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Post by fiddlefly on Apr 24, 2011 16:24:43 GMT 1
I know everyone knows of warnings, but how seriously you take these warnings about Lipos could save your house from burning down or your plane.... I have been flying 3 months , and I heeded all the warnings (bought a lipo safe bag, I don't charge while car is moving, make sure to store it in open area, not near heat ect ect)... but as proof of how unstable these batteries are. This morning was getting ready to fly, and I am not kidding nor exaggerating... ALL I did was push the battery into the battery holder for my Super CUB LP and BANG! explosion, smoke fire... If I did not pull it from the battery case right away, say goodbye to my plane. attached is the pic. It makes me mad that the industry has made it standard to use these things knowing they are so unstable... I mean nothing was hooked up and it just explodes? Also read this article from our local flying club... TAKE HEED especially if you are new to the hobby! Article: www.sefsd.org/index.php?option=com_content&view=article&id=135:playing-with-fire&catid=51:general-interest&Itemid=98FF Attachments:
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Post by flydiver on Apr 24, 2011 16:48:21 GMT 1
Never crashed it? Never dropped it?
Even stuffing it into a tight space or pulling on the wires to get it out (Cub @#$%W# battery box anyone?) can cause damage and subsequent shorts. They are NOT in a steel can. The foil pouch provides little protection. Even what seem to be minor impacts and abuse can do damage. Treat the like eggs.
In some ways I'm surprised there are not more reports like this. Some of my buddies are simply nasty to these things and don't seem to EVER grasp the risks this is creating.
You get a dead short in of those things >>>>>WOW! That's probably what happened. Since the bottom end is blown out I suspect some sort of damage down there. Stuffing a fully charged battery into the box may have set off some prior damage.
Lipos are great for power-to-weight, and now power to price ratio. Unfortunately they do have their dangers and learning curve for folks is extremely variable. My rule of thumb is newbies will ruin about a half dozen lipos before they figure them out.
Your only alternative is A123 LiFe or go back to NiMh. A 123 is a pretty good alternative. MUCH more stable and abuse proof but at a weight and power cost on small planes. On planes > 3# the larger 2600mA version is pretty good. I've used the smaller 18650 (AA size) 1100mA variety in smaller planes. Check them out if this has put you off lipo.
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Post by Dillzio on Apr 24, 2011 17:09:18 GMT 1
The stock super cub battery does not fit in the stock battery compartment, it was only a matter of time really before someone's wire's got stripped and ended up arcing together.
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Post by fiddlefly on Apr 24, 2011 18:29:28 GMT 1
Your only alternative is A123 LiFe or go back to NiMh. A 123 is a pretty good alternative. MUCH more stable and abuse proof but at a weight and power cost on small planes. On planes > 3# the larger 2600mA version is pretty good. I've used the smaller 18650 (AA size) 1100mA variety in smaller planes. Check them out if this has put you off lipo. could you explain to a newbie about what a A123 even is? How would I go back to Nimh With the stock setup... would that require redoing anything? I would love an alternative than this happening again... I have a feeling you are right... Not enough room, stuffed it in there, the bottom got cut on some plastic and poof. Thanks! ff |
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Post by fiddlefly on Apr 24, 2011 18:30:29 GMT 1
I've used the smaller 18650 (AA size) 1100mA variety in smaller planes. Check them out if this has put you off lipo. Also some info on this AA size that you speak of too? |
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Post by flydiver on Apr 24, 2011 19:03:46 GMT 1
Fairly rough learning curve since they are not standard. The cells were developed for tool packs. There is a lot of do it yourself involved. www.hobbyking.com/hobbyking/store/uh_listCategoriesAndProducts.asp?catname=LiFePo4&idCategory=218&ParentCat=85www.wattflyer.com/forums/showthread.php?t=26602How to build-this is the larger D-cell size but the concept is the same. www.rcgroups.com/forums/showthread.php?t=599316For NiMh you just get a 7 or 8-cell pack appropriately sized, put the proper jumper back in for LVC and go for a disappointing flight. The 8-cell performs almost decently but fits the box about as well as the lipo (sucks). supercubclub.proboards.com/index.cgi?board=ts&action=display&thread=988www.cheapbatterypacks.com/?menu=DB8377C8EC&sid=876177Cheapbatterypacks also makes A123 packs. Expect them to cost 2-3x as much as lipo. Since the initial starting voltage is a bit lower you generally have to jump up a cell to 4S for equivalent of 3S. The Cub is a proprietary ESC and the LiFe is non-standard voltage so you will run into trouble with the LVC. It's a pain to switch between chemistry types due to difference in LVC for all of them. Watch your connectors-the EC3 on the Cub is only 1 of several different options. I also don't think a 4S square A123 pack will fit a stock battery box so you'll be modifying it. Chances are if you had done that to start with the stock box this accident might not have happened if the repetitive forces of placing/removing it from the stock box did this damage. The Cub has a handful of flaws and I've always contended that the battery box is pretty much top of the list. It took a fair while to dig out info about these batteries and sort it out. If you think you want to go there, start digging. Then I had to get them, then make packs. Frankly I don't bother anymore. I suspect the reality is you won't be willing to do the work for LiFe/A123, and you won't like the performance hit of NiMh. Your 3rd option is to lump it, go back to lipo, and stay cautious. What happened in a way is OK. You are out a few $$, no more, and your red flag now waves wildly. You'll be careful. |
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bloodboughtchad
Flight lieutenant
Super Cub LP... Packing Tape... Glue... Fingers Crossed & Ready for Fun!
Posts: 55
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Post by bloodboughtchad on Apr 25, 2011 15:44:00 GMT 1
Dude that's scary. Did your plane burn?
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Post by fiddlefly on Apr 25, 2011 22:32:43 GMT 1
No, because I reacted and yanked it... but it easily could have.
It ticks me off! How can the industry make these the "Standard" and they are so dangerous?
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Post by renard80 on Apr 25, 2011 23:27:27 GMT 1
Thank you for posting this warning, fiddlefly. These things are like lethal weapons!  As said above, HZ are providing batteries which are too small for their battery box, with no warning - so innocent newbies will force them in and out, risking damage to the battery with possible disastrous, even fatal, results. I recall when I bought my SC. The only way I could get the battery out was by prising it with a knife. I had no idea of the danger! Let's hope HZ never have a death on their conscience for knowingly continuing to sell this highly dangerous combination of small battery box and too-large LiPo battery. |
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Post by flydiver on Apr 26, 2011 1:01:05 GMT 1
So, have you contacted them with your concern?
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Post by Dillzio on Apr 26, 2011 4:04:58 GMT 1
I just wrote them a email, here it is: Hi there, I'm a senior member of The Super Cub Club at proboards. As you've known for quite some time, the battery box for the Super Cub LP is too small for the provided LiPo pack. While we instruct all our new members on how to modify the battery box, there are obviously many fliers that expect everything to work as it is, and end up forcing the battery pack into the undersized battery box. This ultimately results in wire insulation breaking open, exposing the live wires within. While I have seen this happen myself when I was a beginner, I have never heard of this resulting in a serious accident, until now... supercubclub.proboards.com/index.cgi?action=display&board=batt&thread=3924&page=1You have been aware for some time now that the battery box (which was made to suit the old NiMH batteries) does not fit the supplied LiPo battery. You are now being made aware that this fault can result in a lipo fire, which, in a worst case scenario, could result in someone loosing their home, or their lives. Myself, and the many members of The Super Cub Club are all very anxious to know if hobbyzone plans to do anything about this issue? Many thanks, -Dylan (Dillzio on The Super Cub Club) |
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Post by not so newbie on Apr 26, 2011 5:12:53 GMT 1
nice job dill. lets see if it works. whats really dangerous is all these guys flying over and on water. drop a lipo in a glass of water and watch what happens. ecspecially if theres a small hole somewhere
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Post by Dillzio on Apr 26, 2011 6:53:05 GMT 1
I drop my Lipos into salt water whenever I'm about to dispose of them, all they do is bubble a bit (H2 of one electrode and O2 off another). Why, what have you seen happen when you drop a lipo in a glass of water?
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Post by Dillzio on Apr 26, 2011 18:27:19 GMT 1
Interesting reply from hobbyzone: ------------- Hello, Let me start by explaining that we are a retail hobby shop in Minnesota with a similar name that sells these planes and we are aware of the battery's being a tight fit, However, this is the first that I have heard of it causing a fire. I would suggest that you contact Horizon Hobby (the manufacturer/distributor) at 877-504-0233 concerning this as I am sure that they would be more than happy to take any input that you may have. Thank You, Dan Abbe ---------------------- my email was sent to info@hobbyzone.com, the email address I got from www.hobbyzone.com, but apparently they only have a similar name to hobbyzone and happen to sell their planes, which are actually made by horizon. Well that's about as clear as mud ...sent an email to horizon now |
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Post by renard80 on Apr 26, 2011 18:27:54 GMT 1
So, have you contacted them with your concern? Yep. Wrote by snail mail several months ago, hoping they would take more notice of a letter. Still waiting for a reply . . . . |
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