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Spinoff from house burning LFP vs AGM vs Lead Acid - Why not just run the older tried and true stuff?

"Ammo dump" for your battery seems like the safety way to go. Burn, baby Burn!

If inside, I think battery could be enclosed with highly fire resistant material and vented outside (far enough away that flames don't lick the side of the building.)


50ShadesOfDirt said:
In the city, most homes are now packed with enough exotic materials & finishes that even a 5-minute or less fire response from the paid/fulltime fire department might still not be enough to save your house.
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I saw a video comparing natural materials with synthetic.
Natural burned nicely, and continued a bonfire for 30+ minutes.
Synthetic started slow, then within 5 minutes the fumes "flashed over", engulfing room in flames.

Obviously, if you used silk & wool not cotton etc., would be even more fire safe.


Steve_S said:
Lead Acid is NOT SAFE either, I used it for years and managed it with active venting, temp management and constantly futsing with water/acid. The hydrogen given off during Equalizing can be quite high and people do screw up and do so with slightly exposed plates & things happen. Others never have a problem because they are diligent as hell...
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Is the hydrogen ever a problem if there is a hood/vent above to allow rising gas to escape, and fan forced air during elevated temperature (and during equalization, for good measure?)

Seems to me that preventing gas buildup, and preventing unfused shorts, should eliminate fire hazard.

Does FLA ever outgas when not being charged, e.g. due to internal shorts like LiFePO4?
 
Biggest issue with lead acid on a solar system is battery sulfation which leads to reduced capacity and lifespan.

I haven't hit full SOC for this week. LFP doesn't care but lead acid would.

Don't get me going on watering, equalization and depth of discharge. I would have not installed an off grid system with lead acid.
 
On this topic, I think the biggest fire risk is having too high of DC voltages strung up. If you can have your panels close enough and run them at lower voltages (ideally, PWM compatible), safety margins should improve.

That said on LFP vs AGM, I've thought LFP were supposed to be quite safe. Supposedly one of the safest lithium chemistries. In practice, though, I don't know.
 
A chance meltdown can happen with any chemistry and just about any setup no matter how well it's built and to the standards at present. That being said, minimizing risk to life and property through containment and placement of high energy equipment is going to be the way to go. People don't store any other easily combustible energy sources inside or near living spaces without a certain level of protection to warrant and coincide with the type of energy source being stored.

That being said, with the amount of energy I plan on storing in one place, it will be protected by CMU block walls all the way around with an open side to a detached shed structure. I was going to use the shed as is, but have decided to add a small blockbuilt extension, rebared, and entirely concrete filled, with SBC plaster siding; insulated siding...

I don't even park my vehicles in the garage as it's a finished area, but not to any standards that would save any of the structure should the energy in the gasoline be released. It's parked outside in a driveway and at closest, periodically in a carport at the farthest end of the home from the bedrooms.

Color me worried, but I think the total energy stored within a given area, and potential release velocity, should be taken into account as to how much protection in the area is needed.
 
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We've seen reports of where someone's lead acid battery exploded. Granted, it didn't burn the place down, but the potential is there for some damage.

That's why no matter what, you need to just be safe. Treat these things with the utmost respect.
 
Saw that recently. He had an automatic waterer, and the floats stuck so battery went dry. Must have arced inside, and blew up.
(I think I remember he said he was messing with the system when it went off, but no mention of injury. Maybe it was completely dry?)

I cooked an AGM motorcycle battery by leaving an unregulated charger attached. It stank up the place, and swelled so it required violence to remove from the pocket in the frame.

I've known people who said they blew up a car battery by wiggling clamps on terminals. Always remove power before adjusting.
 
hwy17 said:
1. Stuck in their ways. Lead acid is familiar, LFP is unfamiliar. They know how to design lead acid, they don't know how to design LFP. Lead acid can be voltage controlled, LFP normally requires potentially troublesome comms unless you're an expert in running an open loop system.

2. There is something to be said for the quality of proven lead acid system design over the years. You will talk to some off gridders who don't think about their batteries, don't sit around watching them, they just water them and buy replacements every 5-10 years and otherwise live their lives. I can respect people not wanting to fix what ain't broke.

3. Lead acid are north american made and have a very good existing recycling chain. If one had isolationist ideals, those are positives. I have big doubts that LFP recycling will ever take off at scale. But then again, try designing a solar system of any kind without Chinese parts. It's unlikely.
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The biggest thing for me is the Chinese manufacturing standards (inconsistent at best) on top of the complete separation for liability (anything overseas). I don't know about everyone else but when I see "Made in China" my expectations are low. I am not surprised to see a failure, and the downside is there is nobody standing behind it.

Is LFP technology superior? Absolutely yes.

Do I want a LFP battery made in China, purchased from Alibaba, no thank you.

I am very happy with my Trojan L-16 bank. Going on 7 years old and Id buy the exact same thing again if it failed today.
 
I buy all of my cells in the states.
Delivered 3 days after ordering.
I'm not waiting months to see if I get what I paid for.
 
timselectric said:
I buy all of my cells in the states.
Delivered 3 days after ordering.
I'm not waiting months to see if I get what I paid for.
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That would certainly be preferred.

I look forward to more assembled LFP battery options from US companies. We have a ways to go before the assembled price is competitive with a diy cell build though.
 
Don't think it was just an arcing fuse.

1) Something caused over-current
2) Something was able to be ignited by the arc
 
SparkyJJO said:
Takeaway is to use fuses with higher AIC. 5 years ago that wasn't as well known for 48V LFP.
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I installed my first LiFePO4 system in 2012. High AIC fusing was well known as a requirement then, as well as fusing between parallel packs, and using pre-charge for arc protection of contactors.

It seems in many ways the increased use of YouTube for “learning” has decreased the availability of quality information.
 
hwy17 said:
Also, cost. Lead acid is more expensive now.
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Particularly if you take life cycle cost into account. Lead acids age out a lot faster than LFP.

LFP is quite safe.

Had they been the first lithium batteries instead of NMC, we wouldn't have so much fear of them and NMC would look horribly dangerous by comparison.

Mike C.
 
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