maintenance, Inspection, and Record Keeping
Regular checks of connections, alarms, ventilation, and battery health are necessary.Owners should keep comprehensive documentation, including manuals, wiring diagrams, and installation records.
Insurance and Documentation
Owners must inform insurers before installation and ensure compliance with policy conditions.Maintaining an evidence pack with all relevant data supports claims, resale, and troubleshooting.
 

4 hours ago, nicknorman said:

And there was me thinking you might be interested in some feedback. I am so stupid! I should have realised it’s transmit only.

I was looking for sensible feedback, which your comment about isolation certainly wasn't. Your last comment was not helpful either -- trust me, early versions were longer still... 😉

1 hour ago, MtB said:

I would imagine this will all come into force about the same time as the problem gets side-stepped by Sodium batteries becoming cheap enough to replace LFPs in boats. 

 

 

 

 

Quite possibly, but the problem right now is LFP not sodium-ion... 😉

I'd recently moved the Li batt from the cabin to the engine hole in anticipation of this sort of thing. Nothing in there that is a huge surprise. We've had a lot of spoilers while it was being drafted!

2 minutes ago, Jen-in-Wellies said:

I'd recently moved the Li batt from the cabin to the engine hole in anticipation of this sort of thing. Nothing in there that is a huge surprise. We've had a lot of spoilers while it was being drafted!

That's why I kept dropping them, to try and persuade boaters not to do an LFP install in a way that they might regret in future... 😉

Who exactly are the “Joint Battery Safety group” have they any Government, Health & Safety regulator powers or authority?

 Any link to their website or to any info to what makes them an authority on this matter. As it says boaters with LFP batteries and hybrid boats. I thought the builders fitting and installing these boats would have been better equipped to advise, than someone that’s just bought a boat with no experience of fitting a Lithium system unlike the installers.

Edited August 9Aug 9 by BoatingLifeUpNorth2

3 hours ago, jonathanA said:

of course it is, these are the experts, they have pronounced... how dare you question them....    🤣😂😉

 

Semi joking of course.   Thanks for Sharing @IanD 

 

having only glanced at it my thought is there isn't really anything to get exercised about. For most capable DIY installers it doesn't amount to a hill of beans, but could provoke some thoughts which is a good thing.  But, if I was paying a for a professional install and/or didn't know much about electrics/batteries then i think it gives some useful 'this is what you should expect' guidance.  if it calms down the hyperbole stirred up by idiots and settles down the insurance company nerves then its done a good job. 

 

by way of a laugh here is the one and a bit page summary AI produced for me, from the 11 pages, which does make it useless and again shows the  I in AI doesn't stand for intelligence. 

 

This document provides safety guidance and best practices for installing and maintaining lithium iron phosphate (LiFePO4) batteries on leisure craft.
System Design and Sizing
Owners should recalculate energy needs based on daily consumption and peak loads before selecting batteries.Batteries must have clear manufacturer data, confirming chemistry, capacity, C rating, and safe operating limits.
Installation Environment and Location
Batteries should be installed in a dry, secure, ventilated space isolated from living areas.Proper mounting, protection from water, vibration, impact, and following manufacturer instructions are essential.
Charging Compatibility and Integration
All charging sources, including alternators, shore chargers, and solar, must be compatible with the battery and BMS.Alternator protection is critical to prevent overheating, with external regulation or current limiting as needed.
Wiring, Protection, and System Components
Cables, fuses, and circuit breakers must be rated for fault and continuous currents.Proper labeling, secure connections, and avoiding bypassing safety devices are vital for safety.
Battery Management and Monitoring
The BMS must keep the battery within safe limits and protect against overcharge, over-discharge, and temperature issues.Owners should understand alarm signals, fault codes, and system shutdown procedures.
Safety, Emergency Planning, and Fire Prevention
Smoke and CO alarms should be installed; battery off-gassing requires careful handling.Emergency plans must include system isolation, evacuation procedures, and providing battery details to responders.
Maintenance, Inspection, and Record Keeping
Regular checks of connections, alarms, ventilation, and battery health are necessary.Owners should keep comprehensive documentation, including manuals, wiring diagrams, and installation records.
Insurance and Documentation
Owners must inform insurers before installation and ensure compliance with policy conditions.Maintaining an evidence pack with all relevant data supports claims, resale, and troubleshooting.
 

Which shows what happens when you shorten something and remove the crucial details and caveats -- presumably like Nick was thinking... 😉

 

The document first release -- this one -- had to be drafted by a group of "experts" because even that took long enough, trying to bring in the whole of the boating  community at the start would mean it wouldn't have emerged until at least next year -- never mind that a lot of boaters have strong opinions about LFP which are frankly not backed up by knowledge, as any online discussion shows... 🙂

 

(but any genuinely useful/helpful feedback/ criticism will of course be listened to, that's how documents like this get improved over time)

 

The big issues now remaining are what a "competent person" means (no real standards, no training courses, no certification...) and how to not competely shut out (the few?) DIY installers who *are* competent -- always remembering that the ABC dayboat was a professional installation... 😞

1 hour ago, Jen-in-Wellies said:

I'd recently moved the Li batt from the cabin to the engine hole in anticipation of this sort of thing. Nothing in there that is a huge surprise. We've had a lot of spoilers while it was being drafted!

 Builders are still building with domestic Lithium batteries inside the cabin. I imagine there’s lots of boats out there with this set up.

 I remember years ago when people first started fitting them and everyone said you can’t fit them in engine bays as it was too cold for Lithium batteries. All confusing.

10 minutes ago, IanD said:

Which shows what happens when you shorten something and remove the crucial details and caveats -- presumably like Nick was thinking... 😉

 

The document first release -- this one -- had to be drafted by a group of "experts" because even that took long enough, trying to bring in the whole of the boating  community at the start would mean it wouldn't have emerged until at least next year -- never mind that a lot of boaters have strong opinions about LFP which are frankly not backed up by knowledge, as any online discussion shows... 🙂

 

(but any genuinely useful/helpful feedback/ criticism will of course be listened to, that's how documents like this get improved over time)

 

The big issues now remaining are what a "competent person" means (no real standards, no training courses, no certification...) and how to not competely shut out (the few?) DIY installers who *are* competent -- always remembering that the ABC dayboat was a professional installation... 😞

All good common sense advice, all I’m concerned about is that people start reading it and take it as requirement’s. 
 Will it have any legality in the future or will it be recommendations/good practice only and not requirements.

 Are people pushing for it to be requirements for the RCR/BSS?

Edited August 9Aug 9 by BoatingLifeUpNorth2

37 minutes ago, BoatingLifeUpNorth2 said:

Who exactly are the “Joint Battery Safety group” have they any Government, Health & Safety regulator powers or authority?

 Any link to their website or to any info to what makes them an authority on this matter. As it says boaters with LFP batteries and hybrid boats. I thought the builders fitting and installing these boats would have been better equipped to advise, than someone that’s just bought a boat with no experience of fitting a Lithium system unlike the installers.

As I thought it said, they are a group of people knowledgeable on the subject which was jointly set up by the IWA and CA to advise their members on this issue, they have no regulatory powers -- which is why it's a "Guidance Note" to try and help boaters, not a set of legally binding regulations which are probably years away.

 

Several external "industry experts" (e.g. ones installing and doing LFP system fitouts) were consulted and approved the document, and indeed suggested some changes which were incorporated.

 

The reason for doing this is that to put it bluntly nobody else was doing it, and without it there will not only be more and more badly-implemented (and possibly unsafe) LFP installations but a shower of inconsistent/pointless/stupid (take your pick!) rules starting to appear from insurers who are ignorant of the facts and refuse to talk to each other... 😞

 

For example one set of rules suggested elsewhere (NZ?) wass that batteries should be in a box proof against a major lithium battery fire for 30mins and automatic lithium fire extinguishers must be fitted, as well as independent power for safety-critical boat circuits if the BMS does a disconnect... 😞

 

32 minutes ago, BoatingLifeUpNorth2 said:

 Builders are still building with domestic Lithium batteries inside the cabin. I imagine there’s lots of boats out there with this set up.

 I remember years ago when people first started fitting them and everyone said you can’t fit them in engine bays as it was too cold for Lithium batteries. All confusing.

All good common sense advice, all I’m concerned about is that people start reading it and take it as requirement’s. 
 Will it have any legality in the future or will it be recommendations/good practice only and not requirements.

 Are people pushing for it to be requirements for the RCR/BSS?

Yes they are, and that is likely to become a problem for those boats in future -- as I pointed out in my first post, because it's likely that insurers will object to this long before any regulations like BSS/RCR come into effect.

 

That concern is valid but I can't see any way round it, the document clearly says that this is recommendations about "best practice" and does *not* dictate what should/must be done. The alternative was to do nothing and let boaters and insurers make bad decisions... 😞 

 

Nobody is *pushing* for it to be made into requirements for RCR/BSS but those organisations are going to have to do *something* to address this issue, they've been effectively ignoring it for years but the ABC dayboat incident -- which we *still* don't know the cause of! -- has geed things up, just like it did with insurers.

 

BSS have said they do *not* want to make a knee-jerk decision which later turns out to be wrong -- and this is unlikely now, not least because the BSS technical committee dealing with this area shares some members with the group who wrote the Guidance Note... 😉 

 

There will certainly have to be *some" rules about LFP installs on inland waterways boats in the future just like there are today for LA batteries and LPG -- part of the purpose of the Guidance Note is to try and influence the rule-writers to make sure the rules are sensible and only what is really needed for safety, not rigorous ones suitable for a 100-passenger electric ferry which would make installations on inland waterways boats effectively impossible... 🙂 

 

But in the short-term it is also hoped that this will lead to consistent and sensible rules from insurers, which is definitely not the case at the moment -- because these can come into effect immediately rather than with several years of delay... 😞 

 

(see unattended charging, "lithium" fire extinguishers...)

Edited August 9Aug 9 by IanD

21 minutes ago, IanD said:

As I thought it said, they are a group of people knowledgeable on the subject which was jointly set up by the IWA and CA to advise their members on this issue, they have no regulatory powers -- which is why it's a "Guidance Note" to try and help boaters, not a set of legally binding regulations which are probably years away.

 

Several external "industry experts" (e.g. ones installing and doing LFP system fitouts) were consulted and approved the document, amd indeed suggested some changes which were incorporated.

 

The reason for doing this is that to put it bluntly nobody else was doing it, and without it there will not only be more and more badly-implemented (and possibly unsafe) LFP installations but a shower of inconsistent/pointless/stupid (take your pick!) rules starting to appear from insurers who are ignorant of the facts and refuse to talk to each other... 😞

 

For example one set of rules suggested elsewhere is that batteries should be in a box proof against a major lithium battery fire for 30mins and automatic lithium fire extinguishers must be fitted, as well as independent power for safety-critical boat circuits if the BMS does a disconnect... 😞

You can see the problems the drafting of this by a group of knowledgeable people could cause, when boaters have Lithium systems fitted inside their living space, fitted by  "industry experts" (e.g. ones installing and doing LFP system fitouts) and that are still being fitted. As you mentioned with posts on Facebook showing them.

 I think the emphasis has to be put on “Guidelines” to not cause too much worry to boaters that have had these systems fitted.

 

 

2 minutes ago, BoatingLifeUpNorth2 said:

I think the emphasis has to be put on “Guidelines” to not cause too much worry to boaters that have had these systems fitted.

 

I believe this document is to give a 'skeleton requirement' for the insurance industry and the BSS, once they become 'requirements' to be able to obtain insurance / licence , it will no doubt be required retrospectively.

 

Hence, builders / DIYers would do well to take this as 'requirements' from now.

1 minute ago, BoatingLifeUpNorth2 said:

You can see the problems the drafting of this by a group of knowledgeable people could cause, when boaters have Lithium systems fitted inside their living space, fitted by  "industry experts" (e.g. ones installing and doing LFP system fitouts) and that are still being fitted. As you mentioned with posts on Facebook showing them.

 I think the emphasis has to be put on “Guidelines” to not cause too much worry to boaters that have had these systems fitted.

 

Who else do you think could produce such a note then? Many of the people with the best knowledge about LFP installs are -- well, LFP installers... 😉 

 

(some of who are still doing installs with LFP inside the boat, as I've pointed out -- I know Ed Shiers at Four Counties is concerned about this problem, and what this will mean for the boats in future)

 

None of the people involved have any axe to grind as far as I know, in the sensed of profiting in any way from the advice given.

 

The last part is correct for the time being -- there is obviously not a huge safety problem (though then there was the ABC dayboat...) but apart from safety they *should* be concerned about what might happen regarding insurance in the future. That is why the advice is *not* to install LFP in the living space any more, even though it used to be thought this was OK... 😞 

3 minutes ago, IanD said:

there is obviously not a huge safety problem (though then there was the ABC dayboat...)

 

The real world evidence, in terms of blown up boats, suggests that amateur installs are safer than professional ones and insurance actuaries should take note. 😁

1 hour ago, Alan de Enfield said:

 

I believe this document is to give a 'skeleton requirement' for the insurance industry and the BSS, once they become 'requirements' to be able to obtain insurance / licence , it will no doubt be required retrospectively.

 

Hence, builders / DIYers would do well to take this as 'requirements' from now.

There's no way to predict what will be *required* by regulations in the future, but AFAIK everything in the document is "sensible" advice, and deliberately does not specify things like exact building requirements or required fire precautions because what is necessary in a given case is the decision of the installer.

 

The ISO regulations say exactly the same, that there cannot be any "one-size-fits-all" rules because of the wide variation in systems and circumstances, and that it's the responsibility of the installer to make sure the system is safe.

 

That's why the Guidance Note is written as advice to the boater to help make sure the installer has got it right and not missed anything important. If the boater is the installer (i.e. DIY) then the question of competence obviously rears its ugly head... 😉 

 

(as it does even for a professional installer, see ABC dayboat...)

 

Installing LFP batteries inside the boat will be fine (now and in future) so long as they're in a box which is sealed from the living space and vented to the outside. Having them just sitting in a corner of the saloon (or under the bed...) is unlikely to be seen as acceptable in future... 😞 

Edited August 9Aug 9 by IanD

I am somewhat surprised that this guidance appears to apply only to domestic LFP batteries not propulsion batteries.

My domestic battery is LA and my propulsion battery is LFP.

This is probably an unusual case, when I did the conversion the 12V domestic system was working fine so I just left it.

 

20 minutes ago, Jen-in-Wellies said:

 

The real world evidence, in terms of blown up boats, suggests that amateur installs are safer than professional ones and insurance actuaries should take note. 😁

As I've pointed out (similarly tongue-in-cheek) many times... 😉 

The problem is that insurers do not look on DIY installations of even potentially safety-critical kit favourably -- and as I'm sure you know, statistically speaking one blown-up boat doesn't prove anything except what *can* go wrong and how severe the consequences are, certainly as bad as or worse than a gas explosion.

 

So insurers (and regulators) are likely to cast a similarly jaundiced eye on DIY LFP installs as they do to DIY LPG installations -- which funnily enough doesn't seem to cause such a big problem with most boaters.

 

The problem is that by definition "professionals" are *supposed* to know what they're doing, and as well as training will at least have their own liability insurance -- with DIY installers there's no way to distinguish between the knowledgeable like @nicknorman and the Dunning-Krueger YouTube-educated hack-it-together-and-hope merchants who post on FB... 😞 

 

11 minutes ago, Sailbadthesinner said:

I am somewhat surprised that this guidance appears to apply only to domestic LFP batteries not propulsion batteries.

My domestic battery is LA and my propulsion battery is LFP.

This is probably an unusual case, when I did the conversion the 12V domestic system was working fine so I just left it.

 

It was deliberately targeted at domestic LFP installs because there are many *many* times more of these than propulsion installations -- and most domestic LFP are probably DIY today, but most propulsion LFP are professionally installed.

 

Given that the components are the same, you'd have to be pretty dumb to think that the same advice wouldn't apply to LFP propulsion batteries -- or system, to be more correct... 😉 

 

(at the last moment I did actually suggest removing "Domestic" from the title and adding a note that the advice would also apply to LFP propulsion, but the decision was taken for this version to leave it as it was)

Edited August 9Aug 9 by IanD

Do some lithium batteries have vents in them then? If they don’t what’s the point of them venting outside. Surely it’s a bit late if the battery case has split and it’s emitting gas. Shouldn’t the BMS have cut it off before that? 
(Asking for a friend who’s not an expert in this ) 

5 minutes ago, Chris John said:

Do some lithium batteries have vents in them then? If they don’t what’s the point of them venting outside. Surely it’s a bit late if the battery case has split and it’s emitting gas. Shouldn’t the BMS have cut it off before that? 
(Asking for a friend who’s not an expert in this ) 

The cells usually have structures that vent at a set overpressure, so the cell should not split. However, it is the volume of gas that can be released and the risk of it forming an explosive mix in the space where the batt is that is the problem. Hence a ventilated space, outside the occupied cabin. A BMS is a single point of failure. A FET failing closed circuit, for example, could lead to cells continuing to receive chaege, when the BMS tries to disconnect. Hence there should be integration with charging sources to stop charging, before the BMS has to disconnect. 

1 minute ago, Jen-in-Wellies said:

The cells usually have structures that vent at a set overpressure, so the cell should not split. However, it is the volume of gas that can be released and the risk of it forming an explosive mix in the space where the batt is that is the problem. Hence a ventilated space, outside the occupied cabin. 

But to vent the case of the battery has to split open ?