meltdown

rwoynaro · 04-13-2015, 05:39 AM

My older I2 had a meltdown ! The rear battery "vented" (you could see greasy residue and the case was warped) and it melted the connector on the board. Ouch. No visible flames or smoke outside when it happened. Dang.

Tritium · 04-13-2015, 11:55 AM

Was this as you were riding it?
Was it plugged in?

MTOBATTERY · 04-13-2015, 12:09 PM

Ouch is right! I have always thought the small vent in the battery was not of sufficient design but I have never seen proof like this. I sincerely hope nobody or nothing (other than the Seg) was damaged when this occurred. It may be worth a call to your homeowners insurance to see if you can get some compensation. For my own curiosity, did this happen while charging or while riding?

For disposal, you should be able to take that battery to your local solid waste authority to have it properly disposed of. Even though I would certainly like to think the battery has no more energy left in it I would personally leave it outside to air out for a few days. If you have to transport it inside an enclosed vehicle you can use a 5 gal bucket. Place the battery in a plastic bag and seal as best you can. Put approx 2" of vermiculite in the bottom of the bucket and then place the battery in keeping it centered in the bucket. Proceed to fill the bucket with vermiculite insuring that at least 2" of vermiculite is around all sides of the battery. Place the lid on the bucket and you are complete. This is the safest possible way to handle one of these batteries in the event of a catastrophe like this. Vermiculite can be purchased at the blue and orange hardware stores and most garden centers.

Good luck!!

Gihgehls · 04-13-2015, 01:05 PM

I thought that these batteries used chemistry that was not subject to thermal runaway because they didn't produce oxygen when they vent. How could this failure have occurred?

MTOBATTERY · 04-13-2015, 01:29 PM

Quote:

Originally Posted by Gihgehls

I thought that these batteries used chemistry that was not subject to thermal runaway because they didn't produce oxygen when they vent. How could this failure have occurred?

Compared to other lithium chemistries these cells are less dangerous. The bottom line is that lithium iron phosphate cells can still hold a large amount of energy so when something does fail they have the potential to produce a fair amount of heat to dissipate that energy. If you wire directly to the cells in a Segway you could weld 1/8" steel with this battery. No lithium battery is safe but some are certainly less dangerous than others.

Amimoto · 04-13-2015, 03:35 PM

I can almost guarantee it's water submerged damage causing the thermal runaway.
As I had seen 3 cases so far with identical damage.
Will provide photo upon request, looks pretty similar to rwoynaro's.

Sent from my iPhone 6 using Tapatalk

dale@thecoys.net · 04-13-2015, 03:37 PM

Quote:

Originally Posted by Gihgehls

I thought that these batteries used chemistry that was not subject to thermal runaway because they didn't produce oxygen when they vent. How could this failure have occurred?

This does not appear (to me) to be "thermal runaway". As Jason indicated, there was clearly an event that expended a large amount of energy (heat), but it didn't involve nearly all of the energy available in that battery. Therefore, no "runaway".

The good news is that there was no fire involved.

Amimoto · 04-13-2015, 04:08 PM

when submerged in water or water find its way into the battery casing, The thermal runaway started from the moisture on the BMS causing short circuits, subsequently carbon deposits start to build up, and the carbon deposit will starting to short circuit the battery nickel plates, at the same time the area of carbon build up increases, more cells starts to release heat from the short circuits........

Sent from my iPhone 6 using Tapatalk

Amimoto · 04-13-2015, 04:26 PM

Because the workshop is on the 8th floor and we were unable to remove the Segway to outdoor (no balcony), Intervention was applied on the soaking wet Segway when black smoke developing, the battery was removed and cut open the casing on 3 sides, force open the top casing and cut the individual charging cables to the BMS, break connection to the connectors and isolate two modules on this particular case.
Other 2 cases we only received the dead machine with end result very similar to rwoynaro's.

Sent from my iPhone 6 using Tapatalk

Gihgehls · 04-13-2015, 04:58 PM

Nasty! Thanks for the photos Animoto.

04-13-2015, 12:09 PM	#3
MTOBATTERY Member Join Date: Jan 2008 Location: York, PA Posts: 644	Ouch is right! I have always thought the small vent in the battery was not of sufficient design but I have never seen proof like this. I sincerely hope nobody or nothing (other than the Seg) was damaged when this occurred. It may be worth a call to your homeowners insurance to see if you can get some compensation. For my own curiosity, did this happen while charging or while riding? For disposal, you should be able to take that battery to your local solid waste authority to have it properly disposed of. Even though I would certainly like to think the battery has no more energy left in it I would personally leave it outside to air out for a few days. If you have to transport it inside an enclosed vehicle you can use a 5 gal bucket. Place the battery in a plastic bag and seal as best you can. Put approx 2" of vermiculite in the bottom of the bucket and then place the battery in keeping it centered in the bucket. Proceed to fill the bucket with vermiculite insuring that at least 2" of vermiculite is around all sides of the battery. Place the lid on the bucket and you are complete. This is the safest possible way to handle one of these batteries in the event of a catastrophe like this. Vermiculite can be purchased at the blue and orange hardware stores and most garden centers. Good luck!! __________________ Warm Regards, Jason Abel Battery Builders / MTO Battery

04-13-2015, 01:05 PM	#4
Gihgehls Senior Member Join Date: May 2006 Location: Galactic Sector ZZ9 Plural Z Alpha Posts: 2,086	I thought that these batteries used chemistry that was not subject to thermal runaway because they didn't produce oxygen when they vent. How could this failure have occurred? __________________ To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts. "...if you insist on being imprecise in use and unique in definition, you should hardly be surprised that your attempts at communication are poorly understood." -a wise man

04-13-2015, 04:08 PM	#8
Amimoto Member Join Date: Sep 2012 Location: Taiwan Posts: 195	meltdown when submerged in water or water find its way into the battery casing, The thermal runaway started from the moisture on the BMS causing short circuits, subsequently carbon deposits start to build up, and the carbon deposit will starting to short circuit the battery nickel plates, at the same time the area of carbon build up increases, more cells starts to release heat from the short circuits........ Sent from my iPhone 6 using Tapatalk Last edited by Amimoto; 04-13-2015 at 05:24 PM..

04-13-2015, 04:58 PM	#10
Gihgehls Senior Member Join Date: May 2006 Location: Galactic Sector ZZ9 Plural Z Alpha Posts: 2,086	Nasty! Thanks for the photos Animoto. __________________ To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts. "...if you insist on being imprecise in use and unique in definition, you should hardly be surprised that your attempts at communication are poorly understood." -a wise man

04-13-2015, 11:55 AM	#2
Tritium Member Join Date: Jun 2013 Location: Tucson Posts: 792	Was this as you were riding it? Was it plugged in?

04-13-2015, 03:35 PM	#6
Amimoto Member Join Date: Sep 2012 Location: Taiwan Posts: 195	I can almost guarantee it's water submerged damage causing the thermal runaway. As I had seen 3 cases so far with identical damage. Will provide photo upon request, looks pretty similar to rwoynaro's. Sent from my iPhone 6 using Tapatalk

04-13-2015, 04:26 PM	#9
Amimoto Member Join Date: Sep 2012 Location: Taiwan Posts: 195	Because the workshop is on the 8th floor and we were unable to remove the Segway to outdoor (no balcony), Intervention was applied on the soaking wet Segway when black smoke developing, the battery was removed and cut open the casing on 3 sides, force open the top casing and cut the individual charging cables to the BMS, break connection to the connectors and isolate two modules on this particular case. Other 2 cases we only received the dead machine with end result very similar to rwoynaro's. Sent from my iPhone 6 using Tapatalk

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