rgreen24

My Feedback: (6)

Hey guys,

I wanted to let you know about an incident I had over the weekend that caused some high concern. I flew four flights yesterday, then returned home. I thought I would go back out later and fly three more, so I charged three more batteries. The three batteries I was planning on using, were flown the previous day, and were not overly discharged. I took my kids to the movies as my wife did not want to go, and that turned out to be the best thing for the family. One of my 2014 packs decided that it no longer wanted to live and decided to catch fire all by itself. I have always thought that the best time for these to catch fire, would be during the charge cycle. This incident happened almost an hour after charging the pack. Keep in mind that after I charged the pack, there were immediately put into my flight box for storage until I got back from the movies. After I took them off the charger, the batteries did not see warm in any way, cool to the touch. I have had these batteries for two years and as far as I can remember - they where not damaged in any way. Due to my wifes' heroic action, the house did not catch on fire like my toolbox did. She brought them out to the drive way and put more water on them to kill the flames. I have been pretty cavalier with packs, leaving them out once they are charged and not putting them in something safe for storage....those days are done. If this can happen to a battery sitting with a stored charge, I will not longer leave my house or family unprotected.

I bought a safe yesterday, but apparently that may not be the best thing for them either as the battery give off a gas and they need to breathe. In other words if you left them in a safe you may be creating a bomb scenario. What I did was - several years ago, I bought a metal ammo case. I removed 3/4 of the rubber around the case allowing for the exchange of air to occur.

If any one has any other creative ideas on how they store there lipos, please contribute to this thread as I think it is important as a community that we spread the message that this technology which has been proven to be safe for the most part also can be dangerous.

thanks,


Robert

ltc

My Feedback: (3)

Store, charge and transport LiPos in a LipoSack. They come in various sizes for different size (energy density) packs.
http://liposack.com/
(FWIW, I only use the genuine Liposack; I've seen some cheaper copies and wouldn't use them except for perhaps 2s Rx batteries)

Do NOT store, charge or transport them in a sealed enclosure.
Do NOT store, charge or transport all of them together in the same container; individual LiPo sacks are best to help prevent one battery from igniting another battery.

Stuart Chale

Glad it didn't cause any major damage. I suspect a case full of our Lipos could cause some real damage.
I can add another place not to store your batteries. In your pocket

Not exactly the same but I work in an ER and yesterday had a patient come in due to burns on his leg from a lithium ion battery. An extra battery for his "vape device". Must have shorted on something metal in his pocket and caught fire. Second degree burns to his thigh and behind his knee. Earned him a burn unit admission

MAVROS

I also had a lipo catch on fire in my tool box.
Luckily I was able to disconnect and throw it away.It was less than 50 cycles old .

One of the reasons I will not convert to electric power.

mwoytassek

Robert


My method:

Store the battery's in a plastic box. The battery's are kept on the long side not on the end. This is to reduce the damage. If stored and transport on the end there is a Higher risk of damage to the cell connections.


Battery's are charged on a small table next to the sliding glass door out side those doors there is a concrete patio. If the is a problem the door is opened and the table is pushed out side.


Also I have a charge station the setts on a big welding blanket so the system and battery can be covered and moved out side.
Each charing station as a battery power smoke /fire detector. A 8 lb CLASS ABC dry fire extinguisher is in the area. This will not put out the battery fire but is used to put out the surrounding fire,




For new or unattended battery charging I have an old gas grill the sits in the concrete patio the charging system and battery can be placed inside.


In my battery class at work the first day , Batteries are bombs and we are trying to control the discharge over a long period of time.




Mark

Jason Arnold

This is my new LiPo storage method and I've also tidied up my charge leads. What do you guys think?



Just kidding. Seriously though, storage and wiring like in the picture is a recipe for fire. Many people don't give LiPo's the respect they deserve.

Cheers,
Jason.

nonstoprc

My Feedback: (90)

It will be good to check the charger to rule out overcharging, which is one of the root causes of lipo fire.

rgreen24

My Feedback: (6)

Did that today, and it charged my F3A packs just fine, no fire. The more. Think about it, I am sure there was a short somewhere in the battery, it's just too bad I will never be able to find out where the short came from

ltc

My Feedback: (3)

Assuming the packs were not dropped or damaged mechanically, shorts often occur at the cell tabs/terminations
It is generally a good idea to strain relief the balance wires (attach them to the dischsrge leads with tie wraps for example)
Also do not hang or remove the packs by the dischsrge leads (see people do it all the time)
It also helps to never charge past 4.1V and avoid discharges below 3.6 if possible

After that it comes down to internal manufacturing defects and luck !

AmericanSpectre505

Hey Robert,

I use a green ammo can; 5.56 1000 round can. I put cat litter in the bottom and set the pack(s) in the can upright. I drill about six 1/4 inch breather holes in the top of the lid. I have done this for years now, years ago I had a spare RX 950Mah pack catch fire in my 14MZ case. I caught that, as I smelled the foam smoldering on my way to the field. That is when I decided to utilize my ammo cans.

You can find the ammo cans in most pawn shops or online. That's what I do. I get the cans when I order ammo anyway.

Glad it didn't do any damage.

Bill

rgreen24

My Feedback: (6)

I just bought 2 additional ammo cans to grow with the 2 I purchased previously. I removed 3/4 of the rubber around the can to relieve the pressure in case something happens again.

The Saylors

The lipos are a tricky thing. A ton of the videos that you see of them exploding and or catching fire due to damage and they always seem to need to sit for an hour or two (I'm assuming to become wildly unbalanced) before they go up. I get kinda irritated when people ask if a lipo bag i needed, is your house needed? lol it's just not worth the risk for a $20 lipo bag or a surplus ammo can, to me anyway. These things need respect but if you give it some then you will have a pleasant day. My $.02

rgreen24

My Feedback: (6)

I have always respected the technology, and have been flying electrics since 07 without incidence. I may have been cavalier in the way is stored them, but it was my thought that if a lipo was going to catch fire, it would do so during the charging cycle. With my lipo fire that happened 2 hours later, is something you cannot plan for. However as I remember, I marked these batteries as practice batteries as I did not think they held their voltage well right off the bat. However I flew them the day before and they did awesome, so there was not really any warning sign. However from now on, if I suspect any battery of having an issue, it will be discarded immediately. I may also think about buying and replacing my batteries every year as another precaution.

The Saylors

Usually charging is the culprit for an intact battery, but if it has been damaged (and this is rarely obvious from the outside of the pack) it usually just needs a little time before it splodes. Inside the pack the cells can become an accordion due to impacts/hard landings or the tabs will split or crack. From what i have seen its best to just put them in an area that you are comfortable having a fire and hopefully be pleasantly surprised rather than running the loosing property or even (heaven forbid) life. I charge mine in the oven in all honesty lol. I figure that is a pretty safe place. Oh one thing is that if you ever spot a performance change from what you are used to (increased/decreased power/run times) then i would be on guard, i don't know the science behind it well enough to spout facts but that seems to be one of the only warning signs that they give aside from puffing that something is wrong. I noticed you said that the batteries did well just before the incident were they usually didn't before. It seems counter intuitive for extra power or run time to be a problem but it seems to mean that architecture of the battery's interior has changed is some way which is never good. As TLC said it can sometime be down to the factory and luck as well!

rgreen24

My Feedback: (6)

Completely agree with you. The thing is I have never really liked the battery that caught fire. But I kept it anyway as I could use it for practice. I am sure many of us have batteries just like this that we use for practice. If I could offer some advice, if you are using it for practice only because you suspect something is not quite right, whether it's not holding the charge it once did, takes longer to charge or doesn't have the power it once did. Then it may be time to recycle them. My .02 cents

f3a05

I think you can get some clue that a battery is nearing the end of its safe life, by monitoring the IR of each cell,
Although the IR numbers will vary a bit from day to day,mainly due to the ambient temperature, you can spot the trend.
In my experience, the IRs will stay pretty much the same across the ten cells in a typical F3A pack,just gradually increasing a bit over number of recharges,but eventually, one,or two, cells will show a fairly rapid increase above the average IR----and this will often coincide with other indicators like slight puffing,longer recharge time,&c.
Personally, with my Zippy Compacts, the IRs start around the 1 to 2 mOhm mark, gradually rising to 3 or 4 over time---and when one or two fairly suddenly go to 6 or 7,I discharge the pack safely through a series resistor (7 lorry sidelamp bulbs) and recycle them.

nonstoprc

My Feedback: (90)

Flying time is also a good indicator of whether a pack is near its service life. For example, if the ESC gives a soft slow-down during a flight for no other reasons, it usually means the voltage is dropped too low, and this rarely happens to a good pack.

philakapd

I have two storage methods, depending on my location.

At home:
I keep my LiPo's stored inside an old crock pot. I place a 40lb bag of play sand (contained in a plastic bag) from the home improvement store on top of the crock pot. DO NOT PUT THE GLASS CROCK POT LID ON! If a fire occurs within the crock pot, the sand bag will melt and the sand will pour into the crock pot. All this time, the LiPo is also stored within a welding blanket. The crock pot is placed on a concrete floor in my garage, away from combustibles. I have a smoke detector placed directly above. I keep several fire extinguishers in close proximity as well.

Out flying:
LiPo's are stored within welding blanket and placed inside a fire proof safe. The safe is NOT locked and gases can escape should a fire occur. I keep a fire extinguisher in my vehicle (Velcro to the carpeted floor). I do not charge batteries in my vehicle or leave batteries unattended. Once I arrive to a flying site, the first item of business is to get the batteries out of the vehicle and placed in a shady spot outdoors.

I love LiPo batteries. I love gasoline, too. Both have their place in the hobby and must be treated with respect, equally. I have a very simple approach to LiPo safety; I imagine a battery pack is a can of gasoline (it can have the same potential energy to destroy).

Would I store it in the house? NO.

Would I keep it in a vehicle? NO.

Would I let my children play with it? NO.

Do I trust it? NO, I handle it with respect, watch carefully and store accordingly.

Good luck and store safely.

Don't forget to have fun!!

Clear skies to all.

-PD

rgburrill

Where are all the admonitions about not leaving charging LIPOs unattended? I realize standing over them while they charge is not realistic but leaving home while charging? That's foolish.

The Saylors

I agree. I have also been concerned when transporting them that they will be in the trunk and explode before i can get them out. I put them right next to me on the passenger seat now so that i can keep and eye on them and huck them out the window if somethings starts to happen. They used to really stress me out but i have seen enough of them go up to know that i will at least have a few minutes of warning before things get really dangerous, so on the free way they go should they decide to pop.

Brenner

It's good that everyone posting in this thread is super cautious, but the real problem is all the other pilots who have been using Lipos for years, and think that they have a handle on all the safety issues.

I am/was one of these.

Until I talked with Robert about his incident, I thought that I could always predict when a pack was going bad, and that the worst it would do is puff and split.

Also, I assumed that once a pack is charged, or discharged, any risk of fire was over so I stored them in my car and my house without a second thought.

Now I realize that I was just an accident waiting to happen, and I'm sure that there a lot of others out there like me.

Brenner ...

nonstoprc

My Feedback: (90)

Sounds like storing our packs into lipo safety bags should be a reasonably good solution.

Check this test video out. https://www.youtube.com/watch?v=2oNQdSUJi68. Pretty hilarious :-).

The Saylors

That kinda what is use is a "bag" style safe. More like ten bags that have been sandwiched together and coated in glue, thing is one layer away from being a solid safe. I do like it though, gives me a little piece of mind.

n233w

I'm with Brenner, and I like the fuel analogy, which leads me to conclude, No Lipo Storage or Charging in the House or Garage.

I store my batts in vented ammo boxes, but even the smoke/fumes from a runaway 5 cell 5000 mAh lipo would ruin all the stuff we store in the garage.

I didn't see the specs on the batts in the video, below, but I don't trust such a solution for our bigger batteries. Better safe than sorry. Waterproof storage box outside here I come. Billx

nonstoprc

My Feedback: (90)

n233w,

I agree that storing the lipo packs off the house or garage is the good idea. But during summer months in Southern states, the outside temperature could can reach from 90 to 100, which may not be good to lipo packs.

Saylors,

Yes, the storage bags are just an extra piece of mind. Personally, I would store them in these bags, and then in file cabinet, or ammo boxes.