LiFePo4 Cell went up in smoke and flame!!

[Tulex]

Better get another cup. Still not edited correctly.

Ummmm.............

I wasn't going to say anything, I'm already in the doghouse.

 

[Zwy]

I wasn't going to say anything, I'm already in the doghouse.

It's all in fun and jest, it was confusing.

Sorry Steve but the way it was written I about sprayed coffee all over my screen.

 

[SeaGal]

Tape counts as compression, right?

Not unless it provides an even pressure across the cell end plates.

I found the thread that I recalled in my posing #20 on page 1 of this thread...

280AH EVE CELL LASTED ONLY TWO YEARS

Hello All, I was one of the early purchasers of the 280ah EVE cells from Amy and one of the cells has malfunctioned already. Do these things have a warranty? How can I reach Amy now days? Is she the one in Houston now? About the bad cell, it has swollen tremendously and will not take a...

diysolarforum.com

 

[Ampster]

Tape counts as compression, right?

Not as effective as thread rod and compression plates as noted by @SeaGal . Tape only holds corners and can't apply much pressure to center of first and last cell. Expansion of all cells could cause tape to deform outer edges of outside cells.

 

[rodrick]

Hey the pictures were correct and that’s what most guys want in there reading material good pictures?

 

[Zapper77]

Not unless it provides an even pressure across the cell end plates.

Sorry Sarcasm didn't come across efficiently in my text. I'll add a laughing emoj next time. ?

 

[GSXR1000]

the vent didn't let go.. that looks like a heat issue with current and bad connection appears the terminal melted away.. what was on?

 

[Ampster]

the vent didn't let go.. that looks like a heat issue with current and bad connection appears the terminal melted away.. what was on?

That would be my guess as well. Also with LiFePO4 the smoke was presumably the melting insulation on the cable.

 

[JJJJ]

What are temperatures in your area? Just curious what interior temperatures might be getting to in the vehicle. Just a thought…

 

[mpopo]

Over charged? Dented Cell corner?

Overcharged definitely not. Dented corners. All looked ok, maybe? Not sure. But would say not ..

 

[Alkaline]

Potential Problems:

1) Loose bus bars heat up?
2) Rubbing Cells Poorly Secured could have caused a short circuit.
3) Grade B cells and weak/damaged case weldings. This seems to happen more and more, starting form the bigbattery fiasco and now seeing people having issues with 18650 grade B cells, I think more and more we are finding these things creeping up. I just looked at your picture and QR code location would indicate grade B.

Overall, I would have a chat with the "professional" who did your install...

 

[mpopo]

A further away pic along with close up is more useful for others that aren't in your van with you.

More pics help of the whole setup makes it easier to see possible issues. How are they secured from movement?

with nylon straps bolted to the floor of the van. quite impossible to move.

Were you recently driving the van? You said it wasn't running but were you driving it earlier in the day?

Actually no. Although this set of cells was recently plugged into the system. So it had about a week of charging/discharging with not a lot of driving. (currently at home, not traveling)

Hmmm.

That image doesn't show much. It is widely known the bare cells need drastic support and separation from each other.
In a mobile situation, ESPECIALLY SO!

Ok, with this I would totally agree. They were not. That might be one of the reasons. maybe? Still hope it is a defective cell and a seller which is gone from the face of the earth.

What is the black tape around the edge of the battery and under it? We have seen images on this forum before where some tight strapping tape has deformed the prismatic case. In that case the user had over tightened strapping just on one part of the cell, rather than applying even pressure for support. Also agree with comment above about insulation between and under the cells - the blue wrapping is not strong enough on its own.

Black tape was there to secure the cells before the silicone glue started to work. One part of the black tape was also to insulate the connections And yes, better separation. Although, the problem happened inside one cell. the others look intact, but still not planning on using them further, as per the dubious seller.

I feel if the battery legitimately caught fire, it would not have been extinguished. Like @labeeman said.

Without more pics or info, I couldn't draw a conclusion on what caused it though.

Also, I don't think I've heard of a 320ah Cell. Maybe that should have been a give-away for a cell that a company is trying to just dump on someone because they know they are Grade C or worse. The company no longer being around leans towards this theory heavily.

As I said, I was there, it all happened in seconds. After seeing the flame and extinguishing was 5 seconds. And it began slow. I learned that LiFePo4 fire is not the same as standard Li-ion (cobalt)

 

[Supervstech]

with nylon straps bolted to the floor of the van. quite impossible to move.

Actually no. Although this set of cells was recently plugged into the system. So it had about a week of charging/discharging with not a lot of driving. (currently at home, not traveling)

Ok, with this I would totally agree. They were not. That might be one of the reasons. maybe? Still hope it is a defective cell and a seller which is gone from the face of the earth.

Black tape was there to secure the cells before the silicone glue started to work. One part of the black tape was also to insulate the connections And yes, better separation. Although, the problem happened inside one cell. the others look intact, but still not planning on using them further, as per the dubious seller.

As I said, I was there, it all happened in seconds. After seeing the flame and extinguishing was 5 seconds. And it began slow. I learned that LiFePo4 fire is not the same as standard Li-ion (cobalt)

Which end failed? Was it by chance the negative end?

 

[Skypower]

“Black tape was there to secure the cells before the silicone glue started to work.”

Be very careful what type of silicone you use around electrical. The acidic type has a strong vinegar smell and is highly corrosive to copper, zinc, tin, lead and most aluminum alloys in the vicinity along with the presence of moisture(even humid air). It does not need to be in contact with the metal to be damaging and it can outgas for many months and much worse in an area of poor ventilation. Use electrical grade silicone or ShoeGoop around your electrical. Note, ShoeGoop can soften or melt some plastics. Have you ever sealed up a box really good with common silicone to keep the rain out just to open it up later and all the wires are a green mess? Now you know.

 

[HRTKD]

Tape counts as compression, right?

I don't consider it to be acceptable, certainly not in a mobile environment.

With respect to Steve's pictures, we don't know which direction the pouches (if the cells use pouches) are oriented within the cell. As I recall, the EVE cells are like a jelly roll, so they have no uniform orientation within the cell.

It's been a while since I thought about it, but I thought there was a thread a couple years back where a forum member got in contact with an EVE engineer and they said long side down was OK. There was so much confusion on the topic that I threw up my hands and designed my system so the cells were oriented terminals up, even though long side down would have given me much more flexibility.

I checked my copy of the 2019 EVE data sheet and it doesn't address orientation.

 

[mrrjm]

Everything I do with lithium now is UL approved only. No more home made batteries or chinese inverters. Not worth the risk!

 

[HRTKD]

Everything I do with lithium now is UL approved only. No more home made batteries or chinese inverters. Not worth the risk!

I'll make a DIY battery for myself, but if I was in business, I think I would have to go off-the-shelf to reduce the liability.

 

[OffGridForGood]

From the photo it looks like a short to the cell case.
Aliexpress is not a place to buy cells, this is where they dump crappy cells, take you money and change the name of the vendor every 3-6 months.
I suggest you pull the rest of those cells and replace with new ones from a vendor with an EU warehouse selling authentic cells with test reports.
If the cells don't fit the space with proper separation materials, make a better space, or go with a smaller cell that does fit the space.
Glad you and the Van are both ok!

 

[42OhmsPA]

with nylon straps bolted to the floor of the van. quite impossible to move.

Actually no. Although this set of cells was recently plugged into the system. So it had about a week of charging/discharging with not a lot of driving. (currently at home, not traveling)

Ok, with this I would totally agree. They were not. That might be one of the reasons. maybe? Still hope it is a defective cell and a seller which is gone from the face of the earth.

Black tape was there to secure the cells before the silicone glue started to work. One part of the black tape was also to insulate the connections And yes, better separation. Although, the problem happened inside one cell. the others look intact, but still not planning on using them further, as per the dubious seller.

As I said, I was there, it all happened in seconds. After seeing the flame and extinguishing was 5 seconds. And it began slow. I learned that LiFePo4 fire is not the same as standard Li-ion (cobalt)

I'm glad you and the van are OK. I have to say wow! If a professional built that I'm seriously in the wrong business.

 

[SilverbackMP]

Everything I do with lithium now is UL approved only. No more home made batteries or chinese inverters. Not worth the risk!

I think my REC BMS based home brew and true Grade A cells (likely EV grade) has better components than most UL certified units. YMMV.

That being said, if something was available off the shelf that communicated with SMA and that wasn’t stupidly priced, I would have gone in that direction.

 

[sunshine_eggo]

Summary:

Questionable cells from a questionable seller means questionable quality.

A very atypical compact installation that does not follow best practices with regards to isolation, orientation, separation and compression.

Too many factors force a conclusion of a likely unfavorable outcome.

 

[JJJJ]

It would be interesting to go through an average home to see how many things never went through formal UL testing.

Many DIY batteries on this forum have been painstakingly built with redundancy and safety features added in. A number are mobile. Would venture to guess that more are stationary which dramatically reduces the risk of moving wires or cells.

Have also read accounts of prebuilt batteries which encountered safety concerns. Even a UL approved extension cord poses a risk if improperly used.

My guess is that as the industry shakes out UL will be much more common. In the meantime careful planning and getting critiques from other knowledgeable users on this forum goes a long way.

 

[Skypower]

It would be interesting to go through an average home to see how many things never went through formal UL testing.

Id hazard to guess that probably half of the stuff you find in Walmart or Amazon is suspect even if it says UL. UL probably quashes them and they pop up somewhere else under different name and color.

 

[Marinepower]

That's a very tight space for those cells. Nothwithstanding the nylon straps, it looks like those cells could vibrate laterally. If there was a largish (1 awg) cable & lug connected to the pictured end-terminal without some very carefully implemented strain-relief on the cable, it seem easy for it to develop resistance as the lug worked lose over time.

This is all pure conjecture on my part - but I have had to hunt down and re-work poor connections several times in a marine application that has much less vibration than a van/rv. I have recently moved to Fortune / Frey cells for their beefy 3/8th copper terminals to try to avoid this issue.