Gemma Jane Posted February 17, 2009 Share Posted February 17, 2009 Hi, well it might sound daft but what does a LiPo actually look like when it puffs? I hear the term all the time but have never seen a picture or found an explanation of how to recognise it. Is it the outer wrapper that puffs up or the inner cells? Confused of Essex who is wondering if one of her cells has gone puffy after it was accidentally discharged at too high a rate Also is there any test to tell if the cell has had its day? I have gleaned that puffing is due to chemical changes in the cell, so I assume one could test the fully charged voltage and now if a cell was at the end of its life? Quote Link to comment Share on other sites More sharing options...
Bert Posted February 17, 2009 Share Posted February 17, 2009 Gemma There's (an out of focus) pic of one HERE If your lipo is puffed don't use it - it's not worth it Bert Quote Link to comment Share on other sites More sharing options...
Gemma Jane Posted February 17, 2009 Author Share Posted February 17, 2009 I got a forbidden message when I tried the link Bert. It's the outer surface under the wrap, it is usually hard but has gone sort of squiggy - I just want confirmation that it is actually puffed as I've got dozens off them yet have never seen it before - if so I shall dispatch it to the lipo graveyard Quote Link to comment Share on other sites More sharing options...
Bert Posted February 17, 2009 Share Posted February 17, 2009 Ah yes, you probably have to be signed in to RCGroups to see it. If the plastic bag is inflated a bit so that you can compress it, it is puffed. Try THIS ONE Bert Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted February 17, 2009 Share Posted February 17, 2009 Thats jolly puffed Bert Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted February 17, 2009 Share Posted February 17, 2009 gemma-treat the thing with care-as they are dodgy when they are swollen(puffed)i have seen a one go off-they can do a lot damage to anything/one in the close proximity best discharge totally-put a couple of slit's in the pouch's-drown them in salt water for a couple of hour's-bingo one dead /safe lipo that can be disposed of with normal waste ken anderson................................ i Quote Link to comment Share on other sites More sharing options...
Gemma Jane Posted February 17, 2009 Author Share Posted February 17, 2009 Well it is nothing like Bert's picture, but it is different to other identical packs I have, so I'm taking no chances and have wired it up to a 12V auto bulb and left it to discharge in the garage away from anything that could combust. I shall then carry out the slicing and drowning ritual. Thanks for the help Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted February 17, 2009 Share Posted February 17, 2009 Gemma, very important according to my club electric is devils work so make sure you have a cross near the dying lipo so that ythe devil is suitably demised Quote Link to comment Share on other sites More sharing options...
Gemma Jane Posted February 17, 2009 Author Share Posted February 17, 2009 Will do Stephen It sure is the work of the devil. I've finally sat down and put together a spread sheet utilising much of what Timbo has said on the forums and other bits and pieces I've gleaned regarding LiPo 'C' ratings and other such trickery from the internet. It's odd really, with it all laid out in front of me for each of my batteries, I sort of look at it and think, "that isn't actually that difficult - in fact it is sort of obvious" - it only took me two years to get around to it though Hopefully then not too many more LiPo burial rituals will be needed and the devil can be kept at bay... though I guess a visit from the devil might liven up an otherwise dull and miserable Monday afternoon. Quote Link to comment Share on other sites More sharing options...
joshua jones Posted February 17, 2009 Share Posted February 17, 2009 Hi Gemma, Well at least it is fortunate that you have a few other lipos to use and that it wont stop you flying. Out of interest can i ask what type of lipo was it, brand capacity etc and how long you have had it and what it was used for. I collecting relvant data of this type. Either post here or your very welcome to pm me. Thankyou, Josh Quote Link to comment Share on other sites More sharing options...
Gemma Jane Posted February 17, 2009 Author Share Posted February 17, 2009 It was a Thunder Power 3s 2100 15C Josh, I have a number of them that have given great service in my modified HZ Cub with brushless motor. Unfortunately I was bench testing a different model that I had not intended to use the battery for and I rather over cooked it. Nothing to do with the battery, entirely my fault. After discharging it I've no doubt now what puffing is, it was like a melon, hubby was sent to the top of the garden to stab it and drop it in a jar of salt over night. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted February 17, 2009 Share Posted February 17, 2009 gemma-make sure all your door's and window's are locked in case the lipo has'nt been killed properly(stabbed) ken anderson........................................... Quote Link to comment Share on other sites More sharing options...
Gemma Jane Posted February 17, 2009 Author Share Posted February 17, 2009 I'm going to have nightmares now about it coming to get me in the middle of night Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted February 17, 2009 Share Posted February 17, 2009 Youll have no problems Gemma the 10 feet high and 8 feet wide cross a neclace of Garlic and hubbie chanting all night by the backdoor holding a brushless in each hand will do the trick Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted February 18, 2009 Share Posted February 18, 2009 I had one catch fire in a model once, the model survived but what an inferno! Quote Link to comment Share on other sites More sharing options...
Terence Lynock Posted February 19, 2009 Share Posted February 19, 2009 Found the perfect disposal site for a duff Lipo, they were just laying the concrete base for my garage so it is now under 18 inches of reinforced concrete!.. get out of that if you can Lipo!... regards, Terry Quote Link to comment Share on other sites More sharing options...
Terence Lynock Posted February 19, 2009 Share Posted February 19, 2009 I had one catch fire in a model once, the model survived but what an inferno! What was the model Mat, a bloomin tank?..... regards, Terry Quote Link to comment Share on other sites More sharing options...
winchweight Posted February 19, 2009 Share Posted February 19, 2009 Disposing of a lipo safely is easy and safe to do. Just fill a bucket or container with saltwater and pop in in. Do it outside to be on the safe side, but there's no need to stab it or anything. Leave it for 24hrs, remove and check the cells are dead with a voltmeter, and dispose of as a normal battery in your rubbish. That's it. Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted February 19, 2009 Share Posted February 19, 2009 It was an all moulded speed 400 pylon racer, itno which I stuffed a brushless motor and LiPo, trust me it's quick . The front 5" of the fuz burned away and needed re-moulding, can't tell now. Quote Link to comment Share on other sites More sharing options...
Rick Tee Posted February 20, 2009 Share Posted February 20, 2009 Quote from Lithium wikipedia: Lithium metal is flammable and potentially explosive when exposed to air and especially water, though it is far less dangerous than other alkali metals in this regard. The lithium-water reaction at normal temperatures is brisk but not violent. Lithium fires are difficult to extinguish, requiring special chemicals designed to smother them (see sodium for details). Does placing a LiPo in salt water cause the lithium to burn off even if the pack is not punctured? Quote Link to comment Share on other sites More sharing options...
Bert Posted February 20, 2009 Share Posted February 20, 2009 Placing the pack in salt water allows it to discharge at a slow, safe rate. There is very little lithium in a lipo cell which is why the flames don't last very long when they burn. After they have been fully discharged there is practically no fire risk and they can be placed in the normal household rubbish for disposal. Bert Quote Link to comment Share on other sites More sharing options...
winchweight Posted February 20, 2009 Share Posted February 20, 2009 No it doesn't burn off. It allows the pack to be rendered fully discharged and otherwise inert. Don't forget this is Lithium Polymer, (as Bert says small quantities of lithium) and not straight lithium, which I agree is very nasty stuff. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 20, 2009 Share Posted February 20, 2009 The salt water soaking is nothing to do with combustion - it is merely to finish off discharging the cells completely - salt water as you probably know is a reasonably good conductor of of electricity. The correct method of LiPo disposal ( as mentioned many times on the forum, and covered extensivel elsewhere, including my recent article in the mag ) is to dischrge the pack using a car headlamp bulb or similar, until a meter shows 0V, in other words completely "flat". Then , if possible, carefully slit along the seams of the pouches of each cell, immerse in the salt water for say 24 hours or so - then bin it. Quote Link to comment Share on other sites More sharing options...
Jon Posted February 20, 2009 Share Posted February 20, 2009 Here is a pic of my £110.00s worth useless of puffed Lipo, it only flew twice Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 20, 2009 Share Posted February 20, 2009 Actually thats NOT LiPo puffing / swelling - it looks a lot like physical damage to me. Puffing from internal overheating almost always affects the whole case along its length and both sides with a distinct springy "puffiness" or swelling - this definately looks like crash damage to me. Quote Link to comment Share on other sites More sharing options...
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