Lifepo4 Cells (EVE,REPT,Lichen,etc) - Fire ? ..?

[solardad]

Starting a poll and discussion for folks that have had a Lifepo4 cell fire be it from overcharge or an internal short or ???
After seeing what appears to be bad luck with @fhorst , who had two spontaneous and unexplained cells fires (within a year I believe) I think it would be good to know if others are seeing the same issues.

All of the studies that I have seen require an outside source to ignite the gases of a venting cell and even then the actions required to cause such a failure with venting taking place are dramatic and one that I would not expect in a solar system back up setting, very low c rates vs. let’s say an EV use.

Hoping that we can learn from each other.

(Full disclosure I have two 2p16s (64 cells) battery bank of EVE cells for 1+ years)

Thanks

 

[Bud Martin]

I have 12V system.
Litikola 90Ah 9 months.
Lishen 280Ah 7 months
REPT 280Ah 1 month.

 

[Frank in Thailand]

All of the studies that I have seen require an outside source to ignite the gases of a venting cell and even then the actions required to cause such a failure with venting taking place are dramatic and one that I would not expect in a solar system back up setting, very low c rates vs. let’s say an EV use

That's the funny thing.
It was charging a few amps, wile being 15% or so charged.

This was enough to "ignite" the spark.
What else was wrong, I can't be sure.
Can be a mouse who made some damage that almost was enough, and just needed that few amps.
Can be...
My fantasy is as good as yours.
I absolutely do not know for sure.

Fact is, just a few amps charge was enough.

For many years TV standby mode (just a few watts) was responsible for many house fires.
That was before led TV.

Phones (and power banks) are known to selfdischarge without viable reason, with and without charge.

If look only at solar energy storage and fire, you won't find a lot.
Wider view will show a lot more electronic related fires.

Main reasons: damage due ?? (Animals, movement, other)
Component failure often combined with dust, where the dust is the food, and next step for a real probem.
Most components burst or smoke and won't give enough heat to make a fire.

Your fire department probably can give you long list of things that are potentially dangerous.
All that have something to do with electricity, probably also apply to our setups.

Most of us get lucky.
Just the BMS smells wierd and does no longer work.
Of find charcoal mouse...

Some of us have the luck to be "accident magnets" like me

 

[DJSmiley]

If I remember correctly, the first fire @fhorst had was probably due to a misconstruction on the case, accidentaly pushing the cell terminals down 'into' the cells.

I've seen other reports of fires here also. No all of them are 100% sure what caused this, but I do know some others were probably caused by wiring issues or external equipment failure.

If you're pushing 200A, its easy for a bad connection to cause excessive heat.

Since the majority of DIYers doesn't have access to eg laser welding equimpent, that will add some risk (terminals, connection crimps, overtorque and so on).

Building it into a well ventilated wooden box add some risks as well

I do agree with one of the posts @fhorst recently made: If you can get a good deal on a decent factory-build pack like BYD or Pylontech, that might be the safer bet since it does eliminate some of the risks of a DIY build, especially when it comes to casing and connections.


Similar with any new techniques. There also is an increase in housefires due to solar panels and EV chargers. Does this mean you shouldn't use that? No. In the end, 90% of the issues involved can be traced back to wrong installations.

At this moment, at least here in NL, there are barely any regulations for solar installers. Basicly anyone can install panels, without any quality check on their work. The result? Fires.
There has been some official research been done and that eg clearly states the connectors are the main issue. Although MC4 = MC4, the actual details slightly differ from various vendors. Mixing connectors (MC4 from brand A on the panels, brand B used by the installer) does cause less reliable connections. And when pushing 30A @ eg 500V.. that will cause major risks....
Report about this issue (in Dutch) is eg: https://www.rvo.nl/sites/default/fi...t fotovoltaische PV systemen in Nederland.pdf

Some vendors do mention this, but not all contractors are aware of this (or do have proper knowledge). I do see this also in the RV market: I've seen plenty of dealers installing LiFePO4 as upgrade from a regular lead acid, but very limited knowledge on any electrics in general, let alone on LFP.

 

[Steve_S]

Two EV Grade LFP 24V/175AH-8S packs (aoyoupower manufactured cells) Used Cells sold in a prebuilt by ShunBin (AVOID THEM at ALL Costs.)
Two Bulk EVE 280AH 24V/280AH-8S Packs, One Matched EVE-280AH 24V/280AH-8S

No problems at all even pushed to 250A draw & 140A Charge from bank and also the individual 280AH packs. The 175's were discharged up to 175A and charged at 80A also without issues.

All packs are now using 4mm x 20mm (tinned bars)

4 mm	0.1575 ″	5/32 ″
20mm	0.7874"	25/32 ″

 

[Supervstech]

I had cells setup in 16S and while tinkering some cells went to zero, bulged and dumped the electrolyte.
what happens is the bad cell just becomes a shunt, all the other cells in the pack pass their voltage through the bad cell, it ruptures and the pack drops voltage.
I have spares, but I am reluctant to power these cells again. They were used Winston 60Ah cells.

 

[solardad]

I've seen other reports of fires here also. No all of them are 100% sure what caused this, but I do know some others were probably caused by wiring issues or external equipment failure.

Right - one of the reasons I started this thread is to highlight those scenarios since the only one I am aware of is @fhorst 's scenarios (based on using Lifepo4 cells, plenty of issues with Li-NCA)

If you're pushing 200A, its easy for a bad connection to cause excessive heat.

Agree but is that a reasonable scenario outside of a short circuit scenario (dropping a wire or spanner across terminals) and/or vastly under sized battery bank? I guess so if you do not do your homework when designing your system.

Since the majority of DIYers doesn't have access to eg laser welding equimpent, that will add some risk (terminals, connection crimps, overtorque and so on).

Possible but that is where a good torque wrench is key when fastening busbars otherwise I would question the overall system build of anyone given the number of connections that need to be made be it on the DC or AC side. You can't weld everything.. ;-)

I do agree with one of the posts @fhorst recently made: If you can get a good deal on a decent factory-build pack like BYD or Pylontech, that might be the safer bet since it does eliminate some of the risks of a DIY build, especially when it comes to casing and connections.

Agree. It does reduc the chance of human / DIY error but most of these packs are hand built to begin with. So where do you take your chances, with someone working a factory line being pushed to meet a quota or someone obsessing over the correct torque values? I see the similar scenario for those that work around cars like changing their own oil vs. going to the quicky oil change chain. Heard horror stories of oil caps being loose or the wrong filter being used etc..

Similar with any new techniques. There also is an increase in housefires due to solar panels and EV chargers. Does this mean you shouldn't use that? No. In the end, 90% of the issues involved can be traced back to wrong installations.

Are there? That is what I am looking to find out more about since I still have yet to read or hear of these scenarios outside of shoddy install vs. the actual solar item failing - panel/inverter/charger/etc..

At this moment, at least here in NL, there are barely any regulations for solar installers. Basicly anyone can install panels, without any quality check on their work. The result? Fires.
There has been some official research been done and that eg clearly states the connectors are the main issue. Although MC4 = MC4, the actual details slightly differ from various vendors. Mixing connectors (MC4 from brand A on the panels, brand B used by the installer) does cause less reliable connections. And when pushing 30A @ eg 500V.. that will cause major risks....
Report about this issue (in Dutch) is eg: https://www.rvo.nl/sites/default/files/2019/04/Brandincidenten met fotovoltaische PV systemen in Nederland.pdf

Yes. That has been an issue with installs that were done with some Walmart locations (big box store). Crappy connectors.

Some vendors do mention this, but not all contractors are aware of this (or do have proper knowledge). I do see this also in the RV market: I've seen plenty of dealers installing LiFePO4 as upgrade from a regular lead acid, but very limited knowledge on any electrics in general, let alone on LFP.

Agree. I have a friend who I am assisting in reviewing a potential solar install with battery backup and the vendor he is working with has very limited experience is programming the inverter that he has chosen (Sol-Ark). So I have offered to review the install to ensure the settings are not just safe but sustainable.

What I find interesting is that the failure scenario occurred outside of the control of any protection devices - BMS, fuses, breakers etc.. So no matter what brand or product quality his cells had an internal short for some reason.

 

[Steve_S]

Cheap No Name knock off Fuses & Breakers are horrible. Buy only Real Genuine Name brands.
Switches, Breakers etc should all be DC Rated for DC equipment ... none of this AC & DC OK stuff... That's begging for trouble.
Installing Fuses without holders can stress & break them !

I've busted these T-Fuses & they bust quite easily.



What does a "Little loose" look like ? In under 90 seconds ! Thank Goodness for the protector sheet.

 

[chrisski]

BYD or Pylontech, that might be the safer bet since it does eliminate some of the risks of a DIY build, especially when it comes to casing and connections.

I must say I'm a bit suspicious that these are a long term solution and I thank @fhorst for trying these out for us. I do hope they work out.

What I say below is not meant to start a Tesla conversation and derail the OPs thread, but only to explain my thinking.

I'm never one to be the first on my block to try some new large dollar item. I do want a new truck, and the tesla truck claims it will tow 14k LBS, but I don't want to be the first on my block to try it. Although it may advertise 500 mile range, I somewhat doubt you get that same range out of the stronger version especially once it's hooked to my 12 k LBS RV. I expect range to be reduced by 30% to 50%. I could be wrong, but I don't want to spend $70k to find out if I'm right or wrong.

I will however be the first to go to the new restaurant down the road for lunch and tell everyone in the office about whether or not the food is good. I don't lose a years worth of wages if I'm wrong.

 

[Supervstech]

I must say I'm a bit suspicious that these are a long term solution and I thank @fhorst for trying these out for us. I do hope they work out.

What I say below is not meant to start a Tesla conversation and derail the OPs thread, but only to explain my thinking.

I'm never one to be the first on my block to try some new large dollar item. I do want a new truck, and the tesla truck claims it will tow 14k LBS, but I don't want to be the first on my block to try it. Although it may advertise 500 mile range, I somewhat doubt you get that same range out of the stronger version especially once it's hooked to my 12 k LBS RV. I expect range to be reduced by 30% to 50%. I could be wrong, but I don't want to spend $70k to find out if I'm right or wrong.

I will however be the first to go to the new restaurant down the road for lunch and tell everyone in the office about whether or not the food is good. I don't lose a years worth of wages if I'm wrong.

Just like car sales ads… the details are true, but do not accrue…
500 mile range is likely true… and 12K tow rating also true… but don’t expect ANYWHERE CLOSE to 500mile range while towing… I will be infinitely surprised if towing that load you can exceed 100mile range…

 

[chrisski]

I've busted these T-Fuses & they bust quite easily.

So you're saying not to get these? I decided on Blue Sea which is quality, but boy, anytime a cheaper fuse pops up, I wonder if that will be good.

I will be infinitely surprised if towing that load you can exceed 100mile range…

Luckily I work with a couple of innovators who can give me the results. Neither purchased the stronger version of the truck or tow anything to speak of, but at least I will learn what they think of these trucks.

 

[Steve_S]

So you're saying not to get these? I decided on Blue Sea which is quality, but boy, anytime a cheaper fuse pops up, I wonder if that will be good.

That is not the implication, simply fo NOT use this type of fuse without a housing / bracket. I was told "way back when" to attach on to the Batt LUG (on Lead Battery) and wire to E-Panel on the side, the 1st T-Fuse snapped in half, solar co replaced it, that lasted 6 months and disintegrated.

Always use a Class-T Fuse Holder for them. BlueSea uses Eaton Family products, like Bussman, Cooper & Babco as well as LittleFuse (another company, not an Eaton division). That is one thing I can honestly say is that BlueSea does not bugger around with anything they sell, sure it may cost a little more but the peace of mind that goes with their products is worth its weight in Gold.

Recent Fuse Testing that was done with Imports, No Names & Brand Names. The Brand Names (Even imports) all did well, many of the no-names, not so much. 1, 10A ATC fuse took 40A to fail ! There are a few Video's on YT and unfortunately I cannot find the long article that went through a lot of them and it was quite shocking, even no-name breakers failing too early or way too late.

 

[Supervstech]

Yup, fuses are a system, they need to be installed to manufacturers specs… you wouldn’t buy a corvette oil filter and put it in your van and expect to do 0-60 in 5 seconds…

 

[Steve_S]

corvette oil filter and put it in your van and expect to do 0-60 in 5 seconds…

Remember the old nugget, Buy a Vette with Bicycle Tires and call it a Chevette ! goes back a while... << GRINS >>

 

[chrisski]

That is not the implication, simply fo NOT use this type of fuse without a housing / bracket. I was told "way back when" to attach on to the Batt LUG (on Lead Battery) and wire to E-Panel on the side, the 1st T-Fuse snapped in half, solar co replaced it, that lasted 6 months and disintegrated.

Thanks. My class T is getting installed inside with a mount and cover. I won't lie, at a total cost of about $120 for a Blue Sea 225 amp fuse and fuse block, saving $50 crossed my mind.

 

[Steve_S]

Hahaha.... When I leaped into LFP, I changed that mess up and now use one MRBF on every LFP Pack and never worry about anymore. The Lead Bank still has a Class-T Littlefuse in a holder.

I should've mention I guess, when my 1st "T" split apart, the arc (momentary as it was) was Quite Significant.

 

[Sojourner1]

Even with all this hands on experience with real experience good & bad the diy crowd are always looking for the cheap build using cheap components and the fastest/ easiest way (short cuts). We see it in threads every day, initial top balancing just comes to mind first.

I suppose thier are alot of "it won't happen to me" deniers.

 

[Supervstech]

Yup… we are playing around with enough energy to run loads for hours or days… any skipped or incorrectly assembled steps can quickly result in a pile of cinders.
Fhorst’s picture of the before wiring (it’s ok, it lasted 3 days no problem) or whatever could easily have caused the fire. The cells that are manufactured to be sold to assembly plants with strict guidelines, and we mortals slapping them together have no idea what could go wrong, or what should be setup a certain way. I am a LICENSED electrician. I have seen things to curl your toes… and I have VERY little knowledge on battery wiring or cell configuration…
Respect. Procedures. Cable prep. Etc…

 

[Steve_S]

Simply Put, there is a darned good reason why Heavy Welders are DC. It is a Huge Amount of Direct Current that can vapourize metal with a big giant flash ! You getting cooked would be a by-product. Very Easy to do.... yet for some, they flip into thinking that these Batteries are like the AA's you stuff into gadgets... holy crap NO ! but it is an ingrained thing for many...

 

[Gazoo]

There have been other reports of LFE fires and one was using lead acid. The most serious one I recall, other than fhorst's, was reported by @stobbie in this thread and his van was destroyed in the fire The cause was never determined...much specualation as with the other fires. But speculation is good. I am not convinced one way or the other the cell was the cause of the fire is any of these cases.

In the poll I noticed a spot to vote for swelling. There is a big difference between normal expansion and bloating. Some equate swelling with normal expansion. I don't. Terms are terms but I would have used bloating in the poll instead of swelling

Having said that this is a great poll and I do thank @solardad for taking the time to put it together. The more we learn the better.

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