When I was unloading yesterday after I got home from the field, Idropped one of my lipo's on to the sidewalk. It didn't get punctured, but dented the side where leads come out a little bit. I placed the battery on a fire-safe surface and left it there for a good 4 hours. It didn't beginto bulge or smokeor anything. Do you thinkit's safe to charge andfly now or did Ijustmake $50mistake? I can post a pic later today if needed.

I wouldn't use it at all. If it's been dropped and you can see physical damage to the outside of the case the battery needs to be discarded and not used as recharging it could result in the battery bursting and catching fire.</p>

Ken</p>

I dropped a zippy once, and as far as I could tell it didn't hurt anything. It still works fine and I've never noticed any problems.

You should order some zippy flightmax batterys, and it could have only been a $20 mistake. Don't let the low price fool you, they have a great reputation in the RC community.

http://www.hobbycity.com/hobbycity/store/uh_index.asp

crap. that's what I was afraid of. oh well, live and learn, I guess.

Place it in a steel bucket in a VERY fire-safe area and charge it. Then discharge it (again, in a fire-safe area)

Do this two or three times. If it holds up, it'll be ok to use, just keep an eye on it.

I have one that was in a crash that has a slightly bent corner and it still works fine, but I don't give it regular use and I am extra careful with it.

Post a photo, let's see how bad this dent is.

ok, i'll post a photo when I get home.</p>

If you want to take one for the team, you could always burst it on purpose (safely of corse) and video it so we can have a neat lipo explosion vid on hand for the noobs who dont take it seriously

A simple steel bucket isn't enough, lipo burns pretty darn hot, place it in a ceramic pot or a charging bag made for lipo's, and when they do explode, stand way back. One guy at the field was charging his 2500 MAH 3s lipo and it was sitting on the top of the crossmember for the radiator( engine off for hours) and it went off. One cell of the 3 shot off like a roman candle, the other 2 went between the radiator and the engine and burned most of the wiring down there. That was a crappy day scrambling for water and a fire extinguisher.

here are the photos. it's a 3s 2200 mah lipo.

And people want us to power our own personal vehicles with these things!

Removed link after second thoughts. Sorry for the confusion..

Ken

Geez, let's fuel the LiPo paranoia!

I've seen more youtube videos of idiots intentionally overcharging (or shorting out) LiPos to blow them up, not sure what that's supposed to prove. If you plug a regular electrolytic cap into a wall socket, it blows up quite nicely too. So what? A static spark can ignite and explode gasoline, geez, and they want us to power our cars with that!! [X(]

Yes, you need to have a healthy respect for them, but the paranoia some like to propagate is a bit much. Most of the problems are due to idiots who overcharge them or over discharge them.

Getting back the the original question, it's hard to tell from the photos, but it looks like you bent the end of the cell packaging where the solder tabs come out. It doesn't look like the main part of the cell was damaged. If the cell is damaged, it will usually start to leak or puff up. I'd do what MinnFlyer suggested, charge and discharge it  a couple of times while you watch it, and see if it gets warm or puffs.

Think of a lipo electric vehicle and the lipo is punctured in a crash, that would incinerate you. That is my point, and gas needs more than just a spark. It needs to atomize and have a good mixture with air. You can't just ignite liquid gasoline.

should be fine. just be careful with it,</p>

 do what minn said. </p>

I have crashed my electric mini flyers almost 1000 times with my 3cell 700mah lipos and they just keep on going.... I am just waiting for the fire to start someday.... You guys really take it overboard, please send all your dropped lipos to me I can really use them..... If they were so sensitive they would blow up on planes and during shipping when boxes get kicked around.... its not nitroglycerine we aretalking about....  Lipos only blow when overcharged, if they are punctured they usually take awhile to fire up !!

Uh... no

After being damaged, it takes a while for the chemicals to react in a LiPo pack, whereas gasoline WILL ignite imediately with only a simple spark. It is true that liquid gasoline does not burn, but have you ever seen liquid gasoline that wasn't surrounded by gasoline vapors?

Just ask the owner of any Ford Pinto, who was rear-ended back in the 70's, if they wish they had been driving a battery-operated car instead. On second thought, don't bother asking them, they're dead.

Here's a news article from just 2 days ago:

<span style="font-size: medium;"><span style="font-family: Times New Roman;">A Clear Lake man was severely burned Saturday after the Ford Pinto he was driving was rear-ended and burst into flames. The Stearns County Sheriff's Department says it happened on County Road 51 in St. Joseph Township at 6:39 p.m. Saturday. 18-year-old Jeffrey Hinkemeyer of Clear Lake was driving his 1979 Pinto westbound and was slowing down to make a left turn when it was rear-ended by another car. The Pinto started on fire on impact, and Hinkemeyer was severely burned. He was airlifted to the Hennepin County Burn Unit for treatment, and his current condition is unknown. The people in the car that hit the pinto were taken to the St. Cloud Hospital but refused treatment. The crash is still under investigation. There were many lawsuits anda massive recall of Ford Pintos in the 70s and early 80s because of similar injuries caused by fires after rear-end collisions. </span></span>

Actually the lipo in that video burned up instantaneously. Yes, gasoline that escapes its container will ignite easily because it allows for the conditions to become right. Still feel safer with a long proven technology where only a few turd cars caused problems. Heck even the 60's mustangs had a problem with gasoline being sprayed into the passenger compartment upon a major rear collision. Pinto owners probably would have rather been driving a car with a real amount of steel around them. New mpg standards are gonna be putting us all back in a pinto.

Yeah, an abused &amp; swollen LiPo will explode when beaten with a large stick! Wow, I never would have guessed that!

The safety of Lithium batteries in vehicles is a real issue that is being addressed by auto makers. That's the main reason none of the major auto makers has come out with a vehicle using that technology yet.

You can fear LiPo's if you wish, and stick to NiCd and NiMH battery technology, just don't expect to have an electric aircraft that will fly worth a damn. Let us know how your Phase 3 EF-16 flies with a NiMH pack!

I never said I wouldn't use them, only that riding on top of one is a scary thought. I actually have 5 lipos now and have never charged them in a sack or can and have actually left them charging in the garage on the workbench without supervision.[X(] I'm sure the f-16 would fly like garbage with anything else, and thanks for checking out my profile.