Quote:
Originally Posted by SailingHarmonie
Interesting that based on a few still photos, you draw a different conclusion that the professional firefighters on scene at the time.
I have seen a thermal runaway fire in LiFePO4 batteries (a golf cart). It was a truly spectacular event. A major city fire department had a huge response, and all they could do was keep it from spreading. The metal parts of the golf cart--and the ones on either side of it--were literally a puddle of glowing molten metal on the ground. I learned that 100% for sure all those people who say that an LiFePO fire is "impossible" are full of crap. It might be very rare, but it is most certainly NOT impossible.
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You can get everything to burn, even concrete it's just a question of likelihood and other circumstances.
I highly doubt they where lifepo4 in that golf car and if what was the system voltage?
What a lot don't tell you that with rising voltage the
danger of an arcing and not extinguishing light bow that actually bypasses fuse risies significantly and causing the fire. in 12V nearly impossible, in 24V still nearly impossible but in 48V it's possible even in normal surrounding conditions get to get an arcing lightbow with the enormous amount of energy stored in a LiFePO4...the big shadow side of 48V nobody talks about.
All is great with 48V, smaller
cables and smaller
hardware in inverters using less current...all great, nope. From 32V on its can get a
danger to human being and b) fire and desaster risk raising exponentially as eg arcing is possible in standard environments.
That's why 24V is still the safest and best compromise for a vessel and as long as you don't have
electric propulsion no need to go higher.
it's not the cell that gets a runaway which is nearly impossible below 32V...nearly impossible but I had it with a 15kA class T got arced. But that was the only incident like this in 20years dealing with lithium, but lead and especially AGMs redecorated a lot car interiors and burned several cars down quite frequently....not mine as I stayed away from lead where I can but I saw it frequently happened on car stereo competition
events where things are taken to and above limit.
It's not the lifepo4 itself but the high voltage in an EV combined with a) the high constant C draw and b) the enormous amount of energy that's causing all the EV fires of LiFePO4 and derivate cars that causes an non extinguishing
arc that bypasses the
fuses eg between the cells typically found in EV battery packs and start then the desaster.
Completely different as a house bank in a boat, which is used in low C from typically 0.1-0.3C max and is still in majority is 12 or 24V.
An
AGM can get much easier a thermal runaway, a slightly faulty
alternator regulator is all it needs and nobody ever complained about that or an ABYC is caring about that but Lithium we need another strickter and tighter monitoring making all more complex. Nobody talks here about tight monitoring and BMSs for an AGM where it would be really necessary.
I had 3 severe
events with AGM, two in a new car 3 and other 1 month old where AGM just got runaway and I had the luck to have breathing mask from painting and BBQ gloves in the trunk so I could rip it out before it burned the car down, reason a slightly faulty
alternator. Same on my old
ketch where the overload of the bowtruster caused an internal short an also runaway, was tossing the hot AGM batteries
overboard in the habour bay. All where high quality brand AGM batteries. Never ever again AGM on board any vessel I own.