How to make LifePo4 "safer" ?

[hwy17]

@hwy17, do you use a ventilation fan too ?

No, my battery box is semi-sealed, it's a truck "underbody box" so it has weatherstripping.

So I am relying on the pressure generated by the venting cell to expel the gases, I don't mind if the box remains filled with gas, I just want the bulk of it outside so it does not fill up the room.

My box has air leaks for sure though, so the venting would need to be quite spectacular like PSSSHHHHHH for it to work, for pressure to drive itself out the dryer vent. If a cell started slowly leaking pspspsssssssss, it would probably all just leak out of the box indoors.

 

[hwy17]

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...

Yeah I've come to the charge controller last in my build and it's really frustrating me. Like I'm seriously considering some kind of lug mod if I can come up with one, after I get it set up first to confirm my CC isn't DOA or anything.

 

[Brett V]

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...

That’s why you use ferrules

 

[hwy17]

That’s why you use ferrules

But then you have the complication about whether the manufacturer recommends ferrules or not. For North American equipment, it's usually not included in the instructions and would be an off label use.

Phoenix contact makes the 2 awg terminal on my CC

Phoenix contact makes 2 awg ferrules:

https://www.digikey.com/en/products/detail/phoenix-contact/3201495/2424623

But my manual does not say to use them. I haven't decided if I think I know better.

 

[robbob2112]

WARNING - Chatgpt answers below - but they do align with other research I have done on th subject

Q - What gasses are generate when a LiFePO4 battery vents?

A -
When a LiFePO4 (Lithium Iron Phosphate) battery vents, it typically releases a mixture of gases. These gases can include:

1. **Carbon Dioxide (CO2):** A common byproduct of the chemical reactions occurring within the battery.

2. **Carbon Monoxide (CO):** Can be produced in small amounts, especially if the battery is overheating or if there is a short circuit.

3. **Hydrogen (H2):** May be released if the battery's electrolyte decomposes.

4. **Phosphorus Oxyfluoride (POF3):** Can be produced if the battery's phosphate-based cathode material decomposes.

5. **Lithium Fluoride (LiF):** May be formed and released as a gas or vapor, particularly if the battery is subjected to extreme abuse conditions.

6. **Various Organic Compounds:** Depending on the specific electrolyte and binder materials used in the battery, various organic vapors can be released.

It's important to note that venting is a sign of battery failure and can pose safety risks. The gases released can be flammable, toxic, or both, so proper ventilation and safety measures should be in place when handling or using LiFePO4 batteries.


Q - how hazardous are these to humans and pets?

A -
The gases released when a LiFePO4 battery vents can be hazardous to both humans and pets, depending on the concentration and exposure duration. Here's a breakdown of the potential hazards:

1. **Carbon Dioxide (CO2):** In small amounts, CO2 is not harmful. However, in high concentrations, it can lead to respiratory distress and, in extreme cases, suffocation.

2. **Carbon Monoxide (CO):** CO is a highly toxic gas that can be lethal. It binds to hemoglobin in the blood, reducing the blood's ability to carry oxygen. Exposure can lead to headaches, dizziness, nausea, confusion, and in severe cases, death.

3. **Hydrogen (H2):** Hydrogen is not toxic, but it is highly flammable. Accumulation of hydrogen gas can create an explosion risk if ignited.

4. **Phosphorus Oxyfluoride (POF3):** This is a toxic and corrosive gas. Inhalation can cause respiratory irritation, coughing, and shortness of breath. Long-term exposure can lead to more severe respiratory problems.

5. **Lithium Fluoride (LiF):** While not typically a major concern in its gaseous form, any particulate matter from LiF can irritate the respiratory system if inhaled.

6. **Various Organic Compounds:** The toxicity of these compounds varies depending on their specific nature. Some may cause irritation of the eyes, skin, and respiratory system, while others could have more severe toxic effects.

To minimize risks, it's crucial to handle LiFePO4 batteries according to manufacturer guidelines and to ensure proper ventilation in areas where batteries are used or stored. In the event of battery venting, evacuate the area and seek fresh air immediately. If symptoms of exposure occur, seek medical attention promptly.

 

[robbob2112]

But then you have the complication about whether the manufacturer recommends ferrules or not. For North American equipment, it's usually not included in the instructions and would be an off label use.

Phoenix contact makes the 2 awg terminal on my CC

Phoenix contact makes 2 awg ferrules:

https://www.digikey.com/en/products/detail/phoenix-contact/3201495/2424623

But my manual does not say to use them. I haven't decided if I think I know better.

Ferrule use really depends on the design of the screw terminal.

Those with a screw that pushes down a cup shaped wedge always use bare wire. The cup shaped wedge gathers the wires and pushes evenly without letting them be damaged or slide past the slides.

Those with spring connectors all use bare wire, but not all are designed for stranded and solid. They can be designed for one or both depending on the MFG. This is the type Victron uses in the MPPT that it calls out bare stranded wire. This is also how the WAGO connectors work for solid wires except they have a leaver to press verse totally spring loaded.

The bare stranded terminal blocks go into the spring and push the spring up and contact the whole wires and then it pushes them flatter to get a larger contact spot. This type typically has a screw on the top to improve the pressure.

The ones for solid wire then to have a hook that faces the wires and bites into the wire. The bites into the wire would damage stranded but not solid.

Those with just a screw like is typically found in a breaker not designed for 2 wires is made for solid wire and it is preferable to use ferrules when using stranded wire. Note, those breakers designed for two wires have a plate it pushes down but they are still designed for solid wire so ferrules are still preferred.

Victron MPPT have both types of terminal blocks. In their manual they explicitly call out the type of wire in their equipment manuals.

 

[akumd]

@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.").
View attachment 207245

ChatGPT gives the same answer,

 

[hwy17]

Ferrule use really depends on the design of the screw terminal.

Those with a screw that pushes down a cup shaped wedge always use bare wire. The cup shaped wedge gathers the wires and pushes evenly without letting them be damaged or slide past the slides.

Those with spring connectors all use bare wire, but not all are designed for stranded and solid. They can be designed for one or both depending on the MFG. This is the type Victron uses in the MPPT that it calls out bare stranded wire. This is also how the WAGO connectors work for solid wires except they have a leaver to press verse totally spring loaded.

The bare stranded terminal blocks go into the spring and push the spring up and contact the whole wires and then it pushes them flatter to get a larger contact spot. This type typically has a screw on the top to improve the pressure.

The ones for solid wire then to have a hook that faces the wires and bites into the wire. The bites into the wire would damage stranded but not solid.

Those with just a screw like is typically found in a breaker not designed for 2 wires is made for solid wire and it is preferable to use ferrules when using stranded wire. Note, those breakers designed for two wires have a plate it pushes down but they are still designed for solid wire so ferrules are still preferred.

Victron MPPT have both types of terminal blocks. In their manual they explicitly call out the type of wire in their equipment manuals.

I think this is what I'm working with:


And I think it's just plainly not that good of a connector for a 100 amp sustained load. Fine strand wire is too likely to become loose in it and ferrules reduce the contact patch. I will probably end up going with a ferrule, and I might try using the screw terminal to sort of crush the ferrule into a form fit in place.

But I think if we looked up at the more intensely designed systems like grid scale ESS, EVs, Tesla Powerwalls, etc. we would find not one fine stranded wire ever connected to a screw down terminal in those products. I believe it's an irredeemable compromise.

 

[DBarr]

I'm fairly new at this, BUT if I were to take the sky is falling state of mind I don't believe I would have been installing a solar setup in the first place.
I have read the horror stories and watched the videos of the battery fires. That is the reason I went with NAME BRAND rack batteries like SOK and EG4. These batteries (as far as I know) haven't had and reports of fires because of regular use. Please correct me if I am wrong. I keep my batteries and charge controllers in my garage connected to my home. I check everything daily (sometimes several times a day) except when I'm away.
My belief is the LifeP04 battery is one of the safest. Again please correct me if I am wrong.
Solar since June of 2018.

 

[robbob2112]

I think this is what I'm working with:

View attachment 207284
And I think it's just plainly not that good of a connector for a 100 amp sustained load. Fine strand wire is too likely to become loose in it and ferrules reduce the contact patch. I will probably end up going with a ferrule, and I might try using the screw terminal to sort of crush the ferrule into a form fit in place.

But I think if we looked up at the more intensely designed systems like grid scale ESS, EVs, Tesla Powerwalls, etc. we would find not one fine stranded wire ever connected to a screw down terminal in those products. I believe it's an irredeemable compromise.

That sort is ideal for a ferrule using a square shape. The hex and penta shapes don't make as good a contact patch.

I forgot about that, ferrule crimpers come in different shapes and different ones are better for different terminals.

And that assumes quality ferrules that are long enough to bottom out when inserted into the terminal block and thin enough to deform when pressed in it.

I learned this one the hard way from the cheap amazon ferrules they are shorter and thicker because it is cheaper to make them that way. And if crimping a ferrule on a high amperage wire you either use a lug crimper or a ferrule crimper made for the large sized ferrules. Downside is the shape of the lug crimper may not be ideal.

 

[robbob2112]

I'm fairly new at this, BUT if I were to take the sky is falling state of mind I don't believe I would have been installing a solar setup in the first place.
I have read the horror stories and watched the videos of the battery fires. That is the reason I went with NAME BRAND rack batteries like SOK and EG4. These batteries (as far as I know) haven't had and reports of fires because of regular use. Please correct me if I am wrong. I keep my batteries and charge controllers in my garage connected to my home. I check everything daily (sometimes several times a day) except when I'm away.
My belief is the LifeP04 battery is one of the safest. Again please correct me if I am wrong.
Solar since June of 2018.

You are correct - sticking to the brand name and pre-built stuff is safer than some of the other junk. But, you still have to go back and check/retorque the bolts/screws/connections and give a tug to the wires to see if everything is secure. Preferably shut everything down before doing this since there is always a risk of shorts, shocks, or sparks if you to manage pull something loose.

And assuming the person that installed the gear did a good job on all the connections. If anything is hot when running best to shut it down and check that connection.

 

[hwy17]

That sort is ideal for a ferrule using a square shape. The hex and penta shapes don't make as good a contact patch.

I forgot about that, ferrule crimpers come in different shapes and different ones are better for different terminals.

See these sort of nuances don't strike me as appropriate for high amperage DC. Ferrules to me are something the german technician uses when he wires up the controls system on an industrial machine. Does AT&T ever use ferrules on fine strand wire in their 48v telco systems? I doubt it. Every time I see their work it's lug city.

 

[robbob2112]

See these sort of nuances don't strike me as appropriate for high amperage DC. Ferrules to me are something the german technician uses when he wires up the controls system on an industrial machine. Does AT&T ever use ferrules on fine strand wire in their 48v telco systems? I doubt it. Every time I see their work it's lug city.

Well, I haven't been in a CO battery room in years but back then it was all lugs and large cables.

And no, I don't like the ferrules much either with all the different types and chances of making a mistake. But we are left to the mercy of the vendors as long as we use their equipment. And this is another reason the knock-off relabels suck a lot of the time. No engineering goes into making the box cheaper so they tend to fail quicker or burn up and be a hazard.

I have seen some terminal block to lug converters from time to time, but I have not used them. From what I can tell it is a screw through a piece of plated copper then the strip sticks into the terminal. I can see they would work well for the straight screw type, but not for the others.

 

[tinyt]

This is what I ordered from ali...
Will find out when I use it instead of ferrules.

 

[robbob2112]

This is what I ordered from ali...
Will find out when I use it instead of ferrules.

Those may work if you use the right sized wire (should have all strands inside the loop and little to no extra space). And from the look of them the crimper should be one that presses down in the center and rolls the edges in. Watch the video in the ad. Seems like rather than just punching the middle down it should press the edges as well

I never seem to trust the quality of anything from ALIexpress personally, but hopefully they are good. Caveat - if you are doing something grid-tied and they aren't UL listed they won't pass.

 

[hwy17]

I have seen some terminal block to lug converters from time to time, but I have not used them. From what I can tell it is a screw through a piece of plated copper then the strip sticks into the terminal. I can see they would work well for the straight screw type, but not for the others.

Yeah I'm ok with it while I've got my CC under paneled, but I have thoughts about significant over paneling it in the future. If it's gonna be running floored at 100 amps I might think about attempting some kind of lug mod.

 

[Brett V]

I think this is what I'm working with:

View attachment 207284
And I think it's just plainly not that good of a connector for a 100 amp sustained load. Fine strand wire is too likely to become loose in it and ferrules reduce the contact patch. I will probably end up going with a ferrule, and I might try using the screw terminal to sort of crush the ferrule into a form fit in place.

But I think if we looked up at the more intensely designed systems like grid scale ESS, EVs, Tesla Powerwalls, etc. we would find not one fine stranded wire ever connected to a screw down terminal in those products. I believe it's an irredeemable compromise.

Yeah, that’s not the best connector but it’s what you have to work with on an increasing amount of imported gear. This article discusses square ferrule crimpers and might be worth looking in to.

Everything You Need to Know About Ferrules: A Comprehensive Guide

Ferrules come in many shapes, sizes and uses. Learn more about how ferrules are used in industrial automation to make your work safer.

library.automationdirect.com

 

[Hedges]

Code for ESS indoors allows it in closet or garage, not living area. Walls to have fire resistant materials. Smoke alarm, or for place like garage where not a listed application, heat alarm wired into home's smoke alarm system.

I think something which vents to exterior rather than interior would be good.

Make sure that a conflagration started at the batteries won't block path to exits.

I'd think you could go a bit overboard, fire rated door etc. so it was possible for battery fire to burn itself out without spreading to rest of house.

 

[robbob2112]

Code for ESS indoors allows it in closet or garage, not living area. Walls to have fire resistant materials. Smoke alarm, or for place like garage where not a listed application, heat alarm wired into home's smoke alarm system.

I think something which vents to exterior rather than interior would be good.

Make sure that a conflagration started at the batteries won't block path to exits.

I'd think you could go a bit overboard, fire rated door etc. so it was possible for battery fire to burn itself out without spreading to rest of house.

Building code in the states is for a 4 hour burn time between the garage and the living space. This means either a double layer of sheetrock of a layer of 5/8 fire rock on the wall from the floor all the way to the roof. Any penetrations must be sealed around so the fire can't follow a wire through. This also means a steel door between.

In more modern national building code there is also a requirement for a steel door with a self closing hing on it. This is a requirement that was piecemeal until about 15 years ago when it was adopted nationally.

Where I live it has been code for more than 20 years and some folks get into trouble by replacing the spring loaded hinge with a regular one and then when they sell the house they have to go back the other way or it won't pass inspection.

 

[wpns]

WARNING - Chatgpt answers below - but they do align with other research I have done on th subject

Q - What gasses are generate when a LiFePO4 battery vents?

A -
When a LiFePO4 (Lithium Iron Phosphate) battery vents, it typically releases a mixture of gases. These gases can include:

1. **Carbon Dioxide (CO2):** A common byproduct of the chemical reactions occurring within the battery.

2. **Carbon Monoxide (CO):** Can be produced in small amounts, especially if the battery is overheating or if there is a short circuit.

3. **Hydrogen (H2):** May be released if the battery's electrolyte decomposes.

4. **Phosphorus Oxyfluoride (POF3):** Can be produced if the battery's phosphate-based cathode material decomposes.

5. **Lithium Fluoride (LiF):** May be formed and released as a gas or vapor, particularly if the battery is subjected to extreme abuse conditions.

6. **Various Organic Compounds:** Depending on the specific electrolyte and binder materials used in the battery, various organic vapors can be released.

It's important to note that venting is a sign of battery failure and can pose safety risks. The gases released can be flammable, toxic, or both, so proper ventilation and safety measures should be in place when handling or using LiFePO4 batteries.


Q - how hazardous are these to humans and pets?

A -
The gases released when a LiFePO4 battery vents can be hazardous to both humans and pets, depending on the concentration and exposure duration. Here's a breakdown of the potential hazards:

1. **Carbon Dioxide (CO2):** In small amounts, CO2 is not harmful. However, in high concentrations, it can lead to respiratory distress and, in extreme cases, suffocation.

2. **Carbon Monoxide (CO):** CO is a highly toxic gas that can be lethal. It binds to hemoglobin in the blood, reducing the blood's ability to carry oxygen. Exposure can lead to headaches, dizziness, nausea, confusion, and in severe cases, death.

3. **Hydrogen (H2):** Hydrogen is not toxic, but it is highly flammable. Accumulation of hydrogen gas can create an explosion risk if ignited.

4. **Phosphorus Oxyfluoride (POF3):** This is a toxic and corrosive gas. Inhalation can cause respiratory irritation, coughing, and shortness of breath. Long-term exposure can lead to more severe respiratory problems.

5. **Lithium Fluoride (LiF):** While not typically a major concern in its gaseous form, any particulate matter from LiF can irritate the respiratory system if inhaled.

6. **Various Organic Compounds:** The toxicity of these compounds varies depending on their specific nature. Some may cause irritation of the eyes, skin, and respiratory system, while others could have more severe toxic effects.

To minimize risks, it's crucial to handle LiFePO4 batteries according to manufacturer guidelines and to ensure proper ventilation in areas where batteries are used or stored. In the event of battery venting, evacuate the area and seek fresh air immediately. If symptoms of exposure occur, seek medical attention promptly.

Typical AI response, not wrong, but not useful