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HomeAircraftHelicopterSafety - RC Helis are not toys › Aint no joke!!.......LIPO Hazard!!
12-07-2004 04:57 AM  13 years agoPost 1
cp8

rrApprentice

Buckeye State

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Well, here is the correct topic to place this. Read it and Weep......with me! You'd think Kokam would put a temp. cut off on their cells or something !

http://www.runryder.com/t145370p1/

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12-07-2004 06:18 PM  13 years agoPost 2
scoot

rrNovice

Hampshire, UK

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Nearly all LiPo fires are caused by the "users", wrong cell count, wrong cell type, over discharged, etc etc etc

If treated right LiPos are just as safe as any other cell. This sort of thing puts people of trying LiPos as they dont understand its down to user errors.

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12-09-2004 02:39 PM  13 years agoPost 3
longbow

rrNovice

Westminster, Maryland

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Yes I agree and look at the charger as well. Those are usually the cause. Just use the supplied chargers and wait the extra time and you will be fine..I have flown Duralites for over a year now and they are great if you follow the directions....

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12-09-2004 02:54 PM  13 years agoPost 4
cp8

rrApprentice

Buckeye State

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If you read the post you will see that I was using a Triton charger (not the Double Vision in the pic) which is designed to charge this type of battery. However, I had it set incorrectly.

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12-09-2004 03:53 PM  13 years agoPost 5
BigChopper

rrKey Veteran

Cambridge, UK

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Do you guys with duralites take them out of your heli when you charge them?

It must be a bit of a hassle, when strapped onto the radio tray?

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12-16-2004 01:52 AM  13 years agoPost 6
BlakeMcBrayer

rrElite Veteran

Georgetown, Ky

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I always take my lipos out of my Shogun (use velco on tray & pack along with a velco strap). It is alittle bit of trouble, but if I lose a pack to fire, I don't lose the heli too.

This is also why I bought a lipo only charger. I use the quite & simple Kokam 402 charger with their secondary saftey device. The 402 auto detects cell count, so all you have to do is pick a charge rate.The secondary saftey device goes between any charger and pack. It will interupt charging if the voltage goes over a certain voltage. Mine will cut out at 12.6 volts for 3 cells. It will work with any brand of charger.

Look on FMA's site, in their store, under chargers. At the bottom of the page you will see the Saftey Guard. I think it's a heck of an idea. It could have saved your bird!

https://www.fmadirect.com/site/fma.htm?body=Store

Don't come off the throttle untill you see your GOD!

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12-16-2004 04:06 AM  13 years agoPost 7
TMoore

rrMaster

Cookeville, TN

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Might I suggest an ammo box?

TM

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12-16-2004 04:18 AM  13 years agoPost 8
CACTUSJACK (RIP)

rrApprentice

State of Confusion

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Might I suggest an ammo box?
That's what I use, better safe than sorry.

.

X5X7 Animum Vestrum Negotium Agatis

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01-15-2005 03:06 AM  13 years agoPost 9
jerrythercpilot

rrVeteran

--South Florida --

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I use the Astro 109 for the lipolies. I have a Triton too but feel safer with the Astro as it's "automatic" provided it recognizes the number of cells correctly

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01-15-2005 06:54 PM  13 years agoPost 10
B52fixer

rrApprentice

Oklahoma City, Oklahoma, USA

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That must suck that's why I only charge my batts ouside of the bird!!
Sorry for your loss.

A word to the wise ain't necessary. It's the stupid ones that need the advice.

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01-15-2005 07:34 PM  13 years agoPost 11
Raffy

rrElite Veteran

Chicago, Illinois

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Do you guys with duralites take them out of your heli when you charge them?
For safety, I do take them off the heli. I use Duralite's Lipo charger that I monitor while charging for approx. 6 hrs. I don't mind the hassle because one charge can give many flying time.
Quick chargers can create a Hazard if you don't pay attention to details specially if you own a variety of Lipo cells.

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01-15-2005 10:30 PM  13 years agoPost 12
Rick_H

rrKey Veteran

Boulder City, Nevada

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The Triton is a great charger and can safely charge LiPo's if used correctly. The Triton has an optional Temp sensor that sould always be used when charging Li type batteries. if set correctly it will shutdown the charger if the battery starts to get too hot which will prevent things like this.

Rick

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03-23-2005 10:29 PM  13 years agoPost 13
Pbusch OLD

rrNovice

Minnesota

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Hey at least you still got the tail.

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03-24-2005 12:24 AM  13 years agoPost 14
Ace Dude

rrProfessor

USA

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If treated right LiPos are just as safe as any other cell. This sort of thing puts people of trying LiPos as they dont understand its down to user errors.
If you believe that then perhaps you really don't understand the safety features that are incorporated in many of the other cell types. Ever wonder why there are far more Li-Po fires than any cell type of fire? Perhaps they're really not as safe safe as you think. How many people store/charge their Ni-Cad, Ni-Mh, Li-Ion cells in an Ammo box, Brinks box, Sentry Safe, or Battery Bunker?

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03-24-2005 01:25 PM  13 years agoPost 15
CRAZYKEV

rrVeteran

Cincinnati,Oh - U.S.A.

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Use the correct charger and they are very safe. They just take closer attention and care, but if everything ids done correctly, then they are very safe.

Kevin

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04-28-2005 12:28 PM  13 years agoPost 16
Rainman

rrNovice

Watford, UK

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I hate to burst anyones bubble but until recently I was also of the opinion that correct charging and safe levels of discharge would mean safe LiPo operation.

I've been flying with LiPo for around two years now and I've always had great success and no dramas. This March I finished building a Composite-ARF Extra 2x2 which has an AXI 5330/18 outrunner turning a 20x11 prop. The recommended prop is actually a 20x13 for FAI use and the motor is rated to 60 amps. It is powered by 10S3P 6000mAh TP cells which are rated well over 60 amps discharge. The configuration of motor and prop was only pulling around 35amps WOT static. I've had maybe half a dozen 12 minute flights and was only putting around 4000mAh back into the cells with my Schulze ISL 6-330d charger. Packs were always charged as two 5S3P packs and then reconnected in series for flight - they were always recharged within a dozen mAh of each other with a difference of no more than 0.1volts between the packs when discharged and fully charged.

I let a friend of mine have a fly of this model and about 2 minutes into the flight he found he no power whatsoever and landed the model dead-stick. Once on the ground he opened the throttle to see if it would power-up and suddenly the model was engulfed in thick white smoke. We happened to have a CO2 extinguisher on hand and unloaded the whole thing straight into the front of the model until the fire was out. Consequently there was very little damage and the model remains remarkably unscathed.

One set of 3P cells had caught fire. The outer cells had both ignited but the one on the inside had not. I put a voltmeter across this cell and found that it only read 3.0 volts. I suspect that the outer two cells had been making up for the loss in available current and had cooked themselves into oblivion.

So, be warned, you don't have to mis-charge a lithium cell to start a fire - they can catch fire during discharge.

Phil

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05-07-2005 10:54 PM  13 years agoPost 17
Rainman

rrNovice

Watford, UK

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Not sure how that will help - even charging at 1C can take over an hour and a half once you've allowed for the ramp-up and ramp-down phases of the charge. You may not get cells with a full-charge.

Also, no lamp timer will save you from an incorrectly setup charger, which would appear to be the cause of most LiPo fires and indeed is the point of the original post. I would suspect it takes less than 1.5 hours for most LiPo cells to "go up" if charged as a NiMh.

I would imagine that it's quite easy to build something to disconnect power to the charger if the cells get too hot. You could have a thermacouple connected to a relay - place thermacouple next to the cells to detect excessive heat and it opens a relay or switch in between the power source and the charger. It would be quite cheap to build. Trouble is, for it to work properly you'd need a device for every set of parallel cells in the pack. If it's just a 1P set of cells then it would work great - for stuff like shock-flyers and indoor helis.

Phil

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07-07-2005 10:09 PM  12 years agoPost 18
NickWaanders

rrNovice

Vancouver, BC - Canada

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Years ago when I was into RC cars, I had a charger that had a thermo-cut-off. Worked great! Until the day I was in a hurry and forgot to put the little thermo thing on the battery. It didn't have a timer as well, it was just a straight hi-power nicad charger. It toasted the battery, and left a nasty smell in the room I was charging it in

I guess the best solution is still to be around when you charge the battery.

I charge my lipo's in a fire safe container, with a smoke detector right next to the crack in the lid. Not sure if this will be safe enough, I haven't actually blown a lipo up yet. I can just hope.

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HomeAircraftHelicopterSafety - RC Helis are not toys › Aint no joke!!.......LIPO Hazard!!
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