LiPo ... why the hate?!

[LI-ghtcycle]

I'm gonna ruffle some feathers here, but I just gotta say it, why the fear of LiPo!? :lol:

It's in every cell phone, every lap top, and a number of other every-day items we all have in our houses.

When was the last time you heard of a phone or lap top causing a fire?

And yes, if you abuse them, the bite.

How is charging LiPo really any more dangerous than having a gas can in your living room?

Of course, common sense and some precautions, but seriously, you walk into any RC hobby store, and 9 out of 10 places are going to cell you a LiPo battery to go with your plane, car or boat ... yes even to .... *GASP* newbies!!! :lol: :lol: :lol:

I have to admit I had this prejudice too early on, and have paid for it in the form of 100's or hours building battery mounts for Dewalt A123 tool battery packs, and I have had way more trouble with those than I ever have had with my LiPo.

I have never had a LiPo pack puff up or even get warm either in charging or discharge.

I have however, accidentally shorted a 12S group and the worst that happens is I caused some 5MM bullet plugs to melt a bit, and once I had a short because just had to try and save $4 and make my own home-brew socket connector, and the pin inside the ring of the connector touched, I saw a tiny smoke cloud, heard a "pop!" and noticed that the pin had vaporized.

Other than my own small mistakes, I have had little to no trouble with LiPo at all! :wink:

 

[Ricky_nz]

Yeah there does seem to be a massive overreaction by some at times...
A lot of lessons have be learnt since the early lipo.

There are a few people that shouldn't have lipo just like there are a few people who can't be trusted to handle petrol safely as per this link

Fire Service shift manager Scott Osmond says a man had been quite legitimately siphoning petrol out of a car.

"Due to the fact it was dark, he decided to light a match or a cigarette lighter to help him see better, and unfortunately the results of petrol in the flame caused a fire," he says.
http://www.nzherald.co.nz/fires/news/article.cfm?c_id=202&objectid=10758967

 

[Demosthenes]

Well 500+ Whr's of lipo is way more potential energy than a couple watt hour cell phone batteries. There is more energy in a laptop battery, but still nowhere near ebike amounts. Just saying.

Myself, I don't have a garage or anywhere to charge that's not carpeted or surrounded with flammable stuff. So I choose not to.

 

[amberwolf]

I think the only real difference between the majority of consumer-type items powered by LiPo and the stuff people here are using is quality control.

QC on the typical cheap RC LiPo packs is apparently pretty bad, based on the percentage of packs people here report getting that are either already dead, even puffed, or that die very shortly afterward (sometimes spectacularly) despite being treated normally.

QC on the typical consumer-type devices' batteries is pretty good, given that there are failures, but not that many, and few are catastrophic.

Statistically, it'd be unlikely that of all the failures that happen to RC LiPo packs, that most of them happen just to people that post them on ES, so I would have to take what is reported as fairly representative of them.

I'm also pretty sure that there are lots of failures of consumer devices that don't get reported anywhere, just tossed in the bin because they're so cheap. Still, percentage-wise, it's probably at least a couple of orders of magnitude less of a problem with these than with cheap RC LiPo.

I'm also sure that there is "good" RC Lipo that has actually been thoroughly quality checked rather than just manufactured, bundled into packs, stored a bit and then sold and shipped, but I'm also equally sure that the cheap stuff usually used here on ES is *not* in that category.


Sure, there will always be manufacturing defects, but proper QC would weed those out from the stuff that actually gets sold, and those cells would then be destroyed and recycled (rather than just resold by someone else, or even the same place under a different label of some type, perhaps).

 

[LI-ghtcycle]

I agree, there is a problem with low quality LiPo, and we still hear about puffed packs, a fire or two, but I believe this us due to operator error 90% of the time, packs don't puff unless you push them too far, and if you take the chance, charging them is really dangerous.

Storing them below 90% charge is also a big risk IMHO, as you need a safety margin above 80% and that can happen just letting them sit too long and cause "spontaneous" combustion.

A good quality LiPo is a lot like a good quality charger, expensive, reliable, yet it would seem there is a tendency towards buying cheap and expecting LiPo to fail no matter what, and to run them hard, but that is the cause of the problem as much as the poor quality of the cheap packs & chargers themselves.

I'm pretty meticulous with mine, and I take more time than I need to make sure they are balanced with-in 0.05 V and usually my packs stay with-in 0.007 V once they are fully charged and then balanced.

I'm working towards using two 10S Turnigy Nanotech bricks or four 5S bricks with 2s, 2p as a standard battery size requiring nothing more than a set of wires in the harness for each positive and negative lead, and eventually a set of Methods' LVC/HVC boards, and then a good quality charger that is bought at a local RC hobby store for a friend who is completely new to the hobby, and it's looking like this will save him close to $200 VS a plug in the wall battery with BMS considering there is really only one LiPo with BMS battery off the shelf (that I know of) at this time, and I'm really liking the idea of the minimalist boards of Methods' instead of a traditional BMS, taking all the equipment that is normally attached to the battery that actively balances the batteries, and leaving that with the charger so it's not subjected to the rigors of being on the road with the bike.

A typical safety precaution that is recommended at my local hobby shop is to use a pyrex or ceramic cake pan or old metal desk drawer as a tray to hold the batteries in that are being charged (I use LiPo fire retardant bags inside an old metal refrigerator hydrater tray) that can be picked up and taken outside at a moments notice if there is a problem, but personally, since none of mine have never even gotten hot while being charged or used, I generally have mine in the garage while charging while I work on things, or I just check on them periodically (once every 15 - 30 minutes) and this has worked well for me.

If you don't have a garage, you can always have them in the a fore mentioned tray in the kitchen or bathroom tub, and if there is a problem take them outside to vent, but I truly believe if you stick to the higher quality stuff, keep things with-in a healthy safety margin (never charge over 4.15V, never discharge below 3.0V) that will give you the ability to keep them from over-charging and discharging.

I have only used the Turnigy Nanotechs (about a year now) and I have never seen them sag more than 1V even with 50 - 90A draw, never seen them warm, never seen them puff up, and they still have their capacity, and I use the entry level 25 - 50C version, not even the high-end Nanotech stuff.

There are other high quality LiPos that others have had similar experiences with, but anytime I have seen a post about a fire, puffed packs, or other problems with LiPo, it has been the low end 15 - 20C LiPo that sags considerably, is usually run really hard, and bulk charged.

I plan on parallel charging my own soon, but for now, it's just as easy to do 12S or 8S at a time.

 

[TylerDurden]

When was the last time you heard of a phone or lap top causing a fire?

"Apple agreed to a recall of its first-generation nano in South Korea, and expanded that to include Japan in August 2010. The issue actually dates back to 2008, when Japan's Trade Ministry announced that the devices had caused three fires and minor burns. In July 2009. "
http://www.pcmag.com/article2/0,2817,2396309,00.asp

How is charging LiPo really any more dangerous than having a gas can in your living room?

Gas cannot spontaneously ignite...
"The pack was just sitting there undisturbed, and not connected to anything." http://endless-sphere.com/forums/viewtopic.php?f=14&t=27494

 

[dogman dan]

Could it be people don't want to burn down thier house? It is a bit of a problem to safely store large lipo packs.

Any chemistry, including lead can short good enough to start a flamable material nearby on fire. But lipo is just a bit more likely to do bad things if overcharged than others.

Noobs, who have zero electrionics knowledge are very likely to screw up building a 48v pack out of several packs of lipo. This is not "buy one pack and pop it in a RC car"

 

[LI-ghtcycle]

Could it be people don't want to burn down thier house? It is a bit of a problem to safely store large lipo packs.

Any chemistry, including lead can short good enough to start a flamable material nearby on fire. But lipo is just a bit more likely to do bad things if overcharged than others.

Noobs, who have zero electrionics knowledge are very likely to screw up building a 48v pack out of several packs of lipo. This is not "buy one pack and pop it in a RC car"

Will a fire from single abused & unattended LiPo pack cause any less damage in a fire than a 5 Kwh pack? :wink:

Agreed, any chemistry can cause problems, but why is there such a knee-jerk reaction to the danger of LiPo that we assume someone is new and going to have a problem as with a recent thread about building a go-kart for a kid using LiPo?

In that case he wasn't a newbie at all, however, I contend a good charger, good safety and a responsible user will stop 99% of all troubles caused by misuse and abuse of LiPo packs.

 

[LI-ghtcycle]

When was the last time you heard of a phone or lap top causing a fire?

"Apple agreed to a recall of its first-generation nano in South Korea, and expanded that to include Japan in August 2010. The issue actually dates back to 2008, when Japan's Trade Ministry announced that the devices had caused three fires and minor burns. In July 2009. "
http://www.pcmag.com/article2/0,2817,2396309,00.asp

How is charging LiPo really any more dangerous than having a gas can in your living room?

Gas cannot spontaneously ignite...
"The pack was just sitting there undisturbed, and not connected to anything." http://endless-sphere.com/forums/viewtopic.php?f=14&t=27494

Will LiPo spontaneously ignite if charged properly, maintained and not abused?

I will contend you have a much greater risk of being hit by a car than having a LiPo fire, and yes, if you go cheap, and cheaper is better, bulk charge, and don't balance your packs very often, you can have even "safe" SLA's die.

I just talked with my friend who converts and sells electric cars for a living and he has two kinds of customers when it comes to batteries, ones who charge & maintain them, and those who ruin them on a regular basis due to letting them sit with out charging them regularly, not checking them and bringing up a low SLA battery (most people can't afford more than SLA's still for their cars, even SLA for a 20 - 30 mile range car costs about $5,000 for a decent sized pack for the typical converted or purpose built cars) so that it doesn't cause problems for the entire series group. :wink:

Sure LiPo has the potential to cause a fire, and if you don't respect it, so can a gas can.

I contend that if you are using good quality stuff and storing it properly (storing in a fire resistant container or in a metal box on your bike if you must away from combustibles) just like storing a car or motorcycle, even though there is less of a chance of a fire, I wouldn't store my motorcycle in my kitchen (ok I know that is common for some Harley owners, but each to their own. )

I'm just saying, how many houses have burned down because of even a defective apple LiPo or other device? I bet more kids playing with matches have burned down houses than even defective/abused LiPo.

I don't trust the industry standards with charging up to 4.2V and discharging to 2.7V per cell. This is pretty obviously done IMHO to ensure a short life span of the average LiPo battery (with exception of small portable devices like phones with purpose built batteries with small capacity that seem to do fine) used in the RC world.

I understand having as much power density in a pack as possible for a RC plane for instance, but if more people knew the truth about keeping the charge voltage down, and not discharging them so far, I bet those running LiFeP04 in their RC planes would rather use LiPo if the knew they could have virtually the same amount of charging cycles.

By limiting charging to much lower than the dangerous level of charge of 4.3V per cell, I believe we are not going to have the same problems the average LiPo pack of yesteryear that was over-charged, over discharged by design, and I bet that cheap faulty chargers & power supplies (cheap quality not price only) are more the culprit than the cells themselves.

My first LiPo charger was ruined by a $89 PS I bought locally from the hobby shop, and it ruined the first Hyperion charger I bought before I realized what was the culprit.

If you're going to store LiPo under 80% charge, you're asking for trouble, if you don't balance charge often enough, you're asking for trouble, if you store them where you can't safely let something burn, you're asking for trouble, just like a gas can, but that is the fault of the user more than the chemistry IMHO.

I'm not saying it has never happened, but I would love to see problems associated with high quality LiPo that has been well taken care of, not necessarily Turnigy Nano Techs only, I know there are other high end packs that people seem to have little trouble with.

 

[Drunkskunk]

Will LiPo spontaneously ignite if charged properly, maintained and not abused?

It can, if there is a defect in the pack. It might be a problem right away, or it might not fail untill it's 300th cycle.

I've found RC packs weeks after being used suddenly swolen and warm. The chemical reaction inside a lipo is never dormant. The battery is never "off". Thats true of all batteries, but Lithium Cobolt has the ability to self ignite. A rare occurance, but always a possability even without abuse.

Most cellphone and camera batteries are using LiMn or LiMnCo lipo, which is more stable and much less likely to self ignite.

Lipo aren't to be feared or hated. But they have to be respected. Since most people assume a battery is safe, the resspect isn't there. But you can't treat a lipo like any other battery. Everything a novice knows about batteries has to be thrown out and they have to learn new habbits and new respect for the dangers involved. And it takes some technical skill to recognise some of the dangers.

 

[LI-ghtcycle]

OMG John!

I've never heard of that happening. Some crazy impurity mfg defect in the cell?

I'm so sorry John! I'm glad it didn't burn your awesome guest house down.

Nothing to be sorry about, I pretty much expected to lose at least a pack or two out of that group, and no real harm was done. I just never expected it while it just sat there.

Netronix,
I've got 15 of the Turnigy 20C hardpacks, 4s5ah. I've had them a little over a month, and all I did was bulk charge them 5 packs in series at a time to 81V with my ebike charger that I use for my 20s Konion packs. A day or 2 later I checked each pack for balance at the cell level, and all packs were fine at 4.04v to 4.06v per cell. That all took place in the first few days, and after everything seemed fine a week or so later, and I took them off the ceramic tile floor and put them on the desk where they sat out of the way, unused and untouched for several weeks since. It's rained a few times in the past week, so the humidity has changed a bit, but there definitely aren't any leaks in that room, so they didn't get wet. The only other change has been the daily change in temp, and it's been cooler than when Luke was down last year, so the range has been pretty typical with lows about 21°C (70°F) and highs of 26 or 27° (81F)

Bulk charging is not a good idea IMHO especially with cheap LiPo, so yes, cheap LiPo used in a way it wasn't designed (bulk charging) is asking for trouble.

Has this been the case with the high end LiPo too?

I mean, sure there have been problems with Lithium batteries of several combinations, and if you have a high voltage/wattage pack, that much electricity is in of it's self dangerous no matter the chemistry, however, I feel it's the user that has to learn to respect it just like I make sure there isn't a gas can near when I grind metal.

 

[LI-ghtcycle]

Amped Bikes sells a battery tube with LiCo, the Chevy Volt uses this same basic formula IIRC, and not to say that it can't have problems, but statistically, how often has one of the newer tech LiCo cells had one of these spontaneous thermal events that was never bulk charged or abused?

And to further ask the question, I am really honestly wanting to know the dangers of these packs, because so far I'm still seeing these problems in the low cost LiPo of yesteryear's formula.

http://endless-sphere.com/forums/viewtopic.php?f=14&t=27494

Here are some quotes from the above link to ask this question:

[

WTF???
Is is possibly john that the gauge that tells you its charged was reading low and you overcharged it with out knowing????

Hey Arlo... Are they these pack you attempt to buy on HK at 0.29$ per wh??[/quote]


Yes, and the exact same pack I have 64 of... in various flammable places....[/quote]



Could it be the reason why they offer them at low price :lol: ...


they normally call that FIRE sale !!! :x

is that what we should call C grade cells

Doc[/quote]

 

[John in CR]

I'm not so sure about laptops having the max danger types of cells after those initial reports of burned laps and houses. The couple I opened up were LiMN.

It looks like some of you are getting complacent again, so here's a little reminder of what can happen with lipo even without breaking a single one of the lipo rules. This battery pack was checked for balance upon arrival from Hong Kong. The pack sat unused and undisturbed for over a month with no direct sunlight in a room where the temperature stayed in the 70's, at least until the top cell in the pack decided to have a bit of fun.


At least I learned the lesson cheaply and without incident. Luckily it was the top cell that went, luckily I had the adjacent packs just far enough away, and luckily the guest house has an extractor fan running 24/7. 15 packs were sitting on a wooden desk along with about 400 A123 cells in a room with a wood ceiling. Had anything been different I'm sure the whole pack would have flamed out instead of just one cell and puffing the one below, which would have started a chain reaction of packs and certainly would have burned the guest house down.

I'll still use Lipo packs, but only because I can store my bikes and packs where they can do no harm even in a worst case scenario. I doubt that even 10% of lipo users have a housing setup to eliminate fire risk without pretty significant inconvenience.

 

[gensem]

Can I call my lipo charging "box" safe?

 

[MadRhino]

Yep, a safe charging place, and care habits, makes them perfect for ebike.
I read alot before taking a decision, and started with Lipo for my first build. It's a no contest, I would never go for anything with lower power density, for I consider weight a major issue for handling and performance.

Buying high quality cells is safer, never leave them when charging is safest. Then, it is also safe building the bike to make it quick battery release, for eventually burning a few hundred bucks of Lipo in a crash is not so bad when the bike is OK and ready to power with another pack.

I got a friend rid of 81 pounds of lead off his scooter, after making sure that he has a safe place to charge, and is conscious of the care he must have for his new battery pack. You should see his smile when I cross him on the street.

 

[John in CR]

Can I call my lipo charging "box" safe?

That's a lot of energy. If the wall and ceiling are inflammable, you're probably ok as far as burning the house down goes, though I'd worry about the wood floor. Some concrete or stone "legs" to lift the bottom of your storage bunker would put an insulating layer of air between it and the wood flooring. Make sure your smoke alarms are operational. Keep in mind that burying in dirt or sand is the only way to put out a lipo fire. If there are no kids or animals to disturb them and the packs are separable, I think it would actually be safer to have them on top of the stone and concrete pieces a bit further away from the wall and 5-6" separation between packs. That would limit any event to a single pack vs the bunker that would guarantee they all go shooting flames out around the edges of the lid.

Fireplaces are probably the best storage place, because they can obviously handle any heat and flames, but just as important will send the smoke up the chimney instead of filling the house. Another one I like is a stack of concrete blocks with a pack or two in each hole. That will limit how many packs are lost, which will keep the energy release lower and spread it over a longer period, since it will take much longer to spread to other packs if it does at all. You'd probably even have time to remove many of the packs and get them away from the event instead of adding to its intensity.

My one cell event wasn't even enough to flame out the cell below, but SoSauty's pack flameout at the recent race in California was pretty impressive. We didn't even know when mine happened, since no one was in the house at the time and the ventilation prevented any lingering smell. I went to work on something else and happened to notice the misshapen pack. I remembered smelling burnt plastic a couple of days prior, but figured it was just a neighbor burning trash, something still fairly common here.

I keep mine either on a bike, which is outside away from anything flammable, or on a ceramic tiles over concrete floor away from anything flammable and spaced almost a foot apart in the ventilated guest house.

 

[gensem]

Thanks for the comments John.

Im just using the box for storage now, lipos are new and never used yet. There is a ceramic floor piece between the lipos and the wooden floor and the walls and ceiling is made of concrete. When my shoulder finally heals I ll split the "box" in 3 parts having 2x 6s 8ah zippys in each. That way I dont need to unplug my 2p wire and I really dont mind losing 2 packs its burning the apartment building i live that bugs me.

What I did not find a solution yet is that the bike will stay parked inside my company parking lot with the batteries inside the frame bag and I cant use a brick there. -.-

maybe this

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10756

its not really fire proof, but it hold its own for awhile, besides you can make it really stiff.

 

[qtipslea]

LiPo is so confusing right now.

If only someone will do a calculator for us newbie. Input in the voltage you want, the AH you need, then BAM! Instant layout of what you need to buy including easy plug in harnesses and what not.

Then all one need to do is buy require materials, and hook it up. True plug and play?

 

[docnjoj]

Methods and IC57 come close to your needs. Check them out in the New items for sale section.
otherDoc

 

[amberwolf]

Will LiPo spontaneously ignite if charged properly, maintained and not abused?

Yes. Even if it is brand new. This already happened to John in CR as a documented case, and has probably happened to others that haven't posted it here for me to see.

I agree, there is a problem with low quality LiPo, and we still hear about puffed packs, a fire or two, but I believe this us due to operator error 90% of the time, packs don't puff unless you push them too far, and if you take the chance, charging them is really dangerous.

They come brand new shipped from the dealer/manufacturer as puffed, too often to discount as a one-off. It's a too-common (one in a hundred? a thousand? too often, either way) complaint here about packs arriving new with a puffed cell or more, already discharged to 0V.

 

[neptronix]

Here i go with my spiel again:

1) never overcharge lipo
2) never overdischarge lipo far below 3.0v & then try to use it again.
3) always run new lipo through a few cycles on a balancing charger & graph the discharge to see if you have bad cells that could lead to #2. This will also rule out cells that are bad from manufacture.
4) never discharge lipo at more than half it's rated C constant.. IE for a 20C pack, never run it higher than 10C constant.
5) never puncture the packs.
6) never let the cells sit at 90%-100% charge for longer than a few days.

Follow these rules and the chances of having a lipo fire is somewhere near winning the lottery or getting stuck by lightning twice.

 

[cwah]

Why is it a problem to leave the Lipo at 100% for a few days? I'm actually doing that very frequently

 

[neptronix]

Good question. I don't know specifics, but it has caused fires in the past.
If not causing a fire, it will reduce the cycle life of the pack notably to do so.
I'm sorry i don't have an electrochemical answer for you, but this is common knowledge on this board, and on many boards dealing with RC aircraft etc.

If you look at any lipo charger, there is always a 'storage mode' which discharges/charges cells so that they sit at approx. 3.8v.

 

[AussieJester]

Why is it a problem to leave the Lipo at 100% for a few days? I'm actually doing that very frequently

Same, mine are regularly above 4.18v for days
Been doing this since started wirh lipo in rc helis
Years ago. When I know the bike will sit for a week or
More I'll discharge the pack a lil, but this doesn't happen much as
the weather ain't usually bad for more than a few days
So the bike is mostly used daily, I bulk charge my 20c
Turnigys most nights, inside, whilst still in the bike, I'm
never more than A few meters away. Accidently bulk charged
Over half a dozen 22v packs on one occasion to over 4.7v
A cell....no fire just puffed cells, so, yeah, i'm not to concerned about lipo
And their fiery baby raping abilities.

KiM

 

[liveforphysics]

What you need to look out for, is low quality batteries of any type, and poorly designed pack construction (balance wires that can short and connections that can come loose etc)

When RC LiPo is pushed to the limits of how cheap a battery can be made, it's sacrificed a lot of quality control and safety etc. Same for anything that stores energy.


It's a risk each person needs to individually weigh the risks vs benefits, and choose what they can accept. If you can't accept ANY battery risks, then better get in shape, because you're going to be pedaling.

If you want good safety, I think the keys are to choose as quality of a cell as you can, with good consistency and QC (doesn't exist in RC), then construct a pack that has outstanding connection quality, durability, and layout/design of the current path. Then no-expense-spared on the quality of the wiring used for balance leads, and route them with strain relief and protection from chaffing on anything anywhere, and inside a protective fiberglass or nomex sleeveing. As far as BMS goes, there is nothing in the ebike price range that you're better off using than not using IMHO, but a failsafe setup to cut power if a cell group gets too low or cut charging if a cell group gets too high would be a damn good idea (like the thing Methods makes).

In enough time with enough people using them, it does seem inevitable we are going to see some fires with all the RC lipo packs, and it does seem like somebody is going to have a home burned down at some point. We still make up such a tiny percentage of the RC LiPo user group though, it's surprising to me that the RC world doesn't see more than the handful a year or so of car fires and little garage bench fires that we see.