karolh

My flying buddy was driving along and had a fully charged 4 cell lipo pack on his car floor when it started making a hissing sound like air escaping from a tyre and shortly after started swelling up, and by the time he was able to throw it outside of his car it started giving off heavy black smoke and burst into flames. I am very aware that lipos can be very temperimental and have to be handled with care but what could have caused this to happen and without them being in use.

I am quite concerned with this occurance as having been a modeler for 40 years firstly with glow and now gas engines, I have just ventured into the electric world and am in the process of building my first electric / foam and balsa model and plan on using a 3 cell lipo battery pack to power the outrunner motor. To say that I am having second thoughts about electric flight is an understatement and I'm hoping that someone can chime in and allay my fears.

Karol

Dialed_In

Normally lipo's are fairly safe from what I've read. Most incidents come from overcharging, over discharging or from damage to the pack. It's also important to have a pack with the proper rating for it's use. Once the pack begins to swell then it's time to safely get rid of it. Lipos should be stored, chargerd and transported in a lipo sack and/or some sort of fireproof container like an surplus ammo box. I guess the idea here is to treat them with the respect that they deserve.

If you want to do a little more reading on lipo care then have a look here. http://www.maxamps.com/lipo-care.php

P.S. I'm glad that your buddy is ok.

Walt Thyng

My Feedback: (9)

Dialed in pretty much covered it. These days it is rare for a LiPo to ignite unless it has suffered some kind of abuse. I still try to observe the old "80%" rule: never exceed 80% of any parameter on a LiPo: charge/discharge rates, capacity.
Walt

sparkola

Was there water on the floormat. A little water across the terminals goes kaboom!!!!!!!

karolh

No water anywhere, it was an all dry senario.

Karol

pilotpete2

What type connector was on the battery? There is always the possibility that something else on the floor shorted the battery connector.
Pete

lorih

This is very interesting. A few things to keep in mind:
1) You can go into any r/c hobby shop around and find dozens, if not hundreds, of lipos on the shelf and hanging on the wall. NO insurance company would allow this to happen if lipos just burst into flames for no reason.
2) Lipos are used in cell phones, computers, GPS units and many other devices. Unless they are being charged by a faulty charger, they don't just burst into flames.

Something happened to that lipo. What? I don't know. A sharp object on the floor? Damaged by dropping or crash eariler? I don't know. We will likely never know, but lipos, from all that I have ever been able to read, don't just puff up and burn with no reason.

The packaging on them is soft to save weight, but this also makes them somewhat fragile.

Maybe you could find some more information about the battery packs condition, history and traveling conditions.

Cliff

karolh

After reading everything you guys posted on this and doing a really thorough post mortem, we have come to conclusion that more than likely the demise of the lipos was due to damage they received in a recent rather violent and unscheduled meeting with terra firma

Karol

cmptrguy

My Feedback: (19)

In response to the put about Lipos being used in other appliances. Not Lipos, but Lithium Ion batteries are used in those units not Lipos-totally different chemistry. A much safer chemistry. But the statement about the hobby shops having them all over the place is very true. I will bet however, that the insurance companies underwriters are not aware the potential the Lithium batteries in general have for extreme energy dissipation.