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Sep 10, 2004, 06:23 PM
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Lipo reality check,,,,my turn!


Did a stupid thing last night, talking on the phone while swapping different combinations of lipos while doing amp checks on a motor.

I plugged a 2s1p pack into a 'Y' harness allready connected to a 3s1p pack.

While I was talking I could hear a sound like styorfoam squeeking (the pack expanding), just then I saw a slight whiff of smoke come the battery tray, by the time I grabbed the packs it had exploded into a fierce fire ball, I couldn't get to my fire extingusher because the burning pack was between me and it so I just let the pack burn itself out. It filled the entire place with smoke and a layer of fine black ash.

It was a bit of a reality check but a good lesson, I now know what a lipo smells like before it goes up, I also have reviewed the location of the extiguisher in my workshop and although I thought I was allways carefull I got sloppy,, go over each action in your head before doing it.

Joe

Pic of the 'Y' harness with wires but burnt off pack.
Pic of burnt pack, straight through vinyl tiles.
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Sep 10, 2004, 06:28 PM
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vintage1's Avatar
yers. I don't have any special housing apart from a couple of ceramic pots I stick the lipos in when charging, but I am incredibly careful (so far) to see that everything is plugged togeher right..
Sep 10, 2004, 06:33 PM
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Now, imagine being on a highway full of speeding cars driven by people talking on their mobile phones .....

Glad the only damage was to your pack.
Sep 10, 2004, 07:07 PM
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Thread OP
We've been in a bad drought, but since last night it's been raining all night and it's still pelting down now,,,,, must have been the little 'dance' I did around the burning pack trying to get away

On a serious note, if one of these things went off in our car, you would have to bend over and kiss ya bum goodbye,,, it just happens too quickly and too intensly to do much about it.

Vintage in on the right track, a flame proof charging container and carry box, I used a steel sheet about 2 foot square but after seeing how far the burning pack gets sprayed it would be next to useless.

Joe
Sep 10, 2004, 11:09 PM
Registered User
I also did a stupid thing recently with a lipo.

Was getting ready to check amp draw and battery voltage for a new motor/prop/battery combo. Got out my "wattmeter", which is a 50A/50mv shunt with dedicated cables, and the two DVM's needed to take the readings. Hooked the battery up first, then put the bannana jacks in the DVM's. Hmmmmmm. No voltage reading. Uh oh. UH OH, the cables are getting HOT!!!! Unplugged everything in a near panic, and took the battery outside on the patio to cool down. It was 120F when I got around to checking it.

Turns out, I plugged one of the battery voltage read jacks into the unfused 10 amp shunt in the DVM. A short circuit. At least there was about 10 feet of 18 gage wire in the circuit to up the resistance. Battery seems to be fine. There is tape over the 10 amp shunt jack on both DVM's now.
Sep 11, 2004, 01:39 AM
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Close one
Joe
Sep 11, 2004, 01:55 AM
PGR
PGR
Low AltiDude
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Quote:
Originally Posted by Joe41
Vintage in on the right track, a flame proof charging container and carry box, ....
Just a note on the carry box issue ..

I can't believe how many people show up at the flying field with dark-colored steel boxes full of batteries. A half-hour in the sun and those boxes become a solar oven. I'm comfortable carrying my batteries (LiPos included) in my flight box but if I was to use a carry box, it would be gloss white.

Pete
Sep 11, 2004, 03:02 AM
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vintage1's Avatar
I have polarised plugs in everything so I can't plug things in wrong.

I carry the packs to the field one at a time in my pocket. Its only a 50-100yd walk from the back door
Sep 11, 2004, 04:04 AM
Registered User
Thread OP
All my plugs are polarised, whether, they are micro deans, normal deans, JST type or astroflight zero loss type and yes I carry my lipos in my flight box with all my other stuff,,, yep in my car,,, at highway speeds even,,, but once you experience a lipo venting with flame it make you think that little bit more.

I probably will get some sort of metal charging/carrying box and yes I'll probably paint it white or I can just use my explosives magazine carry box and cross out the EXPLOSIVES DETONATORS and change it to EXPLOSIVES LITHIUM CELLS.

At the moment I feel more consious about my Lipos than I do about my blasting gear,,, gee I hope one of them don't go off unexpectedly!,,,,touch wood

Joe
Sep 11, 2004, 05:32 AM
WAA pilot #21
Vanning's Avatar
just dont carry the lipo AND the blasting gear at the same time!
Sep 11, 2004, 06:57 AM
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dave morris's Avatar
My number one rule is to not talk to anyone while charging/connecting lipos. If they insist I just stop what I am doing until I can give all my attention to the task at hand.
Sep 11, 2004, 09:29 AM
Cal
Cal
How long do ya think it will be before manufactures make these Lipos "idiot proof", cause at one time or another, we all become idiots every once in awhile, even if it's only for a fraction of a second ??
Sep 11, 2004, 09:54 AM
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Aio_1's Avatar
Quote:
Originally Posted by Cal
How long do ya think it will be before manufactures make these Lipos "idiot proof", cause at one time or another, we all become idiots every once in awhile, even if it's only for a fraction of a second ??
Very true.

Take all the precautions you can to avoid the mistakes but most of all take care that when or if you do make a mistake it won't be catastrophic. If you fry a battery or some equipment you'll get over it. What you might have more difficulty getting over is the loss of a car, house or conceivably even a life.

Aidan
Sep 12, 2004, 06:04 AM
WAA pilot #21
Vanning's Avatar
Confucious said something to the effect "the wisest man knows how little he truly understands".
Applied to me that would read "It would be really smart to assume i'm gonna screw something up".
Based on that assumption, i charge them on the concrete patio outside. Next to my fire extinguisher. No worries except for a $50 battery.
Sep 12, 2004, 08:36 PM
Registered User
Joe, I dont think ill get you to send that to me for experimentation!
Glad you weren't hurt.

Adam


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