Was there a cover over the cells? Was trying to understand if the red plastic holder you made on the far end melted because of the heat of being in the battery enclosure with a lid on or the cells on that end were that warm to melt it. It also looks like there was a ply wood floor the cells were on and it did not burn the flooring?
Lishen 272AH thread?
- Thread starter nebulight
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stobbie
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There was no cover over the cells. The battery was disconnected from the rest of the campervan. There was no power whatsoever on any other wiring.
Only the charger, bms and battery where connected together. BMS is not heavily burned, it was behind the half of the cells that have survived. The wiring has melted of the bms, the solder has melted. The bushbars made perfect contact with the poles, I know because I have improved that after installation, I'm 100% sure there was no heat build up at the poles. My charger was connected at 30Amps with a crocodile clip. And it is my home charger, and I know the clip always heats up a little bit, at first I always kept an eye on it because of that. But it never got warmer then hand warm, so lately I haven't been paying attention to that anymore. I never leave this charger on overnight, this was the first time that I did this.
The cells were at 7% when I connected the charger, so overcharging is almost impossible after charging for around 12 hours with 30 amps on a 545A bank.
Charger is not too burned as well. So my guess is heat build up at the alligator clip.
Or... what would happen if the chinese charger developped a voltage problem? And it would have started charging at 20 or 30 volts instead of 13,6? I don't know if something like that can happen with such a converted server power supply..
Only the charger, bms and battery where connected together. BMS is not heavily burned, it was behind the half of the cells that have survived. The wiring has melted of the bms, the solder has melted. The bushbars made perfect contact with the poles, I know because I have improved that after installation, I'm 100% sure there was no heat build up at the poles. My charger was connected at 30Amps with a crocodile clip. And it is my home charger, and I know the clip always heats up a little bit, at first I always kept an eye on it because of that. But it never got warmer then hand warm, so lately I haven't been paying attention to that anymore. I never leave this charger on overnight, this was the first time that I did this.
The cells were at 7% when I connected the charger, so overcharging is almost impossible after charging for around 12 hours with 30 amps on a 545A bank.
Charger is not too burned as well. So my guess is heat build up at the alligator clip.
Or... what would happen if the chinese charger developped a voltage problem? And it would have started charging at 20 or 30 volts instead of 13,6? I don't know if something like that can happen with such a converted server power supply..
Could the alligator clips have come off? Do you have link to the charger you used?
I didn't read all the responses. However from the fairly low res photos, the fire appears to have started in this area. I see a fair bit of loose wiring, and possibly some 120V stuff. Lots of possible hot spots, with plastic and wood. Given the history with LFP packs, and the lack of flammable materials within a couple inches of the battery terminals, I suspect the ignition source was in this area.
Its not typically called for, but one of these fire extnguishing tubes can be installed in a compartment easily.
Its not typically called for, but one of these fire extnguishing tubes can be installed in a compartment easily.
240V even, since they are European sockets.
Since he also has some Dutch video's on his channel I'm quite sure he's from the Netherlands
Doesnt change the fact that it completely sucks to get your RV damaged by fire or smoke...
Agree on the lowres photo's, some hires photo's might help guessing the cause. (Will has recently upgraded the max file size to allow for better images)
@stobbie : Succes.. mooi kut om je werk zo aan te treffen, ook al is t maar materiaal.
Since he also has some Dutch video's on his channel I'm quite sure he's from the Netherlands
Doesnt change the fact that it completely sucks to get your RV damaged by fire or smoke...
Agree on the lowres photo's, some hires photo's might help guessing the cause. (Will has recently upgraded the max file size to allow for better images)
@stobbie : Succes.. mooi kut om je werk zo aan te treffen, ook al is t maar materiaal.
I don't see any signs that the cells themselves were the ignition point (that doesn't mean much). There really isn't much flammable material near the cell terminals, and even if one did hard short internally, they almost never catch fire.
From the previous overall photo I would bet the ignition point was in the wiring or junction boxes in the back corner. Notice how there wasn't any burning below a certain belt line, that would indicate the air flow and low heat in that area. Ignition points often have the lowest temperature, as the fire progresses it gets hotter. However just above and to the right the damage to the wood gets worse, which would seem to support this. By looking at the "alligator" pattern of burning in the wood, its possible to asses the relative temperature of the flames. As the fire burned to the right, it got hotter, and eventually the cells started failing, and the electrolyte vented and ignited as it boiled.
From the previous overall photo I would bet the ignition point was in the wiring or junction boxes in the back corner. Notice how there wasn't any burning below a certain belt line, that would indicate the air flow and low heat in that area. Ignition points often have the lowest temperature, as the fire progresses it gets hotter. However just above and to the right the damage to the wood gets worse, which would seem to support this. By looking at the "alligator" pattern of burning in the wood, its possible to asses the relative temperature of the flames. As the fire burned to the right, it got hotter, and eventually the cells started failing, and the electrolyte vented and ignited as it boiled.
stobbie
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The rest of the wiring was disconnected at the time of the fire. There was no power on any of the wiring.
Only power was on battery, charger and BMS. Charger was on extension cord, because there was no power in the camper. Extension cord remained undamaged.
Main positive feed from battery to camper was disconnected, main fuse was removed.
I have cleaned a lot yesterday, and removed a lot of the interior. Today I have decided that I will not repair it anymore. There is too much smoke damage on everything unfortunately.. I'm going to look at anothec campervan tomorrow, but it's very hard to part from my own van because I really liked it..
Only power was on battery, charger and BMS. Charger was on extension cord, because there was no power in the camper. Extension cord remained undamaged.
Main positive feed from battery to camper was disconnected, main fuse was removed.
I have cleaned a lot yesterday, and removed a lot of the interior. Today I have decided that I will not repair it anymore. There is too much smoke damage on everything unfortunately.. I'm going to look at anothec campervan tomorrow, but it's very hard to part from my own van because I really liked it..
schmism
Solar Addict
as some who has a firefighter2 certfication (having served on a fire dept)
is the source of the fire. NOT the cells.
We need more information about the components in the corner.
Your story also suggests that there was no active (flames, items giving off smoke) fire when you found the mess.
What 3d printing plastic did you use? Most will sustain a flame. Most electrical components will not. So while the insulation on a wire will melt off even if the wire gets red hot, they typically will not "burst" into flame. They require an active flame to "burn".
IF you did not "put out the fire" this means it self extinguished. Typically this happens when whatever is capable of self ignighting (producting a flame) runs out of fuel. (as an example, all the plastic burns up) once that flame goes out the rest of the stuff stops burning (as its designed to do)
What small amount of material was in that corner that would have sustained a flame, but then burnt out.
is the source of the fire. NOT the cells.
We need more information about the components in the corner.
Your story also suggests that there was no active (flames, items giving off smoke) fire when you found the mess.
What 3d printing plastic did you use? Most will sustain a flame. Most electrical components will not. So while the insulation on a wire will melt off even if the wire gets red hot, they typically will not "burst" into flame. They require an active flame to "burn".
IF you did not "put out the fire" this means it self extinguished. Typically this happens when whatever is capable of self ignighting (producting a flame) runs out of fuel. (as an example, all the plastic burns up) once that flame goes out the rest of the stuff stops burning (as its designed to do)
What small amount of material was in that corner that would have sustained a flame, but then burnt out.
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My take on this (before reading the other posts to avoid being biaised):
I think the fire was started either by the big Victron device in the middle (can't read the label so not sure what it is) or by something behind it (where there is all the wires, etc...).
The fact the cells in the front are not bloated pretty much rules out an over charge or a big short being the cause of the fire (and LFP cells don't really catch fire even on a dead short, but they can make something else catch fire though).
It's hard to tell more just from the single angle and relatively low res picture tho. Removing the charred wood pieces which fell on top of the equipments would help a lot seeing from where the fire might have started.
NB: I'm not a firefighter, expert, or anything in the fire domain. It's just educated guesses, nothing more.
I think the fire was started either by the big Victron device in the middle (can't read the label so not sure what it is) or by something behind it (where there is all the wires, etc...).
The fact the cells in the front are not bloated pretty much rules out an over charge or a big short being the cause of the fire (and LFP cells don't really catch fire even on a dead short, but they can make something else catch fire though).
It's hard to tell more just from the single angle and relatively low res picture tho. Removing the charred wood pieces which fell on top of the equipments would help a lot seeing from where the fire might have started.
NB: I'm not a firefighter, expert, or anything in the fire domain. It's just educated guesses, nothing more.
The voltage would be clamped by the battery; i.e. the voltage can't rise to dangerous levels if the battery isn't overcharged, which very probably didn't happened since, as you said, the current and time were too low for the battery to be overcharged, and since the cells didn't expand (excepted the ones near the fire of course).
Where was this charger placed in the picture (if it even is in the picture)?
Yep, to me the cells were damaged by the fire, and aren't the cause of the fire.
Metalophile
Analytical Chemist
Exactly where was the charger attached? Did you attach it to the PV inputs of the Victron? Did you clip it to the main terminals of the battery, bypassing the BMS? Could you tell if any of the fuses had blown? What was the make and model of the charger? Was the charger sitting in that corner of the box that was charred or was it sitting outside of the box? Does your BMS have bluetooth? If so, maybe there is data about what happened on the device it was bluetooth connected to?
I had a smaller incident in my garage a few weeks ago where I was charging a 30AH 4S used LiFePO4 pack using a cheap Chinese DC-DC step down converter "rated" for 5A. I was feeding it with 24V from my big pack stepping down to about 13.5 volts. Last time I checked it was pulling about 3.5A, and I thought it was fine. An hour or so later, I smell an electrical burning smell from the garage and the DC-DC converter had smoked and charred badly. Good thing I had left it sitting on a non-flammable metal surface.
I had a smaller incident in my garage a few weeks ago where I was charging a 30AH 4S used LiFePO4 pack using a cheap Chinese DC-DC step down converter "rated" for 5A. I was feeding it with 24V from my big pack stepping down to about 13.5 volts. Last time I checked it was pulling about 3.5A, and I thought it was fine. An hour or so later, I smell an electrical burning smell from the garage and the DC-DC converter had smoked and charred badly. Good thing I had left it sitting on a non-flammable metal surface.
Just watched this video where someone performed a test to see if a prismatic cell would catch on fire.
He discharged the cell completely and punctured the case - the result ? SMOKE & FIRE!
Granted - this is extreme abuse - but it seems to suggest fire is a possibility...
He discharged the cell completely and punctured the case - the result ? SMOKE & FIRE!
Granted - this is extreme abuse - but it seems to suggest fire is a possibility...
A fully discharged cell wont vent or get hot enough to catch fire, so I wonder if they actually fully discharged it or not? Typically that's 2.5V or so.
Typically just puncturing the cell (even fully charged) isn't enough to set the electrolyte on fire, and I have seen a number of tests to that effect. Though its always been possible under the right conditions.
Cobalt flavored cells will almost always catch fire with a puncture, at least from the testing I have seen.
Typically just puncturing the cell (even fully charged) isn't enough to set the electrolyte on fire, and I have seen a number of tests to that effect. Though its always been possible under the right conditions.
Cobalt flavored cells will almost always catch fire with a puncture, at least from the testing I have seen.
@HighTechLab posted the following in his YouTube comments:
I think the gasses only ignited because when I sent the spike through it the second time, it cased some level of internal shorting that made a spark that ignited the electrolyte that was being vaporized.
I don't know if he has read this thread but maybe he will stop by and comment here.
REPLY
I think the gasses only ignited because when I sent the spike through it the second time, it cased some level of internal shorting that made a spark that ignited the electrolyte that was being vaporized.
I don't know if he has read this thread but maybe he will stop by and comment here.
REPLY
Bud Martin
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I think when he shorted out the battery pack terminals to discharge the battery pack, the BMS may have shutdown so no output shown at the pack terminals but the battery is still has lots of Voltage on each cell.
