The old caution about charging li-polys was recently brought to bear in the Phoenix area when a modeler lost his life in a fire in his shop. The fire department could find no other cause for the fire other than a li-poly battery attached to a charger. The individual was apparently trapped in his shop by the battery explosion, there was only one way out and the battery was between him and the door.
Hi Don,
THANK YOU .... ANY MORE INFO?
Thank you for the post on this tragic event. Do you have any more details on this? A link to a News paper or TV news report, a date, ? TIA
My guess is that there must be more to this story. I don't think the battery alone would be enough to trap a person in the shop. If the battery was anywhere near some flamables, paint, fuel, etc. these items burning could easily trap someone after being ignited by the burning battery.
SMOKE .... 40 SECOND BURN ... GOOD DEMOS, LIPOSACK
The other factor is the smoke! My 17' x 25' shop was completely filled with thick black/gray, foul smelling smoke. I have a very large door that I was able to open to the outside so there was never a safety issue.
Fortunately, our batteries do not explode like a bomb, they burn rapidly, very much like a large flare does. Our 4S batteries burn for approximately 40 seconds, roughly 10 seconds per cell. Fortunately for us they usually go off with the "bad" cell 1st, then it ignites the next cell, etc. I do not mean it is an organized burn, it is very sudden, and very messy with a LOT of smoke and ash.
Please go to this link to see several excellent demos of LipoPacks burning:
http://www.liposack.com/video.htmI highly recommend using these Liposacks. I have used them for the past few years in ERC. I have posted this here before but it is worth repeating. These are excellent products. They are not made from simple Nomex material (Nomex would fail/melt at our temps.) they use a very expensive material used by NASA. Here is the link to buy them:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&P=SM&I=LXSEA5Another option is using small ceramic planter boxes from Home Depot (or equivalent home center). They are in the garden section. I have posted photos of mine here in the past. They are perfect for our ECL size batteries.
REAL LIVE DEMO YESTERDAY!
Strange that this post came up now because I just watched a 3S battery "go off" yesterday. I was flying both ERC and ECL at our electric field. A guy saw his battery PUFF UP during charge, then did the correct thing and removed the swelled up battery and put it in a safe place on the cement parking lot. (I would have liked to see him place it a little farther from his truck, than 5', but it worked out OK). I turned to see the battery "go off" about 10 min. after it was placed there. The flames were approx. 30" high and wide for a few seconds, then down to a smaller burn as each cell went off. Being outside in the wind, the smoke dissipated quickly. Several of the guys still charge their batteries on their cars, using the cars 12V battery. IMHO this is a NO NO, but it is hard to get modelers to change. :-(
THE "GOOD, THE BAD, AND THE UGLY"
BTW: He was using an inexpensive (red) battery. I agree 100% with Mike Palko, saving money on cheap batteries is "PENNEY WISE AND POUND FOOLISH!!!!" I use Thunder Power Batteries that are assembled here in the USA (LV NV :-). They are high quality batteries with excellent customer service. FlightPower also makes very high quality batteries. There is a large drop off in quality below these two top name brand batteries. ..... IMHO: If you can get the same V/Amps battery for 1/2 price, something is wrong with that battery for our use! The top two name brands above use very high quality cells combined with careful assembly. I trust Thunder Power batteries in my small 4S ECL planes and my larger 10S ERC planes.
RARE EVENT!
Fortunately for us: THIS ACCIDENT IS A VERY RARE EVENT! Properly treated, our batteries are very safe. As I have said before on this list, I have over 1,000 E flights and friends with thousands of E flights, with only ONE burned battery. And that was caused by a faulty charger many years ago.
GREAT CHARGER .... TP 1010
I use the Excellent 1010 charger from Thunder Power because it has the "feedback" loop that stops the charge if there are any problems. I also always use a balancer during the charge. I hope that more charges in the future combine this loop, and the balancer into one single unit. The trend seems to be in this direction. :-)
There are many things we can do to make our charging safer but here are a few that I think are important:
A FEW SAFETY TIPS
1. ALWAYS PLACE BATTERIES ON A CERAMIC TILE
Our batteries burn at 2,000 degrees F for a few seconds. This will "weld" the battery to the tile, which also melts around 2,000 degrees. This will prevent most fires and save your bench, table, home, etc. from going up in flames. Any tile from a Home center is OK, and very inexpensive. I have my charging table coated with all tan tile. My wife thinks it "looks" better too! ;-)
2. NEVER CHARGE IN YOUR CAR, OR IN YOUR ENGINE COMPARTMENT!
Please use a table next to your car if you have to use your auto 12V battery. It is better to use a separate 12V battery like Mike and I do. It is much safer!!!
3. HAVE A WINDOW/DOOR TO THE OUTSIDE "OPEN" WHILE CHARGING!
The smoke is terrible, it needs to get out ASAP
4. ALWAYS USE A "LIPOSACK" or SAFE CONTAINER
Please see above for LipoSack info. Or use ceramic container, ammo box, etc. with VENT holes to release the pressure.
5. ALWAYS USE A BALANCER
And a charger with a feedback loop if possible.
6. AVOID "CHEAP" BATTERIES ... FALSE ECONOMY!
Trust Mike Palko, he knows what he is talking about when it comes to ECL! :-)
Sorry for the long winded post, but I think E power is the future of modeling and it would be nice if we all used it safely. There are a lot of modelers out there who are strongly against using E power in CLPA so we need to make sure we don't give them any ammunition to fire against us. ;-)
PS: Don, call me if you need help at your CL Speed/Combat contest. :-)
Regards,