Chris Salomon Posted January 1, 2008 Share Posted January 1, 2008 Firstly, happy 2008 everybody, I've already had my first flight this year, and a maiden at that! Right, a bit of a survey here, I was wondering, with the pretty widespread use of balancers/chargers and the much better knowledge we have of lipo's now, does anyone have any recent knowledge of any exploding/igniting lipo's?I'm not saying we can be complacent about their usage but is it time we started thinking of them differently, with less trepidation? Personally I've not had any scares with them, I've had a couple die after quite a lot of charges but nothing dangerous. Quote Link to comment Share on other sites More sharing options...
winchweight Posted January 1, 2008 Share Posted January 1, 2008 1 swollen pack, that's it. Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted January 1, 2008 Share Posted January 1, 2008 1 x swollen pack about 2 years ago. I'm using Li-Po's now almost daily and feel that as long as they're handled sensibly and charged properly then there's nothing to worry about. If they were as deadly as some folks have convinced themselves then there would be a model shop going up in smoke every week. Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 1, 2008 Share Posted January 1, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Bruce Richards Posted January 1, 2008 Share Posted January 1, 2008 Just lost a cell one one of my 3s 2100mah 20c packs. Never over discharged and never drawn more than 30A. Had about 15-20 charge cycles at 1C never put back more than 75% to reach full charge. The other pack I have is the same and is still going. I also have 4 2s 900mah 15C packs about the same usage all fine. Bruce Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 1, 2008 Share Posted January 1, 2008 In over 4 years of totally Lipo use, and approx 50 various packs now in the garage, have had just 1 pack swelled due to me leaving it connected after flight. Just binned it, and moved on. Stop worrying you lot, be careful ( as with any fuel ) and get modern - you will not regret it. A Biased Tim. Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 1, 2008 Share Posted January 1, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
christopher small Posted January 1, 2008 Share Posted January 1, 2008 I`m sticking with Nicads for now.I had a Nicad pack move forward into my motor in a bad landing,shorting out the motor and battery.Battery survived,motor didn`t ,Smoke pouring out,but just saved it,what would happen with a LiPo? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 1, 2008 Share Posted January 1, 2008 With a Lipo you would have learned by then to do a proper job of installation, in order to prevent that from happening in the first place. Any flight battery should ALWAYS be properly secured to prevent that sort of incident, a small piece of velcro stuck to the pack is useless in most cases, and they should be firmly and completely strapped in place, with protective material in any space between the battery and motor. Fear of something bad happening through misuse/abuse of any equipment is no reason to not embrace the new technology. I seem to remember folks had similar concerns about most developing technology over the years. Your anaology is akin to saying " I will stick to diesel powered cars, as they are less likely to explode in a bad crash than a petrol one ". A petrol powered car which exploded on impact has not been designed /built correctly.PS. I dont see how the motor was destroyed by it having being "shorted out" - this would in effect render it isolated from any damaging high currents, and the full force of the battery would simply be expelled through the battery /ESC wiring, upon which something will probably melt, and the circuit be effectively switched off. The sort of currents which can be let loose from a large Nickel battery is more than enough to cause a fire in certain circumstances. Quote Link to comment Share on other sites More sharing options...
winchweight Posted January 1, 2008 Share Posted January 1, 2008 I have a lipo in my FF9 and was charging it the other day at the field. Blimey, the reaction from other modellers because I had a lipo in my tx was unbelieveable, it was as though I had uttered the name Jehovah! Suddenly there were tall tales of exploding tx, tx which heated up and popped off the battery covers and screws! All unsubstantiated I might add, and all from people who surprised me at their reluctance to accept change. I guess I am trying to say, there's a lot off tall stories about lipos, but if you treat them with care, never run them too low and always charge with an approved charger, you'll be fine. That said I never charge my lipos in doors and would never leave them unattended, not even for a moment. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 1, 2008 Share Posted January 1, 2008 No I never charge in doors either, but sometimes I do charge them inside a building LOL Quote Link to comment Share on other sites More sharing options...
christopher small Posted January 1, 2008 Share Posted January 1, 2008 I have now done a proper job insulating the leads on the capacitors on the motor,put polystyrene blocks between motor and battery,but accidents will always happen however carefull you are.I drive a diesel car,having said that we had a LandRover go on fire,Turbo over heated igniting oil around it and burnt through the fuel line,(burnt right out) Quote Link to comment Share on other sites More sharing options...
Chris Salomon Posted January 2, 2008 Author Share Posted January 2, 2008 I'm with you on this Tim, best thing since etc. etc.You do raise one interesting quandary though, as you say, put protective material in any space between battery and motor, there is a balance between protection and ventilation. Generally it is the last place you want to block up with lumps of foam etc! I tend to do a 'halfway house' approach, shock absorbing material up to halfway up the pack but maintain a through flow of air, at least to one side of the pack.Shaun's fellow flyers' reaction to him using li-pos is exactly what I was getting at with this thread, everybody has heard the tales of fires etc but whether anyone has had first-hand experience, and, more to the point, in the more recent past with balancing chargers etc. I certainly don't know of anyone. All I know is, for the same weight I get twice as long in the air Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted January 2, 2008 Share Posted January 2, 2008 There's no smoke without fire is there ? 'nuff said . Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 2, 2008 Share Posted January 2, 2008 No, and there's no fuel which cant catch fire either. As for insulation, I personally never find my packs getting anything but warm, as I tend to use them at maximum half of their claimed C rate. I have, on one early model, hollowed out a blue foam block which allowed airflow, but still acted as safety barrier. Chris, glad to hear you have taken on board the advice, ( didnt realise you were still on brushed motors ! ) and good luck with the flights Quote Link to comment Share on other sites More sharing options...
Chris Salomon Posted January 2, 2008 Author Share Posted January 2, 2008 Do they still make brushed motors?!! The thing with ventilation is it is usually the same route through the model that cools the battery and the esc, now that is one thing I try to keep as cool as poss, especially if I am running at reduced throttle settings. What we need is an esc shaped like a WW1 radial cylinder or something! Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted January 2, 2008 Share Posted January 2, 2008 "Do they still make brushed motors?!!"Yes, but I was hard pushed to find a brushed ESC recently! Quote Link to comment Share on other sites More sharing options...
Chris Salomon Posted January 2, 2008 Author Share Posted January 2, 2008 You can have all my old ones if you want them! I'm never going to go back to them. The efficiency of brushless along with their lack of weight (and dead cheap now) mean there is just no contest. Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted January 2, 2008 Share Posted January 2, 2008 they still have their occassional uses but generally speaking agreed. Quote Link to comment Share on other sites More sharing options...
Doug Ireland Posted January 3, 2008 Share Posted January 3, 2008 Seems to be a lot of pampering going on here, "brushed motors" "brushed ESC", it'll be combed tail feathers next! Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted January 3, 2008 Share Posted January 3, 2008 Doug As long as these "new tech 'lectric" folks don't ban real established fuels like oil ,petrol,diesel,methanol ,that we've all learnt to live with for many a year (there'no way I would install a lipo in my car .Would you ? even if it weighed 4 oz Whoops sorry I meant to say approx 100 grammes )) & all my tail feathers are made of out of date wood probably from Equador ( there I go again being environmentally open to abuse )If only balsa wood was lighter to transport, it would reduce my "carbon footprint"! Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 3, 2008 Share Posted January 3, 2008 Myron, when are you going to make a post that DOESNT condemn electric flight? I think we all know by now that it is not your thing, but it wont go away you know One day, cars will be fuelled by something potentially far more dangerous than a LiPo, how about a crude hydrogen bomb ? You have obviously been scared off the new technology by silly scare stories, many of which are put about by people who have no knowledge of any real incidents, and those genuine incidents which have been recorded, have always been found to be the fault of the operator. If same "operator" was to try warming his hands on a cold winter day down the field by igniting some of his glow fuel as a camp fire, and the whole lot destroyed his models et al, would you blame the fuel ? Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted January 3, 2008 Share Posted January 3, 2008 Timbo I'd say he had money to burn ! Try living in a camper van All things are based on self sufficiency as my ex's etc live in relative luxury .& Ive learnt not to leave the gas on or run out of water etc. etc .as advocated by our fastly increasing nanny type state & I'm not suffering from the latest problem- obesity -.(spend my money -you know where ! )By the way my mobile cant be repaired & I've a funny feeling its got one of your favorite batteries in it Quote Link to comment Share on other sites More sharing options...
Tom Sharp Posted January 3, 2008 Share Posted January 3, 2008 My sat nav has got a lipo in it. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 3, 2008 Share Posted January 3, 2008 Blimey Tom, you better get a hazard sticker sorted out quick !!And dont forget the disclaimer speech to any prospective hitch hikers, especially Myron Quote Link to comment Share on other sites More sharing options...
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