LiPoly self-combustion - RC Groups
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Feb 01, 2005, 05:50 AM
Thermal Wrangler
DrFragnasty's Avatar
Alert

LiPoly self-combustion


I just bought a LiPoly battery;
PolyQuest 1800mah, 3S; 11.1v
from an online supplier.


I left it on the office desk over the last week, ensuring it
was away from metal, kept cool & out of direct sunlight.

It was a present for my Dad for his 48" Druine Turbulent.

Before leaving for work this morning I smelt burning & traced
it to the battery in the office. The battery was hot to touch,
had melted & burst at the end opposite to the connectors.

I left it outside on cool concrete while at work; it has since stopped
burning but is now a liability to use as well as a potential hazard.

I have dig camera pics of the battery & the scorched desk surface.


I haven't even charged it/ connected/ installed it....it sat there on the desk inert!

Anyone else had similar probs?

It's a very poor $60 firecracker



Chris.
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Feb 01, 2005, 08:00 AM
Registered User
Damaged during shipment?
Feb 01, 2005, 08:29 AM
Registered User
By airmail in the cargo bay of an airliner from the Orient?

- RD
Feb 01, 2005, 08:35 AM
Registered User
I'm going to ask to check the cargo manifest before I fly to or from the Orient again
Feb 01, 2005, 08:36 AM
Registered User
Thank goodness the pack didn't burst into flame and set fire to your home while you were away.

There have been a few reports of LiPo packs that were damaged by pets chewing on them. Do you have a cat that could have jumped up on the desk and gnawed on the end of the pack that is now charred? Fleek is right about damage during shipment being another potential cause.

Some people take great pains to remind us that LiPos don't just burst into flames for no reason, so there is obviously a reason for this. But this does make the point that it's possible for a brand new, unused, uncharged pack to burst into flame for no obvious reason.

This is why so many people recommend always storing LiPos in a location where they can't possibly set fire to anything in the unlikely situation where they just burst into flame for no apparent reason.

Always.
Feb 01, 2005, 09:03 AM
Registered User
Chris,

If you still have the pack, would you mind reporting where the tabs are with respect to the eruption? Some packs bring the wires out on the tab ends, some opposite the tab ends. Thanks -

- RD
Feb 01, 2005, 09:17 AM
Space Coast USA
hoppy's Avatar
Chris,
Please notify the supplier of this pack of the accident.

Do not disassemble the pack. It is dangerous and will impede any possible failure investigation by the manufacturer.

You may receive a replacement and the vendor may want to examine the pack to determine the cause of failure.

Thanks for reporting this incident. This is the first of this kind reported.
Feb 01, 2005, 09:25 AM
Space Coast USA
hoppy's Avatar
This doesn't look like a typical Lipo thermal-run-away battery fire but more like a minor short melting and charring the rubber insulation on the end of the PQ packs. Or it might be that the pack was pretty much discharged and didn't have enough energy left to cause the complete destruction of the pack. Was there any white smoke in the room?
Feb 01, 2005, 09:50 AM
Registered User
Quote:
Originally Posted by abenn
I'm going to ask to check the cargo manifest before I fly to or from the Orient again
I don't think you need to check that, the temperature of the cargo holds in the air can reach -20 celcius and no chemical reaction should happen at that temperature. Just my thoughts, am I wrong?
Feb 01, 2005, 09:52 AM
Registered User
Quote:
Originally Posted by fleek
I don't think you need to check that, the temperature of the cargo holds in the air can reach -20 celcius and no chemical reaction should happen at that temperature. Just my thoughts, am I wrong?
A thought just came across my mind. If the Lipo is not packed properly and condensation develops, could it have shorted the internals?
Feb 01, 2005, 10:09 AM
Registered User
Possibilities abound with deficient packaging:

https://www.rcgroups.com/forums/show...ingsafe+unsafe

BTW, the last shipment I got, this brand of LiPo was well packaged.

- RD
Feb 01, 2005, 10:11 AM
Permanently Banned
Most tabs on factory assembled LIPO packs are bent over and unsulated on the pouch .

I have repackaged most of my packs with tabs away from the pouch and leads hot-melt glued for strain relief and JST center taps installed
Feb 01, 2005, 10:33 AM
Registered User
sneu's Avatar
Quote:
Originally Posted by fleek
I don't think you need to check that, the temperature of the cargo holds in the air can reach -20 celcius and no chemical reaction should happen at that temperature. Just my thoughts, am I wrong?
Most passanger jet cargo holds while not as toasty as the upper deck are heated also--animals are transported all the time and in most cases they don't come out frozen. Don't pretend that just because it is cooler that it makes lithium cells in cargo safer!

Steve
Feb 01, 2005, 04:50 PM
Registered User
landru's Avatar
Chris,

Thanks for posting details of this incident, which serves as a good reminder of the importance of proper lipo storage at all times.

As noted there must be a cause for the incident. I have no intention of guessing the cause of your lipo pack failure, but I would like to share with you an experience I had with a brand new, factory-made pack I purchased last year.

Specifically, I received a 3S pack in which a centre tap wire gave a reading of zero voltage on one cell. The pack had never been used or even charged by me. After discussing the problem with the vendor by email, I decided to have a look inside the pack for myself. My dissection of the pack revealed that the center tap wire in question was completely unconnected to the PCB inside the pack. Looking at the placement of the loose and unisulated wire end inside the pack, I thought it conceivable that the wire could possibly have been moved by handling of the pack, perhaps causing a short with other connections on the PCB. Fortunately, that did not happen, and I was able to repair the pack.

Coincidentally, my faulty pack was also made by same maufacturer as yours.

Andrew
Last edited by landru; Feb 01, 2005 at 04:52 PM. Reason: clarification
Feb 02, 2005, 12:51 AM
Thermal Wrangler
DrFragnasty's Avatar

LiPoly Self-combustion


Hi Guys,

Many thanks for the responses...I'm currently working with the supplier to sort it out. The pack holds 7.1v despite looking like a red boot with the toes worn through

No animal interference & no evidence (external observation) of improper handling on delivery was recorded.

Here's another gruesome photo:


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