How to make LifePo4 "safer" ?

I currently use Deep-Cycle lead acid battery(12v-100AH) with my small Off-grid solar system, but since it's(Battery) capacity has dropped significantly after using only for a 1 year, thinking of switching to a LifePo4 pack (since I don't like to buy a new battery each year).
But the problem is I don't have a separate shed/room (with ALL flammable stuff removed) like all others do to mitigate the risks associated with Lithium batteries.
I can keep the battery away from any bed rooms. But still inside the house.
[Also LTO is too expensive for me and NOT readily available in my country]

I know LifePO4 is significantly safer than it's predecessors, but still posses a risk.
Could you kindly please weigh in on my below intended approaches to make it safer.
Are they all (or some) useless ? Should I avoid LifePO4 ? What would you do if you were me ?

- This will only be a low powered (24v 100AH) battery
- JK BMS used
- Prismatic A grade Lifepo4 cells used from a reputed brand (e.g. EVE) with QR codes verified.
- Intending to use 2 or 4 "Fireproof RC Model Lipo Battery Safety Protective Storage Case Explosion Proof Box", with only 4 or 2 cells in one box(as per the ad - box is produced with thick, high-strength Q235 carbon steel). With cells compressed with a non-conductive ABS sheet in between the cells.

- Cells will NOT directly contact metallic box (a non-conductive ABS material placed in between cells and the box)
- I can additionally put each box again inside separate Lipo Safety Bags(or place Cells inside the Lipo bag and then place the Lipo bag inside the above metallic box). [Don't know if Lipo safe bag is of any use in LifePO4 context]
- All of above placed in a metallic Battery cabinet
- I can cover the battery cabinet with a fire blanket.
- [Optionally - not sure if this is feasible] Add independent(from BMS) temperature sensor to each cell (either to alarm and/or automatically cut-off the battery if at least one sensor detects a temp rise. It will be powered(or at least started) by a different smaller pow supply).
- Not sure about the strength of the above metallic box since it did NOT arrive yet, but if it is strong enough I can keep a plastic sand bag on top of each box.
- Keep 1 or 2 , Auto fire Extinguishers balls inside the battery cabinet. I saw YT videos saying they don't work and only the large sound they make is useful.
[This brand is NOT available for purchase in my country unfortunately => Saw this YT video showing a Auto Fire Extinguishers(Fire ball) extinguishing a Lithium fire (but NOT much details available)- ]

At last, keep Gas masks enough for every one in the house, if all above fails (since LifePO4 fumes are said to be toxic) + Fire extinguisher.

You could put your batteries, inverter and other parts in a separate shed. As an added bonus, this would remove the noise from the fans from the house at the same time.

You’re way overthinking this. Gas masks? Lifepo4 is just as safe as lead, especially AGM batteries. For a simple 24 volt 100ah battery, you’re probably better off just getting a commercially built unit and be done with it.

akumd said:

At last, keep Gas masks enough for every one in the house,

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Never heard of this. What type of mask? The masks I use don’t filter out smoke,

akumd said:

plastic sand bag on top of each box

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I’ve filled a few sandbags and would not want these above my batteries.

Very heavy and after time they leak.

akumd said:

Should I avoid LifePO4 ? What would you do if you were me ?

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i would figure out why the lead acid batteries only last a year. My guess is the system is not big enough.

akumd said:

Intending to use 2 or 4 "Fireproof RC Model Lipo Battery Safety Protective Storage Case Explosion Proof Box", with only 4 or 2 cells in one box(as per the ad - box is produced with thick, high-strength Q235 carbon steel). With cells compressed with a non-conductive ABS sheet in between the cells.

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These look like ammo cans.

Thanks all who responded.

Bongbong said:

You could put your batteries, inverter and other parts in a separate shed. As an added bonus, this would remove the noise from the fans from the house at the same time.

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@Bongbong , I would have to build a new shed from scratch for this. Which is a big task.

Brett V said:

You’re way overthinking this. Gas masks? Lifepo4 is just as safe as lead, especially AGM batteries. For a simple 24 volt 100ah battery, you’re probably better off just getting a commercially built unit and be done with it.

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@Brett V , I already keep the 12v-100AH Deep cycle battery in my house. Do you think both these posses (approximately) same level of risks ?

I'd consider LiFePo4 quite safe.

@chrisski , thanks.

Never heard of this. What type of mask?
ones used for painting (which covers eyes and mouth with filters). I think they provide some safety for toxicity of paint.
May be they are not much effective for a Lifepo4 fume toxicity level. But I thought they might provide sufficient safety for ppl to run out of the house in case of a Lithium smoke.


I’ve filled a few sandbags and would not want these above my batteries.
Yes you might be correct. Unfortunately things like Cellblock FCS is NOT available in my country.

i would figure out why the lead acid batteries only last a year. My guess is the system is not big enough.
Currently I use a 550W Trina panel, with a MPPT SCC(Hybrid offgrid inverter - UTL). My usual use was less than 200W and rarely reached 220W. I live in a tropical country (Sri Lanka) with sun light from 8AM to 4PM, usually. But some days are cloudy (my guess was such days resulted in higher cycle count). Unlike BMS used for Lithium, for Lead-Acid there is no way to measure cycle count right ?
Also my charge current was 15A and (later)18A (according to the Battery spec can use 0.1C to 0.25C - i.e. 10A to 25A for charging). Was this too much ?
(with the 24v-100AH LifePo4 my plan was to add a 605W panel(in series - curr. rating do match) and increase day time use till about 400-500W).

How do you propose I can improve the system such that a Deep-cycle Lead acid can be used for a longer time ?

shadowmaker said:

I'd consider LiFePo4 quite safe.

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@shadowmaker, yes, that is what I have heard too (and hoping to be true ). But the emitted smoke is highly toxic. Also saw at least 2 cases of LifePO4 explosions(not severe as NMC still) in this forum.
Also in below video, he does NOT provide a video demo, but raises the point that, all of LifePO4 safe demos are done with one Cell and in open air. According to him, trouble occurs when multiple cells present in a confined space. I could not find a test done in a confined space, yet.

Also in below video, there is a flame (not nearly as NMC level)

akumd said:

Thanks all who responded.

@Bongbong , I would have to build a new shed from scratch for this. Which is a big task.



@Brett V , I already keep the 12v-100AH Deep cycle battery in my house. Do you think both these posses (approximately) same level of risks ?

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No, I’d say the LFP is safer than the lead acid battery.

To make them safer ensure all your connections are done properly and that good components are used. I would rate the relative fire risk higher for batteries in your hand held devices. Also many kitchen appliances pose higher fire risk either from poor construction or through misuse. It is rather amazing how many grease fires happen.

One thing you can look into is a fire suppression blanket. Also a good idea to have a CO detector and also a smoke alarm installed near the batteries.

Mattb4 said:

To make them safer ensure all your connections are done properly and that good components are used.

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I agree, the biggest risk is connections and inadequate over current protection not the LiFePO4 batteries.

akumd said:

@shadowmaker, yes, that is what I have heard too (and hoping to be true ). But the emitted smoke is highly toxic. Also saw at least 2 cases of LifePO4 explosions(not severe as NMC still) in this forum.
Also in below video, he does NOT provide a video demo, but raises the point that, all of LifePO4 safe demos are done with one Cell and in open air. According to him, trouble occurs when multiple cells present in a confined space. I could not find a test done in a confined space, yet.

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They do say that white smoke coming from LFP cell is toxic/highly toxic, but then what smoke isn't? Smoke detector operated fan ventilating outside might be cure for that. For punctures, just don't allow any crowbars in the same room with your batteries...

Mattb4 said:

To make them safer ensure all your connections are done properly and that good components are used. I would rate the relative fire risk higher for batteries in your hand held devices.

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THIS.

1. There is probably a far greater chance of any DIY solar system generating a regular electrical (wiring) fire than a battery chemical fire so this should remain the primary concern. This includes BMS equipment and wiring. And this includes internal wiring to inverters and charge controllers.

2. I added a passive vent system that would allow gases to escape outdoors if a cell vented. I made the vent vent out of 4" aluminum dryer duct.

#2 Puts me in the paranoid category on this forum, but I can tell you I am still more worried about my charge controller catching fire. The charge controller is the only non-lug DC terminal in my system, and charge controllers are known for catching on fire internally.

akumd said:

Thanks all who responded.

@Bongbong , I would have to build a new shed from scratch for this. Which is a big task.



@Brett V , I already keep the 12v-100AH Deep cycle battery in my house. Do you think both these posses (approximately) same level of risks ?

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I don't know how your house looks, I think it will be simpler to just put your batteries against an outside wall of your house and build a simple cabinet around it if needed.. Eliminates concerns about fumes inside the house, etc.

hwy17 said:

...

2. I added a passive vent system that would allow gases to escape outdoors if a cell vented. I made the vent vent out of 4" aluminum dryer duct.

...

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My batteries are right below a 3X3 sliding window. Might prove difficult to open if a big fire happened but it could be broken fairly easy if required to vent smoke. Maybe I need to install a sign, "Break glass in case of Fire".

as suggested below, ventilation duct seems a good idea,

shadowmaker said:

They do say that white smoke coming from LFP cell is toxic/highly toxic, but then what smoke isn't? Smoke detector operated fan ventilating outside might be cure for that. For punctures, just don't allow any crowbars in the same room with your batteries...


THIS.

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hwy17 said:

1. There is probably a far greater chance of any DIY solar system generating a regular electrical (wiring) fire than a battery chemical fire so this should remain the primary concern. This includes BMS equipment and wiring. And this includes internal wiring to inverters and charge controllers.

2. I added a passive vent system that would allow gases to escape outdoors if a cell vented. I made the vent vent out of 4" aluminum dryer duct.

#2 Puts me in the paranoid category on this forum, but I can tell you I am still more worried about my charge controller catching fire. The charge controller is the only non-lug DC terminal in my system, and charge controllers are known for catching on fire internally.

Click to expand...

akumd said:

as suggested below, ventilation duct seems a good idea,

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I used this (car part):


With this (dryer duct):


They are not guaranteed compatible diameters, but with mine turned out the rigid collar on the dryer duct vent just barely fit over that flange with force, so they made a perfect interference fit. They could probably also be used with flexible semi rigid aluminum duct for a longer run. But I don't know that the semi rigid would definitely fit well with the Spectre, again because it's a car part.

Brett V said:

No, I’d say the LFP is safer than the lead acid battery.

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@Brett V , komoai (it doesn't need any registration and I don't have a chat GPT account yet,) seems to agree with you.

Hoping others are NOT disagreeing with this statement ("LFP is safer than the lead acid battery.").

hwy17 said:

I used this (car part):

https://www.amazon.com/Spectre-Performance-Aluminum-Intake-Mounting/dp/B005M1ZUWK/

With this (dryer duct):

Aluminum 4 in. Air tight pipe and dryer vent Hood ATDAVHA4/12 - The Home Depot

The 4 in. Aluminum Dryer Vent Hood, Pipe and Collar is suitable for venting a dryer or bathroom. This fireproof ventilation accessory is made from aluminum and features a positive-action vent closure that promotes optimum efficiency. Uses our proprietary Air Tight technology to reduce air...

www.homedepot.com

They are not guaranteed compatible diameters, but with mine turned out the rigid collar on the dryer duct vent just barely fit over that flange with force, so they made a perfect interference fit. They could probably also be used with flexible semi rigid aluminum duct for a longer run. But I don't know that the semi rigid would definitely fit well with the Spectre, again because it's a car part.

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@hwy17, do you use a ventilation fan too ?

akumd said:

But the problem is I don't have a separate shed/room (with ALL flammable stuff removed) like all others do to mitigate the risks associated with Lithium batteries.

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I think as mentioned, most people that isolate their solar system do so because of the chance of a regular electric fire, which is way more likely.

I'm not saying you're being overkill with isolating the battery in a box and such, any layers of safety you can add are obviously good... However, I think it's much more likely that a charge controller, bad connection, user error, accidentally bridging something, etc., ends up being the cause of a potential fire.

Haven't seen any threads here with the ultimate determination of "my LiFePO4 battery spontaneously combusted and burned everything down!" - But I've seen a lot of these that had stupid user errors like LiFePO4 cells on a metal shelf with a bunch of alligator clips everywhere, or cells on a piece of plywood with no structural support that collapsed. Stuff like that is WAY more likely to cause a fire.

hwy17 said:

The charge controller is the only non-lug DC terminal in my system

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Really, really hate screw-in terminals that just bite onto the wire. Really wish everyone just standardized on giving you a terminal to mount a lug on. I trust a properly crimped lug & wire to not separate way more than I do these little screw-in terminals that are common on charge controllers...