Hi Graham,

Without wanting to interrogate the author...

The PAS document requires all indoor locations which contain storage batteries to be ventilated to outdoors (6.5.4) and refers to BS EN IEC 62485 for further information. This does not account for various battery compositions - particularly lithium iron phosphate. There is no direct reference to a baseline ventilation rate (62485 has a calc but it's based on older battery chemestry).

Presumably we can take a sensible approach here and follow battery manufacturer's guidance/recommendations with regard to the provision and rate of ventilation?

Regards,

Peter

And if you're aiming for PassivHaus (or even generally good thermal performance), you need air tightness, so the last thing you want is uncontrolled holes in the walls.

Caravans etc have had this problem for while (most incorporate "leisure batteries") - solutions vary from a compartment only accessible from outside to a interior box with a small plastic tube to outdoors (I've no idea how effective that might be in practice). Usually lead acid, so Hydrogen is reasonably likely.

   - Andy.

An alternative may be  to have an explosion release membrane to the outside of the house, rather like the 'tear here' deliberately weakened walls and roof designs one sees on larger substation buildings and ammunition dumps and so forth. ;-)

Joking aside,one has to be clear as to the purpose of the ventilation,  the removal of heat can safely be into the house, but the removal of Hydrogen or worse a hydrogen oxygen mix rapidly becomes a serious matter requiring dilution to outside.

Equally for a well functioning lithium battery there is no gas production that vents most of the time, and if it ever it does, you may well have another problem as well namely a serious fire...

This (US) video compares shooting a rifle slug at a primary cell, a modest Lithium Ion battery (2590 prismatic size) and a zinc air cell. https://www.youtube.com/watch?v=PO8Nu3F8mkA

The 2590s are used a lot in the manpack radios, which is sobering,

Mike

pww235 said:

Presumably we can take a sensible approach here and follow battery manufacturer's guidance/recommendations with regard to the provision and rate of ventilation?

Those recommendations would generally be for "normal use" condition and foreseeable fault, and possibly not consider the battery as a victim of fire itself?

pww235 said:

This does not account for various battery compositions - particularly lithium iron phosphate. 

Are they not covered in BS EN IEC 62485-5 ?

Clause 7.3 of that standard clearly says that harmful gases can be produced and contains requirements to help stop the production of those from the BMS - but that doesn't take into account that the battery might itself be a victim of fire, even though the Scope of the standard says it covers private residences.

Having said that, there's a whole list of stuff in Clause 9.1 of BS EN IEC 62485-5 that needs to be taken into account, and ventilation is needed (if a battery is installed at home) to help address BS EN IEC 62485-5:2021 Clause 9.1 b).

Have people seen the post on linkedin by GivEnergy?  Titled

 Industry update 

Stating things like

Away from the PAS and in terms of safety, you can absolutely install GivEnergy LiFePO4 batteries in lofts where appropriate siting, lifting, access and regulations are considered and historic installations are not affected.

This COULD confuse people like when people were advised to fit a Zappi with only an MCB

I saw that too. Crazy to dismiss safety based guidance because it doesn't suit. 

I noticed they claim to be getting BSI to rework their regs too

to balance things out they should also llink to this presentation. The adverts are a pest, but the talk, and some of the images, should be sobering stuff for the 'have a go'  merchants.

Mike

to balance things out they should also llink to this presentation. The adverts are a pest, but the talk, and some of the images, should be sobering stuff for the 'have a go'  merchants.

Mike

Wow, really interesting video. Ive never installed a Lithium ion battery in a dwelling.

Im shocked that we allow the sale of electric light vehicles using batteries based on Lithium ion chemistry. 

For some balance you should watch the following video which includes tests on LifePO4 batteries. The battery chemistry of most leading domestic ESS providers.

https://youtu.be/Qzt9RZ0FQyM?si=4qcPtXdFwJIazArL

Im shocked that we allow the sale of electric light vehicles using batteries based on Lithium ion chemistry. 

New things don't necessarily have to be totally safe - no worse than what they replace will often do.

Given the risks of carrying tens of litres of petrol around (and many instances of ICE engine fires from just driving along the motorway - no need for any impact damage) and the likes of the Liverpool multi-storey car park fire (started by an ICE Landrover apparently), in a way society could "afford" quite a few serious incidents and sill be in a better position.

  - Andy.

DA said:

ironically in an “cold roof” attic space

ironically, not all year round !

DA said:

battery would be well ventilated by natural airflow

Independent of battery chemistry, but venitlation as someone said, possibly too close to windows with some heavier than air gases and vapoirt - not all flammable?

DA said:

Also ironically, the battery is less likely to suffer impact damage in this less frequented space.

A fair point, and something to consider before locating a battery near a garage door, for example. And of course relevant to all battery chemistries, but there are other locations that can be "less frequented" ?

DA said:

For some balance you should watch the following video which includes tests on LifePO4 batteries. The battery chemistry of most leading domestic ESS providers.

In making that statement, you appear to believe that LifePO4 was ignored in the development of the PAS, and requires some "special treatment", yet I have posted above the "not in loft" being the contentious issue is actually independent of battery chemistry.

I'm not sure how many times I must repeat that, and I guess people will hear and see exactly what they want to?

Should we not consider the installation of batteries within fire-resistant, dedicated outdoor enclosures? Also within the enclosure include for integrated climate control system for optimal operating conditions.

AMK said:

Should we not consider the installation of batteries within fire-resistant, dedicated outdoor enclosures?

That is, effectively the preference of PAS 63100 - outdoor (enclosure or outbuilding).

When one wishes to build an attached garage to a dwelling, even one that is in practice too narrow, and will only store household tools, building control get involved and require windows to be removed, plumbing and so forth to be fire-stopped, and if you are building a habitable room above it then fire resistant ceiling materials. In effect the garage is to be built as if not only is there a car within it, but that the car will be on fire. It is not totally clear why such an approach does not extend to the construction of kitchens, as there are far more domestic fires started there, but that is an aside.

It strikes me a similar designed in approach will eventually be needed for battery systems, at least larger ones. The problem is there will a great many existing properties, where such an addition is simply not possible.

I am currently in a South American country with far fewer heath and safety scruples as the UK, and as the water supply is intermittent, it is common to have a tank on the roof for the inevitable water cut.

Maybe a similar approach could be adopted in the UK for the sort of thing we are considering. Perhaps the more 'uptown' version,.

In the UK such a thing would almost always need planning consent, but here it does not.

The 3 lines in the foreground under my window are 13.8kV between phases for those curious. Did I mention the lack of an H and S culture. ?!

Mike

Mike

mapj1 said:

It strikes me a similar designed in approach will eventually be needed for battery systems, at least larger ones.

Are there not requirements for LPG and other fuel storage?

gkenyon said:

ironically, not all year round !

I was referring to the insulation construction method being “cold roof” and therefore ventilated rather than a “warm roof”, not the ambient temperature. It was meant to be light hearted! Not a judgment on the PAS.

gkenyon said:

In making that statement, you appear to believe that LifePO4 was ignored in the development of the PAS, and requires some "special treatment"

Again, not my intention. Merely supplying balance to the shocking video posted earlier that highlights the explosive nature of lithium ion chemistry. I believe its important to highlight the facts and the differences, regardless of the PAS, as misinformation spreads easily and can have a negative PR effect for all chemistries on the market (which includes outdoor installations).

If i appear to arguing for the sake of it, I'm not. Ive installed around 50 ESS setups as per MCS/ manufacturer guidelines at the time and want to be clear in my mind about the hazzards the PAS is highlighting. I want to know that my installs are safe as I believed them to be at the time.
Currently, i feel confident that the LifePO4 chemistry’s greatest risk is toxic gas following puncture. Not fire or being the victim of fire. Though with the installation of smoke detectors this for me is similar to safeguards implemented for other appliances eg CO emissions from boilers etc.
I never implied that you hadn't considered LifePO4 chemistry during the development of the PAS. Indeed, as this was considered perhaps you can provide me with any links to data for heavier than air gas emissions for LifePO4 batteries? Im aware of it with lithium ion, but cant find it for the iron chemistry. It would be a big help.

Again my discussion is not railing against the PAS. It is what it is, and i will follow its guidance if so directed. It is simply for peace of mind! 

yes, and that is sort of my point, - but in part LPG and oil is less serious in the UK because most folk don't use it, and those that do tend to be rural where there is space for an oil or propane tank out in the yard as per HSE guidance. I suspect we would like to have solar with battery storage in more built up areas too.

If the use of bottled gas was common for example in blocks of flats in the UK, we'd find we had calor gas bottles in the kitchen of each flat, indeed, where I am staying right now, they do just that link, and although it sounds and looks horrific,  in practice it is not a major cause of accidents.

My point is that we need to modify how we design new buildings, and probably become quite creative and much less fuddy duddy with what we allow to be done in and on existing ones.

M

DA said:

construction method being “cold roof” and therefore ventilated rather than a “warm roof”,

OK, but my "cold roof" 100 % definitely isn't that cold for quite a chunk of the year.

DA said:

It was meant to be light hearted!

OK, but this topic is being taken very seriously in the industry ... and quite rightly so.

DA said:

If i appear to arguing for the sake of it, I'm not. Ive installed around 50 ESS setups as per MCS/ manufacturer guidelines at the time and want to be clear in my mind about the hazzards the PAS is highlighting. I want to know that my installs are safe as I believed them to be at the time.

I understand this. There was ample opportunity to be involved earlier.
No-one is saying the standard is retrospective ... and I'm not going to pass judgement on installs I've not seen.

However, the plain fact of the matter is that most of the discussion is around "not in the loft".

This misses, by more than a Nautical Mile, the issue that the PAS says, first and foremost, and wholly divorced from battery chemistry ...  "Outdoors please ... unless it's not practicable".

That doesn't mean "the battery I have in stock isn't suitable for outdoor use so it's impracticable" ... but that if at all possible, you should select an appropriate battery and install it somewhere other than the  inhabitable parts of the premises or their immediate vicinity.

Given that, the argument over "loft or not" is rather academic, don't you think?