David weeks Posted February 16, 2021 Share Posted February 16, 2021 OH WHAT A BLOW, THE BIG GUFF FLEW SO NICELY. I SEE THE WEATHER AT B2M IS WARMING UP THIS WEEK, HOPEFULLY SOME NICE FLYING WEATHER FOR YOUR OTHER MODELS. ARE YOU STILL IN FRANCE INVOLANTARILY OR IS THE HOUSE KEEPING YOU BUSY, HOPE WE CAN CATCH UP IN THE SUMMER. I AM PRESENTLY ASSEMBLING A 100 INCH asw28 WITH A FEW ADDITIONS AND MY VIRST VARIOMETER, EVEN THOUGH I THOUGHT THE GUY WITH ONE AT THE CLUB WAS SOMEHOW CHEATING AND DIMINISHING THE SKILL OF CATCHING A THERMAL, WELL I DECIDED TO ENTER THE 21 ST CENTURY !! DAVID WEEKS Quote Link to comment Share on other sites More sharing options...
kc Posted February 17, 2021 Share Posted February 17, 2021 Presumably a smoke alarm would have alerted you to this? Did you have an alarm or does it not work with such fires? Perhaps they are not so common in France as UK...... Quote Link to comment Share on other sites More sharing options...
MattyB Posted February 17, 2021 Share Posted February 17, 2021 (edited) 22 hours ago, Rich Griff said: Thanks Frank and Alan, will read the internet one this evening, this phone will not open pdf files, don't know why. The lads phone does read pdf files. Me Saving hard for a pc or laptop, then landline etc.. That is very strange, I can't remember seeing a phone for years that couldn't open PDFs. No matter; just go to the relevent app store for your phone and download a free PDF reader, there are lots there including most peoples choice, Adobe Acrobat: iOS (iPhone/iPad) - Adobe Acrobat PDF reader Google Play store (Android devices) - Adobe Acrobat PDF reader Once you have that installed the Lipo guide from the BMFA should open straight up... Edited February 17, 2021 by MattyB Quote Link to comment Share on other sites More sharing options...
MattyB Posted February 17, 2021 Share Posted February 17, 2021 On 16/02/2021 at 07:32, David Davis said: ...I know I'm bolting the stable door after the horse has bolted but I have found a source of ammunition boxes and fire-proof/ fire resistant charging bags which I will order directly. George Stringwell has advised me to store LiPos which are not going to be used immediately at "storage charge" levels in a steel box and to charge LiPos outside whenever the weather is suitable. My charger, a Hobby King X120, has a storage charge facility. I am left with with the problem of where to store the ammunition box. My workshop has a concrete floor but there are model aeroplanes and stocks of balsa wood which would go up nicely in the event of a fire as I know from experience. The underground garage is a possibility but there are piles of firewood stored there and a 1974 Rover. The wine cellar doubles as a paint store and is where I chop my firewood. I have a second garage detached from the house made from concrete with an asbestos roof but that contains about ten gallons, (50 litres) of glow fuel! If you store lipos at storage charge levels the chance of spontaneous combustion is nearly zero - the only way that can occur is a direct short caused by internal dendrite growth, but that only really occurs at a rate that would be worrying if stored above 4V/cell. As such I would say any of those locations are suitable providing you follow some common sense guidance: Keep in an electrically insulated metal container (ammo box or similar). I don't use lipo sacks for storage at home, they just don't have the ability to supresss a fire for long enough. Don't put all your lipos in one box, split them into a few containers and separate them within the area you will store them. Always store between 3.7-3.8V/cell (some will argue that in their optinon this does not increase the cycle life of the battery, but what isn't debatable is that it makes them safer in storage - there is far less energy stored if something does go wrong, and dendrite growth will be massively slower reducing the chances of a short). 1 Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted February 17, 2021 Share Posted February 17, 2021 (edited) All this talk of LiPos bursting into flames has prompted me into ordering a smoke / fire detector to add to my burglar alarm system in my wooden log cabin. I've been meaning to do it for a while but not got round to it. Piece of mind if nothing else. menvier_m12_multi-sensor.pdf Edited February 17, 2021 by Gary Manuel 1 Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted February 17, 2021 Share Posted February 17, 2021 I would class a smoke detector in a workshop as an essential. I also bought an extra one for the spare room where I use my 3D printer. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted February 17, 2021 Share Posted February 17, 2021 It’s not just batteries in storage that you need to be careful of. A friend used a lipo in a petrol powered model with a posh receiver that had voltage regulation and an inbuilt switch that allegedly allowed the battery to remain connected with an insignificant drain. He was in his workshop and wondered why his leg was getting warm - looked behind him and the model was on fire... 1 Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted February 17, 2021 Share Posted February 17, 2021 One thing that initially put me off fitting a smoke detector was "false alarms" due to dust / occasional smoke(!) whilst I'm working. Having looked into it, the worst culprits would be the ionisation ones. The one I've ordered uses optical smoke detection plus heat detection. Each of the 4 available modes can be programmed so that I can hopefully find a setting that works well for me. Being fitted to the alarm system, I also have the option of disabling it if I know that I am going to be making smoke. https://www.fireangel.co.uk/the-different-types-of-fire-alarms-and-where-to-install-them/ Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted February 17, 2021 Share Posted February 17, 2021 bad luck there David,sorry to hear about your models,but your ok as is your home etc... ken anderson...ne...1...sympathy dept. Quote Link to comment Share on other sites More sharing options...
Capt Kremen Posted February 17, 2021 Share Posted February 17, 2021 Sorry for your loss David. As Matty points out, providing stored at a correct balanced 'storage' charge state, in a suitable insulated container, little chance of combustion. Think about all our model shops and all their stock including dozens of LiPo just hanging on display in their packets on the wall in many (most?) instances. Their insurers wouldn't cover them if there was a high probability they'd go off while just sat there. How many model shop fires due to LiPo have there been, not counting any mis-managed charging or discharging instances? Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted February 18, 2021 Share Posted February 18, 2021 A terrible loss David, and a real wake up call. If it was me I'd give serious thought to buying another charger. All those that I've used have a time cutout, if the pack isn't fully charged after the maximum time set the charger switches off. Essentially it's telling you that something is wrong and needs attention. If yours chuntered away trying to balance a pack for several hours I'd have second thoughts about using it again. The models can be rebuilt, the main thing is you are still in one piece and have a roof over your head? Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted February 18, 2021 Share Posted February 18, 2021 Good advice Bob. Both my more modern chargers seemingly refuse to balance charge packs if they are significantly unbalanced... GG Quote Link to comment Share on other sites More sharing options...
ColdLazerus Posted February 18, 2021 Share Posted February 18, 2021 As MattyB says dendrite growth seems to be the problem, and as Capt Kremen says we don’t hear of problems with stock in a model shop. The thing is we are talking about used batteries and these are subject to chemical /mechanical change when being charged and discharged, in fact airlines have been forced to ground aircraft for this very reason. So I think the lesson to be learned is to be aware of the all the heightened risks when charging and store safely as is practicable. I personally have a four bay charging station with a modern balance 4way charger and each bay equipped with lipo sacks and chepo “ebay special” temperature sensor/ alarm that can cut off the power above a certain temperature I have mine set to 35c if a battery just gets mildly warm the station shuts down, but I still don’t leave it unattended for any length of time. Installing a different type of fire alarm gona give that a try, this forum is always full of good simple ideas. Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 18, 2021 Author Share Posted February 18, 2021 I shall simply charge LiPos outside as the first step for the time being. I don't think that any of the cells on the rest of my batteries are as divergent as the one which exploded on Sunday. I have been persuaded by multiple sources to build another Big Guff fuselage and tail! It was not a priority but now it is. I'll start a build blog when I get the time. I'm not sure whether to keep the door or not. It's not essential, Charlie Chomos's Big Guff does not have one and his is one of the smartest Big Guff's I've ever seen. What do you think? Guy Auvieux from the club has volunteered to build the tail surfaces. The Nieuport and Fokker DVII are examples of his work. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted February 18, 2021 Share Posted February 18, 2021 get building David, it'll be easier 2nd time as you know all the ins and outs of the build...your model was a nice job. ken anderson...ne..1...get DD building dept. Quote Link to comment Share on other sites More sharing options...
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