christopher small Posted January 3, 2008 Share Posted January 3, 2008 It won`t be long till they are in mobile phones(if they are not already)then even I might be using them.I have heard of them for powering laptops.Perhaps I should get one for my Early Bird,is it right that for the same mAh capacity they are nearly half the size.My old nicad pack is too big to secure properly. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 3, 2008 Share Posted January 3, 2008 Mobile phones have been using Lithium batteries for at least 10 years, and laptops too.For the same capacity, a Lithium battery will be much lighter, but as for size...well this varies from brand to brand. Quote Link to comment Share on other sites More sharing options...
christopher small Posted January 3, 2008 Share Posted January 3, 2008 Whats the difference between a Li ion and a Li Po,I have a Li ion in my hand held amateur radio . Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 3, 2008 Share Posted January 3, 2008 Lithium Ion uses a different chemistry, and is normally packaged in more robust container.Li-ion also has a slightly lower voltage per cell, and is heavier per m/ah. Quote Link to comment Share on other sites More sharing options...
christopher small Posted January 4, 2008 Share Posted January 4, 2008 Thanks Timbo I wondered what the difference was. Quote Link to comment Share on other sites More sharing options...
Tom Foreman Posted January 6, 2008 Share Posted January 6, 2008 No problems yet with my LiPo's have 3 off 2s1p & 3 off 3s1p, only started back in September so havn't used them that much probably only put about 20 cycles on 2 of the 2s1p's at the most. I do use a dedicated balance charger, which is virtually fool proof and my ESC's are LiPo compatible as well so I guess that helps. Cheers Tom Quote Link to comment Share on other sites More sharing options...
Phil Claridge Posted January 7, 2008 Share Posted January 7, 2008 i have two 3s 2200mah 15c lipos used to power two cheap bell outrunners in a twinstar.they cost £22 each from planenutz,so far ive worn out three sets of motors .lipos still good they have never been balance charged, Quote Link to comment Share on other sites More sharing options...
Phil Claridge Posted January 7, 2008 Share Posted January 7, 2008 ps with good use of throtle and thermals they will keep it flying for 30mins+ Quote Link to comment Share on other sites More sharing options...
Graham King Posted January 7, 2008 Share Posted January 7, 2008 I tried several electric planes. Tried the cheap and nasty lipo's from the bay of E - no good - didnt last very long, tried some Tornado 3200's in an Acromaster - one failed after only about 20 flights. Sent back to Overlander who very kindly replaced it with a 3700, now the other 3200 has decided to give up the ghost. None of these batteries have been run at anything close to their limits and always charged with a good lipo charger and then balanced. Given up with battery power now - gone back to good old glow. Sounds better too! Whoever heard of a warbird whistling? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 7, 2008 Share Posted January 7, 2008 Jets do. Quote Link to comment Share on other sites More sharing options...
Tom Foreman Posted January 7, 2008 Share Posted January 7, 2008 Well my Gemini roars past on WOT, it echoes off the factories behind me, sure is a lot of prop noise! Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 7, 2008 Share Posted January 7, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Chris Hornby Posted January 9, 2008 Share Posted January 9, 2008 Dunno if this is relevant but I was taking a 1700MaH 20C 3s lipo out of one of the booms of my Bronco and it started fizzing and giving off clouds of smoke. As I was in my office at the time, I threw it outside (boom and all) and it shot a sheet of flame out of the side. If it wasnt actually an explosion, it came close! see:http://domains-20.com/459up5m9i3r/flights.htm Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 9, 2008 Share Posted January 9, 2008 Yes but do we really know WHY it started to ignite? It's my guess that it must have had some sort of short on the power leads, or even the balancer wiring, cuased perhaps by straining, or contacts crossing etc. Perhaps there was some physical damage? I just cant see that it is going to simply spontaneously combust without cause, the fact that it was sitting there minding its own business and NOT "fizzing" shows that your distubing things started the problem, and if indeed it WAS a shorting out or faulty wires /insulation or similar....then ANY electrical battery could have caused a similar ignition and subsequent fire. I am not meaning to sound critical here Chris, just illustrating the facts. PS sorry to hear about the loss of the model PPS the picture title says it was a 2000 mah pack, NOT a 1700 ? Quote Link to comment Share on other sites More sharing options...
Chris Hornby Posted January 9, 2008 Share Posted January 9, 2008 Timbo It was definitely me disturbing it, I was peeling it off the Velcro, must have distorted it or something. It wasnt connected to anything, there was the balancing connector and a female Deans connector. It was a bit of a tight fit, so I wont do that again. I like electric Flight and this wont put me off. I was just trying to illustrate that it is possible to get careless with Lipos through familiarity.At present I am putting together a YT Stuka, and using 6S 6000MaH pack. That would be a firework display, I guess, so I will have to be careful!Sorry it was a 1700, must have been thinking about something else! As for the model, Only one boom is damaged, and I have got another complete Bronco powered by 2x OS30 FSThanks for the constructive commentsChris Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted January 9, 2008 Share Posted January 9, 2008 Chris Just out of interest, where do you store your Li-Po's?David Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 9, 2008 Share Posted January 9, 2008 Around at Myron's place Quote Link to comment Share on other sites More sharing options...
Chris Salomon Posted January 9, 2008 Author Share Posted January 9, 2008 ROFL! Quote Link to comment Share on other sites More sharing options...
Chris Hornby Posted January 9, 2008 Share Posted January 9, 2008 David Actually I have been storing them in the planes, hanging from the ceiling of my office. They are all coming out now!I am coming round to the opinion that when I stressed the battery, an internal connection (that silver paper stuff) must have shorted.Chris Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 9, 2008 Share Posted January 9, 2008 The only Lipos that I ever leave in an airframe are the small capacity 2s radio packs in my 2 slope soarers....just because they are a pig to get out, forming as they do part of the required nose weight.These are only ever slow charged (.25C ) which is 300m/a, and only then whilst I am in attendance.I know I should really take them out and put them in my Lipo safe when not in use, but I just have not got room for them all anymore ( 50+ packs in total now ) Quote Link to comment Share on other sites More sharing options...
Andy Ramsay Posted January 18, 2008 Share Posted January 18, 2008 To date I have only had one swollen pack, a very old 1st generation 2s 10c pack. I have lost count of the number of flights with this and similar generation packs. As would be expected performance is nothing to write home about but then again I am a slowie golden oldie and happy to potter around the sky.I regard shorts as the biggest danger we face and have shorted two batteries, one a LiPo and the other a Li-Ion, with completely different consequences. The most recent was a LiPo, reverse connection to ESC, which naturally blew the controller but also wrecked the middle cell of the 3s battery. Stupidity, but no dire consequences other than to my pocket. The other was several years ago with a first generation 2s 1200maH Li-Ion fitted with a small BEC type plug which I always struggled to grip and disconnect. After testing an installation I removed the battery and laid it aside. On smelling burning I checked the battery to find it intensely hot and the pins bare and touching. I had obviously pulled on the wires and not the socket and pulled the pins from the mounting. I immediately separated the cause of the short . As I pondered my next move I noticed the end start to glow and was then almost deafed by a violent explosion which left my ears ringing for half an hour. These Li-Ions were encased in thin metal with open ends and the effect was that of a shotgun cartridge. To cut a long story short I ended up with a very expensive insurance claim for scorch marks on a carpet due to the shower of intensely hot filmy debris ejected from the open end but very fortunately escaped injury. The point of the Li-Ion story is that the battery continued to self destruct even after the cause of the short was removed, presumably thermal runaway. I would imagine the same would be the case with a LiPoly except that the battery would combust rather than explode as with the Li-Ion? In spite of these experiences I will still continue to use LiPos but try to take the precautions as outlined in the safety leaflets which accompany batteries when purchased. My own home grown precautions are to always charge with the battery sitting in a metallic container placed on a large ceramic floor tile. I store and transport batteries in plastic containers inside steel cash boxes which can sometimes be purchased cheaply, especially if the retailer has lost the key. The cash boxes are placed inside a large metal document box. However I am human and still make mistakes as evidenced by my recent wrong polarity error.Apologies for the over long post but hope the content is relevant. Quote Link to comment Share on other sites More sharing options...
Chris Salomon Posted January 18, 2008 Author Share Posted January 18, 2008 I think my point, when launching this thread, has been proven, as far as the horror stories of explosions when charging have effectively been killed dead by the application of balancing chargers and a healthy dose of common sense!Long live the Li-po! Quote Link to comment Share on other sites More sharing options...
Erfolg Posted January 18, 2008 Share Posted January 18, 2008 What ever happened to exploding Ni Cads?I remember them well, complete with photographs and warnings regarding the toxicity of the cadmium.Apparently if you leave your tin can (remove baked beans first) and sulphuric acid cell on the bench to long the bottom will rot out. The resulting puddle could easily dissolve your pet dog!Any comments or personal experience.Erfolg Quote Link to comment Share on other sites More sharing options...
Andy Ramsay Posted January 18, 2008 Share Posted January 18, 2008 Echo comments regarding balance chargers. Greatest thing since sliced bread. Have rejuvinated several old discarded OOB packs.No experience of sulphuric acid cells but familiar with the explosive effects of baked beans. Quote Link to comment Share on other sites More sharing options...
Tom Ruut Posted January 19, 2008 Share Posted January 19, 2008 Hey Andy,did you eat the baked beans before they exploded? Quote Link to comment Share on other sites More sharing options...
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