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Old Feb 15, 2013, 03:51 PM
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United States, SC, Irmo
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Look at this lipo, is it safe to use? bent and dented

I got this new lipo in the mail today and it must have got caught in a conveyor. It is slightly bent, creased in the middle and has a dent in the middle about the size of the tip of a finger. Battery voltage is normal for both cells, but I am afraid to charge it. I contacted the seller, not sure if it's worthwhile to send it back or even IF I should send it back in the mail, seeing that it's damaged. Waiting for seller's reply but I wondered what you guys thought of or if you had any experience with dented/bent batteries. I don't think the foil is pierced behind the shrinkwrap.
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Old Feb 15, 2013, 04:14 PM
Frankenstein recycled packs
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If that is NOT a 2S2P I would not use it. If it is a 2P (hard to tell by those pics) the crease may be at the junction of the two internal packs. Perhaps another pic of the whole battery is due?

Rick
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Old Feb 15, 2013, 04:29 PM
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http://www.rcgroups.com/forums/showthread.php?t=1831412
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Old Feb 15, 2013, 05:03 PM
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No, that's a dent in the corner. both cells run the whole length and you can see the shadow of them slightly in the pics.
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Old Feb 15, 2013, 05:18 PM
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I wouldn't take my chances with that big of a dent. I would discharge it to 0V and toss it.
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Old Feb 15, 2013, 05:40 PM
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Originally Posted by btown2 View Post
Oh, NO! That's my friend here on RCG, Spookeay, How terrible...

She did report, however, later in the thread that the fired dept said it most likely started at the electrical panel box as that was the hot spot and the fire had burned through the floor at that spot. So this was not likely a lipo fire. Point taken, however, it's not worth the risk.
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Old Feb 15, 2013, 05:44 PM
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Originally Posted by grimbeaver View Post
I wouldn't take my chances with that big of a dent. I would discharge it to 0V and toss it.
I get so confused with all the recommendations. You and many others say discharge to 0, some say cut and short the wires after that. But one of the things that makes a battery explode is overdischarge. So how do I discharge it safely?
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Old Feb 15, 2013, 05:57 PM
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Originally Posted by shahram72 View Post
I get so confused with all the recommendations. You and many others say discharge to 0, some say cut and short the wires after that. But one of the things that makes a battery explode is overdischarge. So how do I discharge it safely?
http://www.rcgroups.com/forums/showp...3&postcount=27

I'd leave it on the light bulb until the voltage was less than 1V/cell. If your battery charger has a discahrage function, use that. Does it?

I see you have an ECO4 which can be used to discharge the pack.
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Old Feb 15, 2013, 06:06 PM
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Yes, it does have a discharge function, but my question remains. How do I safely discharge the battery when taking it below 3v per cell makes it unstable, puff, and likely to explode?
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Old Feb 15, 2013, 06:19 PM
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It just simply stuns me how many people repeatedly post "is it safe to use this battery" time and time again and completely ignore all the other threads JUST LIKE IT and also conveniently ignore the "LiPo fires are REAL" thread that is stickyed at the top of this very fourm. People... listen to me very carefully... I know that the vast majority of modelers buy cheap batteries from Hobby King. The cheap batteries ARE NOT WORTH THE RISK TO YOUR HOME, FAMILY, PETS, FISH, LIFE, ETC. If you have ANY doubts about a LiPo, DISPOSE OF IT PROPERLY!! And please, for the love of sliced peanut butter, DO NOT start another thread about how to properly dispose of a LiPo!!

This was your "Please ignore the weekly battery safety rant from Mike Then".
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Old Feb 15, 2013, 06:35 PM
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Originally Posted by Mike_Then View Post
It just simply stuns me how many people repeatedly post "is it safe to use this battery" time and time again and completely ignore all the other threads JUST LIKE IT and also conveniently ignore the "LiPo fires are REAL" thread that is stickyed at the top of this very fourm. People... listen to me very carefully... I know that the vast majority of modelers buy cheap batteries from Hobby King. The cheap batteries ARE NOT WORTH THE RISK TO YOUR HOME, FAMILY, PETS, FISH, LIFE, ETC. If you have ANY doubts about a LiPo, DISPOSE OF IT PROPERLY!! And please, for the love of sliced peanut butter, DO NOT start another thread about how to properly dispose of a LiPo!!

This was your "Please ignore the weekly battery safety rant from Mike Then".
I appreciate your comments. I have read the other threads about battery disposal, but this was not the original purpose of my thread, and the answers in those threads are conflicting, that's why I ask again here.

I will not use this battery. Right now it's sitting on the concrete floor in my garage. I am putting it outside tonight. Hopefully the seller will send me a replacement, cause I do not feel right sending it back through the mail system. I think it's supposed to be mounted anyway in order to mail it back. But if something happened with it on the way back, I would feel guilty, and possibly criminally negligent. If they had opened it, they might have stopped it. I know if I found a battery like this at work (I work at UPS), I would turn it over to the Hazmat disposal guy as hazardous and would not let it travel any further through the system.

Is the battery fine, possibly. Voltage is fine, so it's probably ok, but it's not worth the risk. I'll just get another.
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Old Feb 15, 2013, 06:44 PM
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Lipos do just go off for no real reason. They simply go into a thermal run away long after anything was done to them.

So put them in a BIG fire proof pot & lid, or a garbage can with a loose lid. Have that container several feet away from everything else.

Best that you can do. They are dangerous & we know it.
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Old Feb 15, 2013, 07:30 PM
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Originally Posted by shahram72 View Post
Yes, it does have a discharge function, but my question remains. How do I safely discharge the battery when taking it below 3v per cell makes it unstable, puff, and likely to explode?
1 - Do nothing to the pack until you hear back from the vendor.
2 - A dented pack will degrade much more rapidly than an undented pack due to crystallization of the chemicals in the cell started by the dent.
3 - If and when you decide to discharge it, place the charger and pack outside and discharge it. It will swell up as it goes under 3V/cell but this is a different kind of swelling than that caused by overcharging which is the prelude to ignition. A discharged battery, that is one under 3V/cell, cannot explode/burn/catch fire/ignite/etc as there is no energy left in the battery.

Where did you read that overdischarging makes a battery likely to explode? Maybe on subsequent uses during a charge, but on discharging, never heard of one happening.
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Old Feb 15, 2013, 07:41 PM
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Originally Posted by hoppy View Post
Where did you read that overdischarging makes a battery likely to explode? Maybe on subsequent uses during a charge, but on discharging, never heard of one happening.
^ This. Overdischarging leads to internal damage and puffing but since the battery has very little if any energy left, there won't be an ignition unless you puncture it and light the gases. It's when the battery is recharged after an overdischarge when the problems happen.

mw
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Old Feb 15, 2013, 08:04 PM
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I think he is thinking it can explode by discharging it completely, no?
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