I'm a Beliver.........Now

[K7SGJ]

A few weeks ago, I was flying my RC heli and having a good time. But, while trying to do some trick shit, I ran it into my inverted vee; full, tilt, boogie. After replacing the obvious FU parts, I just could not get enough power to get any lift. I replaced the stripped gears, rotor blades, and even took a chance on the motors, but no joy. By trying different spare batteries, I was able to eliminate that as a problem. So, I decided to walk away from it for a few days, and left everything on the table where I was working. The table, by the way, happens to be in front of one of the windows that gets the afternoon sun for several hours.

Yesterday, I noticed one of the LiPo batteries had a bulge. Now, these are flat packs that appear to be in sealed silver packs. So, I figured it was just an air expansion from being in the sunlight and heating up a bit. It hadn't looked like that earlier in the day. A normal person would take it out of the sunlight, and leave it the fuck alone. But NOOOOOOOOOOOOOOOOOOOO

I decide to vent it. I just happen to have a sewing needle nearby, and figured a tiny hole would do the trick. So, I put a very little puncture hole in the bag, being careful to not go very deep, for obvious reasons. So after putting this itty bitty hole in the bag, I give it a squeeze, and sure enough, the air escapes, and the battery returns to normal size. End of story? Fuck no.

I see a little wisp of smoke exit the pin hole, and see a microscopic orange glow, and then it goes out. About like an ash falling from a cigarette. I think to myself, huh, that's interesting. I give the pack a little "squeeze" from the sides figuring that would cause the bag to pull away from the spot where I put the hole. Excellent idea, NOT.

The next thing I know, it's like there is a solar flare going on in my hand, and I’m looking directly at the sun through high powered binoculars. Fortunately, I was by the front door and chucked this flaming mass out the door, looking much like a falling star, a very large falling star. It fell onto the driveway, where it reduced the granite pebbles to a state rivaled only by Mauna Loa. At that point the smoke detectors are wailing like the horns in Arkansas during a multi F5 tornado alert, and I am frantically phoning the monitoring service to cancel the slurry bombers that I know have been dispatched to the area.

When it finally burned itself out, the smoke cleared, and the temp had dropped below 4000 degrees C, I was amazed at what was left. It looked like the silver wrapper off a stick of Juicy Fruit gum with a couple of wires attached to it, or perhaps a mini Jiffy Pop container (after having fallen in the campfire for a week or two). It weighed practically nothing compared to a battery in its native condition. I've posted some photos, and can only offer the advice that comes with every battery, is seen on you tube, and is warned by others with a similar experience, and what common sense would dictate:

DON'T FUCK WITH LiPo BATTERIES. This could have been a real disaster, and honestly, I knew better than to mess with it, but........

585858595860

[N8YX]

Hmmm...if we could only get them to initiate on demand...

[KG4CGC]

Hmmm...if we could only get them to initiate on demand...

Dude ... you're scaring me. :wtf::doh:

[W3WN]

Eddie, if you don't mind, I think I'm going to use this in my club newsletter. I will have to edit the language a touch.

[K7SGJ]

Eddie, if you don't mind, I think I'm going to use this in my club newsletter. I will have to edit the language a touch.

No problem Ron, you have my blessings. If you need/want more photos, let me know; or if you need any additional info just ask. Or, if you want the carcass I'll be glad to send it to you for show and smell. You know, after seeing this, I can understand why the USPS is banning the shipment of LiPo batteries through the mail. I'll tell you what, I've been around electronics and electricity for 50+ years, and I have no idea what possessed me to do what I did. I'm very aware how dangerous these things can be. Can you imagine a LiPo pack in in an electric car going TU? And, it is scary when you think about how inquisitive and fearless little kids are, and how they might fool around with one of these, and really get hurt, or worse. It's also very scary when you read about Apple, Dell, and others recalling computers and or chargers because they over heat and can catch fire. After seeing the fireball this little gem went into, I can see how dangerous they can be. I suppose a guy could make a fortune if he could figure out how to build a mini Halon system into these battery packs. Perhaps that's what will happen in the future.

[PA5COR]

We fired .22 LR 's at them at 25 meters for fun, old laptop lipo's which still could hold some charge.
I can vouch for your story as being true 110%.
Thanks for warning us and me reliving the krakatoan fires erupting from the larger cells LOL
to be honest, 25 meters away seems to be too close then...

[n2ize]

First I would be curious as to what type of rc helicopter you are flying ? From the size of the battery it looks like a smaller model. I also fly rc helicopters now and then. The one I fly the most is a 350 size with a single rotor and a large LiPO.

LiPO's are extremely dangerous and volatile. Never ever ever charge them unattended. Several hobbyists have had serious house or car fires while charging them unattended. Puncturing a LiPO is a no no!! as you found out. Even the tiniest pin prick will cause them to short internally and burst into flames. Even if you drop them dent them, or, after a crash it is advisable to put them in a safe place and observe them for a while to make sure nothing is gone wrong. Some LiPO's puff slightly when hot after use or as they get old. This is usually not serious. But, if the battery is puffed up a lot it's best to get rid of it. Short it or puncture it in a safe fireproof place or, dunk it in salt water for a week then chuck it.

I generally store my LiPO's in a heavy fireproof vault when they are not in use. Those batteries scare me. I remember one guy telling me that one of the advantages of electric helicopters over gas or nitro burners is that you don't have to store gas or nitro fuel. Uh yeah... but the LiPO ain't much better. Matter of fact the LiPO is even less predictable.

Far as the lift problem goes, what type of helicopter is it ? It could be the battery wasn't putting out enough power. If the polarity to the motors is correct and the blades are on right and nothing is binding you should get lift. Try a new battery (looks like you have no choice) and see what happens.

[K7SGJ]

First I would be curious as to what type of rc helicopter you are flying ? From the size of the battery it looks like a smaller model. I also fly rc helicopters now and then. The one I fly the most is a 350 size with a single rotor and a large LiPO.

LiPO's are extremely dangerous and volatile. Never ever ever charge them unattended. Several hobbyists have had serious house or car fires while charging them unattended. Puncturing a LiPO is a no no!! as you found out. Even the tiniest pin prick will cause them to short internally and burst into flames. Even if you drop them dent them, or, after a crash it is advisable to put them in a safe place and observe them for a while to make sure nothing is gone wrong. Some LiPO's puff slightly when hot after use or as they get old. This is usually not serious. But, if the battery is puffed up a lot it's best to get rid of it. Short it or puncture it in a safe fireproof place or, dunk it in salt water for a week then chuck it.

I generally store my LiPO's in a heavy fireproof vault when they are not in use. Those batteries scare me. I remember one guy telling me that one of the advantages of electric helicopters over gas or nitro burners is that you don't have to store gas or nitro fuel. Uh yeah... but the LiPO ain't much better. Matter of fact the LiPO is even less predictable.

Far as the lift problem goes, what type of helicopter is it ? It could be the battery wasn't putting out enough power. If the polarity to the motors is correct and the blades are on right and nothing is binding you should get lift. Try a new battery (looks like you have no choice) and see what happens.


This one was a Walkera 5#10. I've had it awhile, and decided to pull it out and fly it around outside. It's kind of a tween. A little big for inside, and a little small for outside. Yes, I've tried all the common stuff, and batteries were the first thing I tried as I have several extras. I think what happened, is when it hit the antenna, it damaged the inner rotor shaft. It's a coaxial unit, and the lower blades seem to spin out okay, but the upper seems very sluggish. At least it seems that way. I am trying another rotor shaft assembly to see what happens. It really acts like what you would expect if the motor gear and drive gear didn't have enough clearance, but that isn't the problem. I'll let you know what it turns out to be.

[WØTKX]

On the other hand, isn't freaking amazing how much energy can be stored in such a small package?

Let's be Careful Out There.

http://blog.discoveroptions.com/wp-content/uploads/2011/03/singing-blues-praises-how-hill-street-changed-tv1.jpg

[K7SGJ]

On the other hand, isn't freaking amazing how much energy can be stored in such a small package?

Let's be Careful Out There.

http://blog.discoveroptions.com/wp-content/uploads/2011/03/singing-blues-praises-how-hill-street-changed-tv1.jpg

It really is. I've had/seen other chemistry batteries short, but it was nothing near this impressive. I can't imagine being around a large industrial size LiPo when it explodes.

[n2ize]

This one was a Walkera 5#10. I've had it awhile, and decided to pull it out and fly it around outside. It's kind of a tween. A little big for inside, and a little small for outside. Yes, I've tried all the common stuff, and batteries were the first thing I tried as I have several extras. I think what happened, is when it hit the antenna, it damaged the inner rotor shaft. It's a coaxial unit, and the lower blades seem to spin out okay, but the upper seems very sluggish. At least it seems that way. I am trying another rotor shaft assembly to see what happens. It really acts like what you would expect if the motor gear and drive gear didn't have enough clearance, but that isn't the problem. I'll let you know what it turns out to be.



It sounds a lot like my old Esky V3 Coax (which is 3 years old, crashed a few times, and still flies). With the coax's any kind of hit generally strips the gears and bends the shafts. On mine it's the outer shaft that usually gets messed up (it figures, it's the more difficult one to replace). But sometimes the inner one will bend and , more often than not...BOTH!! I usually pull them out, take off the gears and roll them on a flat table. Any wobble and they are bent and need to be replaced. i've found even I slight bend can cause considerable power loss, short flight times, and reduced lift. This may sound dumb but of course make sure the right blades are on the right places. One time I accidentally put the top blades on the bottom and the bottom blades on top.

I don't fly the coax much these days and when i do its mostly indoors. Sometimes on a calm day I'll open the window (on the second floor) and starting from inside I'll fly it out the window and then back inside again. One time I flew it out the window, landed it on the patio, took off and brought it back in through the window. Another time a gust of wind blew it straight back in through the window and I crash landed it on a soft bed.

These days I mostly use the single rotor outdoors.

[suddenseer]

Take a piece of solder, and short out an AA 1.5v battery. It will melt the solder before going into thermal runaway. Alot of power in a small package.

[KG4CGC]

Take a piece of solder, and short out an AA 1.5v battery. It will melt the solder before going into thermal runaway. Alot of power in a small package.

Don't tell people stuff like that. You'll get everyone in trouble.

[kb2vxa]

Don't try this at home.
We're what you call... idiots.

[WX7P]

I want to be a "beliver".

[kb2vxa]

Replay it a few times, it'll get to you. http://www.youtube.com/watch?v=LV9VhplCimQ