LiFePo4 Cell went up in smoke and flame!!

[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.