Nasty LiPo fire

[Hillhater]

guys, ..a few questions to those experienced in this area..

1) does anyone know (or like to make an educated guess) at exactly what final QC checks the manufacturers do on these cells to ensure "Suitability for use" ?? ..
2) Can we as users replicate those checks (or better ones) some how ??
3) What recommendations does anyone (Knoxie ?) have for reliable, compact, inline fuse units that should be incorporated into harnesses for each pack to give some basic protection against current overload. ??
4) is thermal monitoring of packs practical ( or worthwhile) and what devices are readily available for this ?
5) what other pack monitoring could be considered ..pressure, gas detection, smoke detectors , etc ?
6) As a last resort, what is the best way of dealing with a lipo fire ? ( powder, foam, sand, blanket, water ?)

 

[EBJ]

Well, you can use a charging/discharging charger such as the hyperion or iCharger line to do a test.
I used 6x 12v 50w halogen lights ( 3s2p ) to discharge my 5ah 10S packs at a rate of 8-9amps which took about 30 minutes per pack, and charted the voltage of each cell using the monitor mode of my iCharger 1010b+, using the included logview software.

How would you recommend a test without using logview?

Cells are usually around 3.8 when shipped so how about if we charge up to 4.1 and check balance taps, then discharge with the charger (e.g. hyperion) down to 3.5 and check balance taps, then charge back up to 4.1 and check balance taps and if it seems good, maybe it's all good? Would a weak cell pop up in a non-balance charge (we'd see 1 or more cells off from the others by a lot (more than .3v)) after a charge?

According to the back of the Hyperion 1420i box:
"You can download the Hyperion EOS Control & Data Suite at http://www.hyperion-world.com/ecds free of charge."

EDIT: above link didn't seem to work... here is what I think it is:
http://media.hyperion.hk/dn/pc/ecds-man/Beforeyoustart.htm

so it seems you CAN log your discharging w/ a Hyperion. right?

 

[drunkencat129]

see thiss is y im makeing a minaral oil filled battery case for when i get my lipo pack in did a video a long time back with stevo where i put some cells in a jar of minaral oil and thay vented and then nothing just went dead because after case riped open the oil filled and cooled the plates also did extream test over charged them with 24v 100a lol and all thay did was sit there till it started boiling the oil but it took like 5 min for it to happen by then u whould notice the problem and also save the other packs next to the cells that failed hear is the link to the vids we did lol me and stevo where board lol when we did it lmao
[youtube]http://youtu.be/1PdLzYufSqw[/youtube]

 

[drunkencat129]

also for got it works amazing if u are chargeing over night

 

[EBJ]

see thiss is y im makeing a minaral oil filled battery case for when i get my lipo pack in did a video a long time back with stevo where i put some cells in a jar of minaral oil and thay vented and then nothing just went dead because after case riped open the oil filled and cooled the plates also did extream test over charged them with 24v 100a lol and all thay did was sit there till it started boiling the oil but it took like 5 min for it to happen by then u whould notice the problem and also save the other packs next to the cells that failed hear is the link to the vids we did lol me and stevo where board lol when we did it lmao
[youtube]http://youtu.be/1PdLzYufSqw[/youtube]

throw a few periods in there next time :wink:

 

[neptronix]

Well, you can use a charging/discharging charger such as the hyperion or iCharger line to do a test.
I used 6x 12v 50w halogen lights ( 3s2p ) to discharge my 5ah 10S packs at a rate of 8-9amps which took about 30 minutes per pack, and charted the voltage of each cell using the monitor mode of my iCharger 1010b+, using the included logview software.

How would you recommend a test without using logview?

Cells are usually around 3.8 when shipped so how about if we charge up to 4.1 and check balance taps, then discharge with the charger (e.g. hyperion) down to 3.5 and check balance taps, then charge back up to 4.1 and check balance taps and if it seems good, maybe it's all good? Would a weak cell pop up in a non-balance charge (we'd see 1 or more cells off from the others by a lot (more than .3v)) after a charge?

If you don't have a hyperion or iCharger that is capable of cell-level logging, the celllog 8m / 8s units that have the USB ports can connect to the logview software and do the same trick for one pack.

You can use two 12v halogen lights as dischargers for 5s-6s packs. Faster than the 0.5 amp rate of many balancing chargers.

 

[knoxie]

Ammo boxes and mineral oil :? , I think the plot is being lost somewhere here, if you feel the cells are so dangerous you need to keep them in an ammo box then you really ought to think twice about using them ha ha, this is all getting rather silly IMHO, go back and watch Lukes videos and see just how hard it is to get one of these cells to go off, you may as well all go back to using lead acid batteries if you are all that worried as they are most likely the safest bet.

The facts are we just dont know the problem that existed in John or Keplers packs they could have been simply manufacturing defects, I think its pretty clear though that these defects will most likely surface in the first few cycles so if folks are concerned I would just buy a couple of the lipo bags, run them on the bike for a few cycles and then go see how they balance and charge.

I have been messing about with Lipo for such a long time, they can take a lot of abuse but they will as we have seen procrastinate if you take them over the edge, also some cells take a few charge discharge cycles to budge, those graphs if on new cells don't necessarily show bad cells, I have seen this myself, 4 or 5 cycles and they match the rest of the pack.

 

[dogman dan]

QC is the issue I'm sure. I had every single one of three 4s turnigy 30c packs puff. One came that way, glad it didn't flame the Post Office! The other two began to puff after less than 15 cycles. Never got hot in use, just puffy. They sit in a steel box now, till I get around to trying to make em go. Something was not right about that whole batch of cells that got made into 4s packs.

But as we clearly see here, although they can be very hard to get to flame, you just don't want to leave em laying around on the carpet. Can't think of much better way to test run em, that buying an RC toy to do the break in discharges. 8) Or a smaller ev, like a scooter that can pull some good amps one pack at a time. For me, I have my lawnmower in the summer.

 

[auraslip]

Well that's scary. 15 cycles until the dud showed up? Yikes. It'd take a lot of testing to sort through a whole pack.

BTW, what's hobby kings return policy with these dud cells?

 

[Ypedal]

Ypedal process :

- Open box, inspect for physical damage
- Plug in celllog / HK ballancer and check cell voltages
--- If all cells are in the 3.7 to 3.9v range, all is good so far.. if any are way off, make note of them on the pack..
- Plug into charger and fully ballance charge to 4.20v per cell
- Run a discharge cycle while monitoring cell voltages with cellog gizmo or HK gizmo, i like to use this :
http://www.ypedal.com/Lbd.htm

--- If all cells deliver rated capacity above 3.0v on the first cycle, you got a good healthy pack

- Charge again to full 4.20v, let pack sit overnight, good healthy cells will retain 4.18v + overnight.. bad cells will drop to 4.15 or less..

Then you cycle the cells with more amps and manually touch the packs feeling for hot spots.. if all checks out.. Rock on !

 

[auraslip]

Who else thinks Ypedal should repost that in a new thread and then sticky it in the FAQ?

 

[mud2005]

Who else thinks Ypedal should repost that in a new thread and then sticky it in the FAQ?

exactly what I was thinking. I hate to see good concise info lost in a long thread.

 

[EBJ]

Ypedal process :

- Open box, inspect for physical damage
- Plug in celllog / HK ballancer and check cell voltages
--- If all cells are in the 3.7 to 3.9v range, all is good so far.. if any are way off, make note of them on the pack..
- Plug into charger and fully ballance charge to 4.20v per cell
- Run a discharge cycle while monitoring cell voltages with cellog gizmo or HK gizmo, i like to use this :
http://www.ypedal.com/Lbd.htm

--- If all cells deliver rated capacity above 3.0v on the first cycle, you got a good healthy pack

- Charge again to full 4.20v, let pack sit overnight, good healthy cells will retain 4.18v + overnight.. bad cells will drop to 4.15 or less..

Then you cycle the cells with more amps and manually touch the packs feeling for hot spots.. if all checks out.. Rock on !

X3! Start up a new thread and sticky this stuff. Perhaps include step-by-step instructions so I ask less questions. haha.
first question: What do you drain the cells to on their first cycle?

 

[Ypedal]

Monitoring all cells during discharge it's usually obvious witch one is the lowest voltage to keep the eye on, once that cell hits 3.3~3.1 it's time to unplug because it goes fast from there on, whatever capacity you get on the Cycle Analyst/Watt's up/ Etc meter is the " pack " capacity...

If that one cell drops off way early, like at 3ah or something, you got a bad cell in that pack....

If that one cell drops off at something like 4.8ah on a 5ah pack... it's reasonable....

Just do not allow any cell to go below 3.0v as an absolute minimum....

 

[number1cruncher]

Who else thinks Ypedal should repost that in a new thread and then sticky it in the FAQ?

I thought the same thing! Very concise and understandable!

 

[wojtek]

http://www.endless-sphere.com/forums/viewtopic.php?f=5&t=29361

 

[JohnC]

.

 

[liveforphysics]

Monitoring all cells during discharge it's usually obvious witch one is the lowest voltage to keep the eye on, once that cell hits 3.3~3.1 it's time to unplug because it goes fast from there on, whatever capacity you get on the Cycle Analyst/Watt's up/ Etc meter is the " pack " capacity...

If that one cell drops off way early, like at 3ah or something, you got a bad cell in that pack....

If that one cell drops off at something like 4.8ah on a 5ah pack... it's reasonable....

Just do not allow any cell to go below 3.0v as an absolute minimum....

I don't let LiPo even go below 3.4-3.5v anymore.

 

[neptronix]

Me either, but during a discharge test, you get more information about the cells if you stop when the first cell drops to 3.0v.

My LVC is set to 3.45v/cell now. I have 0.7v of voltage drop at peak amps, so that works out to about 3.5v/cell, which is very safe, even for packs with a serious outlier.

 

[knoxie]

8) glad my input is appreciated by some folks at least and yes like Luke I cut off at 3.5V per cell, this thread has been really interesting to me in so many ways, I agree we all need to know the risks thats for sure, just mitigate them and enjoy the best value for money energy you can get next to gasoline! gas prices are going up, Lipo prices are coming down, the price of solar panels are coming down, I see something very cool happening here 8) dont be scared of technology, embrace it and lets all move forward at great speed using clean energy...what a better place this world will be without the shackles of oil and the war, death and disasters that go along with it.. I am an optimist of course! what a great hobby this is..and what a great bunch you all are too

 

[jonathanm]

I've been watching this thread with interest, because I'm new to this and wanted to hear what the more experienced people had to say about it.....but I've recognised something in myself already that I think is the number one safety issue with Lipo, and I think played a major factor in this incident - complacency.

I realised before my motor arrived that SLA wasn't gonna cut it, and ordered some LiPo on the advice of people here....While I was waiting for it to arrive, I scoured the web for safety info....watched all kinds of videos and read all kinds of reports....with the result being I basically scared myself sh!tless

When my batteries arrived, I nervously hooked them up to the charger in a cinder block bunker with the back door open and in throwing distance, and a fire extinguisher and a metal stew pot next to me. haha...I carefully measured everything first, and quadruple checked the wiring - squeezed them, wiggled them, eyeballed them, I even measured their thickness with digital calipers so I could detect the tiniest amount of puffing..... haha seriously, my heart was pounding...

I cycled them a few times, watching them like a hawk, checking voltages and balance, and still half expecting them to go up like a

Literally within a couple of weeks I've found myself leaving them precariously balanced on the edge of the kitchen counter while chopping the veg, next to the sink while filling the kettle, on the floor while i work above them with tools I might drop, manhandling them and generally throwing them around, lol.

I think if you observe a basic set of rules and procedures with them, especially when they first arrive, and *don't* get complacent about it, then they will be fine.

No offence Kepler, you are way more experienced than I am in these matters, but in some ways I think your experience made you a bit complacent here, and if you'd retained a bit of the same respect you had for them the first time you used LiPo you probably would have caught the problem before it happened.....

Hyena - careful with them horses, they can be a real fire hazard you know:

http://swns.com/firefighters-battle-100-tonnes-of-horse-manure-after-tractor-explodes-271059.html

 

[dogman dan]

Sounds to me like Kepler was not complacent at all, and did nothing wrong at all. Suckers just went up like a bad laptop battery.

But I do agree, keep a bit wary, and don't store this stuff on flamable surfaces. Go buy a few 16x16 tiles, or some tile backer board to make a place to set em down.

 

[knoxie]

:? no no Kepler didnt do nothing wrong here? what i would say is I would not use a new pack like this for testing hall phase combos and would use a current limiting power supply, the fact that the pack let loose was most likely a QC issue with the zippys.

We are all responsible for our own actions at the end of the day, I treat my lipos wit the same respect that I had when I got them and in fact I check them more rigourously now as they are approaching 200 cycle or so, no puffing or any other problems for me, I am and have always used Turnigy packs, they have always been run 2s 2p and my controller is limited to 35A so neither pack has ever seen more than 20A, all this and the shallow discharge and light charge cycle really helps the cells stay in tip top shape.

I think a video would be helpful for newbs, I will get and do one to show folks how I manage and handle my packs.

 

[Ykick]

Could a forensic fire expert determine what actually happened? Perhaps a lab that could go over this evidence and come to a conclusion about the cause? We don't really know what the source of ignition happened to be in this or John's case, do we? Yes, the brick was laying there but did shorting tabs or wiring cause things to go Nuclear?

I understand that it may be impurities but has an expert battery engineer confirmed this could be the likely cause? I would just like to know what a fire investigator thinks after a study of the evidence before jumping to conclusion that it's spontaneous combustion.

I found my disabled oven to be a suitable storage location - also since John's incident I store my bricks around 3.5-3.7V/cell. I figured if there is a fire 'might as well have as little energy available as possible. At lower voltages my 5Ah bricks have only about 1Ah or so remaining as opposed to 3-5Ah at 3.85V/cell and above. Might be hurting longevity to a degree but at over a year and hundreds of cycles I'm not too worried about that anymore...

 

[jonathanm]

The packs wer Zippy 20C packs, brand new, and balance charged on a high end Hyperion charger. This was however their first discharge cycle.

This is what I was talking about...if there was a QC issue, it would probably have been spotted if the packs had been cycled a few times off the bike........seems like complacency to me - everywhere I look that is the standard wisdom....