My Wake Up Call for Charging Lipos

[r/c basher]

I think this is my wake up call for charging lipos. www.rcgroups.com/forums/showthread.php?t=1201043 The next time I go to my lhs Im buying 2 or 3 lipo safe bags. I dont have any yet.

[Gabe]

Holy Crap! I'm so sorry for your loss - especially your pets. That's so terrible. I'm ordering three lipo safe bags right now. I have a wife and two dogs that I love dearly.

Man, I had no idea.

[r/c basher]

Feb 28, 2010 13:14:03 GMT -6 Gabe said:

Holy Crap! I'm so sorry for your loss - especially your pets. That's so terrible. I'm ordering three lipo safe bags right now. I have a wife and two dogs that I love dearly.

Man, I had no idea.

That wasnt me, it was someone else. I just dont want the same thing happen to me as this guy. Ive known the danger of lipos but never have tooken extra safety precautions like putting them in a fireproof box.

[BTCat]

I'm glad you posted this, Basher. Just a sober reminder for me to be more careful. I hate it for that guy.

Someone (Doozer or 19k, I think) said something about charging in a clay pot. I charge on a concrete floor with the clay pot over the top. Hopefully, if the day comes, the pot will help smoother off the oxygen and it and the concrete will contain it. Only worry I have is that such a fire will follow the wiring to the charger and spread from there. I saw a guy short out a 24 volt wire on a crane one time. Before he could get the cables cut the fire has spread through 20 feet of frame (probably about 1 minute)

[r/c basher]

I posted it to remind myself just how dangerous lipos can be. I feel bad for the guy. I charge my lipos in a clay pot too but the pots diameter is only 4 or 5 inches and Im sure if a lipo caught fire it would blow the top right off. I did find a little metal toolbox in my closet that I think will work better until I can get a lipo safe bag.

[19000rpm]

Charging in a safe manner is a must. I use a fireproof container and always monitor the charge with a timer.

I think it was ernie who said he charged his in a clay pot inside his fireplace. If you're going to have a fire in your house that's the only place to have it.

As usual, this lipo fire seems to have been caused by human error. Wrong charge rate AND number of cells of the battery. If he'd used a balance connector that would have never happened. The charger alarm would have gone off instead of his fire alarm and his house wouldn't have ended up in smoke.

So what's the lesson? We're human and we make mistakes. We need to protect ourselves from our fallibilities. With dangerous things I assume I'm likely to do something stupid and take steps to protect myself from myself.

[dubehigh]

yea that sucks, my house caught fire two years ago. not from a lipo. but its a pain in the a$$ with insurence companys. it took a year.

as for charging lipos, i have an old fridge out back i use as a smoker. thats were i charge my lipos. two months ago i had one go up in smoke, caught it just in time.

[BTCat]

These things are starting to scare me more and more. I think I will build a small fireproof container better than what I have. Mine would contain the blaze and might even be tight enough to smoother it, but I don't want to take any chances.

[McKrackin]

In the early stage of my lipo experiences,I took extraordinary measures for safety.I charged my lipos in the fireplace.That's true.

After hundreds,if not thousands,of charging cycles,I have absolutely no concerns with my lipos.I have a charger on my wooden desk.Another in the corner of my living room on a marble mantle.Another in the garage.
I have absolutely no reason to give them a second thought.

I keep my lipos in excellent condition and simply throw them away at the first sign of even having a soft feel to them.

100% of lipo fires are human error.No exception.
They burn from charging them wrong.Too fast.Too long.etc.
They burn because of overlooked damage.
If a lipo is in a crash,it should be supervised during charge for at least a dozen cycles.

If your charger is good and your lipos are good,there is no reason to worry or put them in a bag or anything else.
If it helps you sleep,that's all good.But,they are nothing to lose sleep over.

There are dozens,maybe hundreds,of other things in your home that are far more dangerous and lipo fire threads and horror stories are detrimental to the sport.

I'm sure that many many people that preach the dangers of lipo fires have at least one loaded gun in their home or gasoline in a plastic can in the garage.

Maybe 5 homes were destroyed last year by lipo fires.
How many weren't?How many tens of thousands of lipos are on charge right this moment?How many will burn tonight?
More than likely....none.

[19000rpm]

In some ways Lipos could be compared to a gun. If you understand how to use the gun and if you handle the gun safely nobody's going to get hurt.

What we don't want to do is have some guys paranoid about lipos. Please understand this; it's people not understanding the lipo and then misusing it that results in lipo fires. To paraphrase the old add-age: "Lipos don't kill people, people kill people."

Some facts: Lipos will not spontaneously combust. Lipos will not catch fire during charging if the charge rate is properly set at, or below, the recommended level and the lipo is not damaged.

FACT: Unsafe handling can be attributed to 99% of lipo fires.

So, what's unsafe handling? Hit the lipo with a hammer. Puncture the lipo. Intentionally, or unintentionaly, overcharge the lipo or over discharge the lipo ("Over flying" your lipo, while it may not actually cause a fire, it can ruin the battery). Throw a lipo in a fire. Use or charge a lipo with a bad cell (Check each cell after each charge. A good charger will do that for you.) Use or charge a lipo that has been damaged unless you have determined the damage has not affected the lipos safety.

Some safety steps: Use a good charger with a timer, alarms and both a power lead and balance lead connectors. Double check your settings before starting the charge. Monitor the charging (Don't leave it someplace and then forget about it). Store your lipos in a cool place rather than a hot place.

I recommend using a lipo safe container for charging lipos for the same reason I would use a trigger lock on a gun. People make mistakes! But, it's really hard to discharge a gun unintentionally when the locks on and a lipo will not burn up your house, garage or car if it's charged in a fireproof container.

[rcdbutz]

Never had any problems myself. I'm pretty good about looking at the battery and setting it to 1C, even if the charge capacity is higher, I'm willing to wait. I'll also usually be in the same room as my batteries as they are charging. Of course, it's easy to make a mistake, and it only takes one time. Sometimes I leave the little single cell 3.7 Volt batteries for the ultra micros (mCX, mSR, Ember, Vapor, Sukhoi, and 4-site) charging for longer than I should. I'll just throw 4 of them on the charger and go about my business, and sometimes forget. Those ones are pretty small and harmless though.

I think I'll be ordering some lipo bags soon. Even if I probably don't need it, if I add another step to the charging process, then I'll be more cognizant of the safety procedures over all.

[BTCat]

19k and Ern, you both make some very valid and well written points. I don't fear lipos, but I don't completely trust my charger to always be correct or myself to always remember. I think what 19k wrote is right. Trust but keep safe. I have been charging on a concrete floor with no combustibles around. I've been thinking about finding a better way to charge correctly and still feel any incident would be contained. I have an old Korean war eraAmmo box. I think I'll line that and rig the wires through. It latches tightly and is air tight. It is easy to used and I could mount my charger to the side of it. I think I could make a nice portable package out of it.

Human error, no doubt, is the primary cause. But frankly I don't trust myself to pay close enough attention sometimes.

[akent]

Mckrackin and 19k are right.
I agree 100%.

I have accumulated a lot of puffed batteries now. They also lose capacity when they puff.
So, in my inventory of batteries from HC, they seem to last about a year. The number of charges and discharges are in the hundreds only, before they puff.

I do have a couple that I suspect of puffing quickly. I cannot prove that as I retired several batteries at the same time. Ugh.

The above listed puffed batteries were all kept fully charged at all times, so I could fly at a moment's notice! I know roughly how long those times were, and the batteries lasted a year.

Now, I'm making sure the batteries are kept at a 'storage' voltage. We'll see how these Chinese batteries handle that.
Kent

[19000rpm]

Mar 2, 2010 18:08:40 GMT -6 BTCat said:

19k and Ern, you both make some very valid and well written points. I don't fear lipos, but I don't completely trust my charger to always be correct or myself to always remember. I think what 19k wrote is right. Trust but keep safe. I have been charging on a concrete floor with no combustibles around. I've been thinking about finding a better way to charge correctly and still feel any incident would be contained. I have an old Korean war error Ammo box. I think I'll line that and rig the wires through. It latches tightly and is air tight. It is easy to used and I could mount my charger to the side of it. I think I could make a nice portable package out of it.

Human error, no doubt, is the primary cause. But frankly I don't trust myself to pay close enough attention sometimes.

A lot of guys use ammo cases to both charge and store their lipos. That's about as safe as you can get.

That's a neat idea to have the charger actually mounted to the ammo case.

[McKrackin]

¡öAlways use a charger made to charge LiPo packs.

¡öDouble check that the settings for the lithium polymer charger are correct for the pack being charged ¨C this includes the cell count as well as the current settings.

¡öIn general, most lithium polymer batteries should be charged to no more than 4.2 volts per cell or depleted to less than 3.0 volts per cell. There are new generation batteries available that can handle higher / lower voltages, but they are still new and thus are the exception to the rule.

¡öEnsure that charging leads are connected correctly. Reverse charging can lead to cell damage or a fire or explosion.

¡öAlways charge LiPo batteries on surfaces that won¡¯t catch on fire such as cement, steel, ceramic or stone. Wooden tables and carpeted floors are not recommended charging surfaces.

¡öDo not charge batteries near flammable products or liquids.

¡öNEVER CHARGE A LIPO BATTERY WHILE INSIDE YOUR MODEL or other electronic device. If it catches fire it can lead to total destruction of the item it is being charged in.

¡öLiPo batteries should be charged within a temperature range of 0C to 50C. Batteries charged outside this temperature range may experience leakage, heat generation or cell damage.

¡öNever leave a charging lithium polymer battery pack UNATTENDED.

¡öDo not charge inside an automobile, especially while driving.

¡öDo not store batteries inside an automobile.

¡öNever charge a LiPo pack that has ballooned or swelled due to over / under charging or from a crash.

¡öNever charge a lithium polymer battery pack that has been punctured or damaged in a crash.

¡öNever, under ANY circumstances let the positive and negative battery leads touch. It can lead to cell ballooning, cell damage or fire or an explosion.

¡öHave a fire extinguisher near the charging area or a large bucket of dry sand. Do not try to distinguish with water.

¡öIf you notice your LiPo battery pack is swelling, stop the charging process immediately, put the battery in a safe container and observe it for 15 minutes