ICE-MAN Posted June 21, 2013 Share Posted June 21, 2013 Just a heads up on a new battery bunker very shortly to become available: BL-LiPoBN Quote Link to comment Share on other sites More sharing options...
Olly P Posted June 21, 2013 Share Posted June 21, 2013 Hmm - looks like a catering aluminium food tray to me..... Quote Link to comment Share on other sites More sharing options...
Simon B Posted June 21, 2013 Share Posted June 21, 2013 Spot on. It's been adapted slightly, but it's definitely one of those with some holes cut in it. Quote Link to comment Share on other sites More sharing options...
ICE-MAN Posted June 21, 2013 Author Share Posted June 21, 2013 Yes exactly. Laser cut holes and two sliders to lock the lid on, and limit external fire. (Stainless steel, not aluminium) Edited By ICE-MAN on 21/06/2013 10:23:30 Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted June 21, 2013 Share Posted June 21, 2013 I know the debate about the safety of LiPos rages on but I have a definate concern about placing a high power battery in an highly electrically conductive box for "safety". If something does go wrong with the LiPo what are the chances that the battery conductors end up shorting on the box greatly increasing the risk of a catastophic LiPo failure. In a low risk situation adding further safely features may actually contribute to the overall risk. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 21, 2013 Share Posted June 21, 2013 Yet another scarey video to push sales of bain-maries LOL I have never used any sort of bunker or bag whilst charging Li-Pos ( and I have done a fair few thousand over my time ) I would prefer to be able to observe the process, and if charging multiple packs, which I almost always do, then if one goes wrong, the damage spreads to others if in enclosed containers. Use a clever charger, double check the settings and wires etc, and never leave completely un-attended. If field charging, keep the process away from vehicles and others etc. Simples..... TAKE CARE. Quote Link to comment Share on other sites More sharing options...
ICE-MAN Posted June 21, 2013 Author Share Posted June 21, 2013 I take your point, but I've tried to make a LiPo battery burn by shorting it out, without success. I'm not saying it can't happen but when I tried, the solder inside the battery melted and disconnected the wires. Quote Link to comment Share on other sites More sharing options...
Olly P Posted June 21, 2013 Share Posted June 21, 2013 Posted by ICE-MAN on 21/06/2013 10:47:19: I take your point, but I've tried to make a LiPo battery burn by shorting it out, without success. I'm not saying it can't happen but when I tried, the solder inside the battery melted and disconnected the wires. Still making the Battery unusable, when it would have been fine without being placed in a metal box. Sorry, I'm not sold on this idea, I'll stick to setting things up correctly, and keeping an eye on the lipos as they charge. Quote Link to comment Share on other sites More sharing options...
kc Posted June 21, 2013 Share Posted June 21, 2013 What does that do that a biscuit tin does not? Biscuit tins tend to be airtight too. I would have thought a ceramic insert with a Lipo size recess that would go in any tin would be a more useful product. Quote Link to comment Share on other sites More sharing options...
Olly P Posted June 21, 2013 Share Posted June 21, 2013 Airtight would be a bad thing - it will allow the pressure to build and eventually go pop - if the battery was big enough.... Quote Link to comment Share on other sites More sharing options...
kc Posted June 21, 2013 Share Posted June 21, 2013 OK what does it do that a biscuit tin with a hole in it cannot do? Actually some people carry lipos in airtight biscuit tins whilst in their car. Do you have a better method? Quote Link to comment Share on other sites More sharing options...
Olly P Posted June 21, 2013 Share Posted June 21, 2013 I have an aluminum instrument case, fully lined with foam. I put the batteries inside a plastic case within this. job done. Neither is sealed, Lipo's can't short as all female connectors. Quote Link to comment Share on other sites More sharing options...
ICE-MAN Posted June 21, 2013 Author Share Posted June 21, 2013 Burning Lipo's can get to very high temperatures. I wouldn't be too happy with aluminium. Quote Link to comment Share on other sites More sharing options...
kc Posted June 21, 2013 Share Posted June 21, 2013 An Aluminium instrument case would be fairly airtight? But if it were not airtight wouldn't the smoke from any foam that caught fire make fumes even worse if driving the car? I considered lining a tin with a ceramic tile and some plaster at the sides, and a loose tile on top. Maybe plaster to separate each Lipo. Does that sound a good idea? A friend had a Lipo catch fire whilst in his car boot at the field. Not charging or even connected to a plane, we though he probably twisted the wires inside the lipo whilst handling it previously.. Anyway as he was standing near the open boot lid he managed to throw it out of the car without further damage. Quote Link to comment Share on other sites More sharing options...
Olly P Posted June 21, 2013 Share Posted June 21, 2013 ICE Man - what would cause the Li-Po to go into thermal run away? I manage my Lipos carefully, charge on a piece of heat proof kitchen tile, and observe during charging process. I then transport them inside a double layered carry system, with the rest of my field equipment so nothing will pierce the sides, and they have female connectors so cannot short on each other or the case. The only remaining cause of thermal run away would be if I left the case in direct sunlight or a hot area. Given I transport the lipo containing case generally in the passenger footwell of the car, to prevent the case damageing the aircraft in the back, if it is warm I'll have the blowers on my feet, and if anything did hapen I pull over open the passenger door and throw the case out! I am still struggling to see where such a device has an application, and how a properly cared for Lipo will enter thermal run-away. Quote Link to comment Share on other sites More sharing options...
Olly P Posted June 21, 2013 Share Posted June 21, 2013 Kc- no, not at all airtight - this one is from some old lab equipment belonginng to a previous employer, he was going to skip it. The case is not a 'flight case' type, but more to protect the test gear from damage when stored/carried. Quote Link to comment Share on other sites More sharing options...
ICE-MAN Posted June 21, 2013 Author Share Posted June 21, 2013 Ceramic is a very good material. Ceramic melting point : around 1,000 to 1,600 C Stainless Steel mleting point: starts to melt at around 1,400 C Aluminium melting point: 660 C LiPo fires can get up above 1000 C A tin with ceramic tiles sounds a good way to go provided there's a way for the gases to escape, ie some holes drilled into it otherwise you have a bomb. This is the problem, you need holes to vent the pressure but you also don't want fire to escape - or at least try to limit that. Not much you can do about the obnoxious gases. (Note that LiPo's generate their own combustion gases, so there wouldn't be so much point in putting them in an oxygen free enviornment). Quote Link to comment Share on other sites More sharing options...
Olly P Posted June 21, 2013 Share Posted June 21, 2013 Posted by Olly P on 21/06/2013 12:45:53: ICE Man - what would cause the Li-Po to go into thermal run away? Quote Link to comment Share on other sites More sharing options...
ICE-MAN Posted June 21, 2013 Author Share Posted June 21, 2013 Posted by Olly P on 21/06/2013 12:45:53: ICE Man - what would cause the Li-Po to go into thermal run away? I manage my Lipos carefully, charge on a piece of heat proof kitchen tile, and observe during charging process. I then transport them inside a double layered carry system, with the rest of my field equipment so nothing will pierce the sides, and they have female connectors so cannot short on each other or the case. The only remaining cause of thermal run away would be if I left the case in direct sunlight or a hot area. Given I transport the lipo containing case generally in the passenger footwell of the car, to prevent the case damageing the aircraft in the back, if it is warm I'll have the blowers on my feet, and if anything did hapen I pull over open the passenger door and throw the case out! I am still struggling to see where such a device has an application, and how a properly cared for Lipo will enter thermal run-away. This is a very tough question, you can see stories on Internet where fires start wtih no aparant cause, ie not even while charging. I'm sure in tens of thousands of cases most people will not have a problem, but the issue is the uncertainly, ie the fact that no one can really answer your question about how the fire starts. Hence it's just a matter of playing it safe and mitigating the risk. Just look at the recent Dreamliner issue with thieir batteries. With all the funding they must have to find out definitively what went wrong. I'm sure they've now made other changes, but they also have the batteries in a steel box. Also regarding the charges, is it really the case that these can never go wrong? A dodgy charger and you're in trouble too. Quote Link to comment Share on other sites More sharing options...
ICE-MAN Posted June 21, 2013 Author Share Posted June 21, 2013 Posted by Olly P on 21/06/2013 12:55:10: Posted by Olly P on 21/06/2013 12:45:53: ICE Man - what would cause the Li-Po to go into thermal run away? To force a battery to go into thermal runawy you just need to NOT adhere to the very strict way these batteries need to be charged (of course properly handled by a good charger, a mix between constant voltage and constant current amongs other things). For example I burned up a 3s Lipo by supplying a constant 12v to it with a 5A current limit. You can also trigger it simply by puncturing one of the cells, as you can see here Edited By ICE-MAN on 21/06/2013 13:13:42 Edited By ICE-MAN on 21/06/2013 13:16:08 Quote Link to comment Share on other sites More sharing options...
Olly P Posted June 21, 2013 Share Posted June 21, 2013 Ice- I didn't say these can never go wrong, but I am there monitoring them, if they do I can and will deal withit. Nothing happens for 'no reason' and if I read it on the internet doesn't mean it is true. I know people don't like to publish there own mistakes, and will sometimes not tell the full story (often this is not deliberate...) I would submit that while your product does look reasonably well made and put together I will not be spending what I judge to be a large amount of money on a solution to a problem which I do not feel exists. Proberly cared for, well maintained batteries, stored in a sensible manner to not 'sontaniously burst into flames/explode/run round the house screaming - unless something occurs to start them. Yes Dreamliner is having some issues with Batteries but I do know some of the Tech Team working on them (I went to Uni with them) and they believe the problem lies in the charging and storage regime the batteries have been subjected to, the steel case is actually a side effect of the main solutions. Finally - I don't think it is a tough question, where in my regime is the root cause of a lipo going into run away? Quote Link to comment Share on other sites More sharing options...
ICE-MAN Posted June 21, 2013 Author Share Posted June 21, 2013 Posted by Olly P on 21/06/2013 13:14:35: Finally - I don't think it is a tough question, where in my regime is the root cause of a lipo going into run away? It's a matter of what each individual feels comfortable with. In your regime I admit you should not have a problem, and I don't see any root cuase, but I would be only 99.99 % sure of that. (I should say I would only be 99.99% sure that you won't have a battery catch on fire) Edited By ICE-MAN on 21/06/2013 13:35:03 Quote Link to comment Share on other sites More sharing options...
Jonnor Posted June 21, 2013 Share Posted June 21, 2013 Roll on Graphene batteries -- theyre going to change the world....or so I read. Smaller, more powerful and definitely not potential fire bombs. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 21, 2013 Share Posted June 21, 2013 Quote ICE-MAN "you can see stories on Internet where fires start wtih no apparant cause" Ice Man - I would love a link to these, where a LiPo can be seen spontaneously combusting all of its own accord, not being charged, connected to anything, and stored in a proper environment. Please share some of them with us. Edited By Tim Mackey on 21/06/2013 13:46:02 Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 21, 2013 Share Posted June 21, 2013 Posted by Jonnor on 21/06/2013 13:41:51: Roll on Graphene batteries -- theyre going to change the world....or so I read. Smaller, more powerful and definitely not potential fire bombs. A spare petrol can is a potential fire bomb - IF USED INCORRECTLY. Quote Link to comment Share on other sites More sharing options...
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