BU-304a: Safety Concerns with Li-ion

Learn what causes Li-ion to fail and what to do in case of fire.

Safety of lithium-based batteries has attracted much media and legal attention. Any energy storage device carries a risk, as demonstrated in the 1800s when steam engines exploded and people got hurt. Carrying highly flammable gasoline in cars was a hot topic in the early 1900s. All batteries carry a safety risk, and battery makers are obligated to meet safety requirements; less reputable firms are knowns to make shortcuts and it’s “buyer beware!”

Lithium-ion is safe but with millions of consumers using batteries, failures are bound to happen. In 2006, a one-in-200,000 breakdown triggered a recall of almost six million lithium-ion packs. Sony, the maker of the lithium-ion cells in question, points out that on rare occasion microscopic metal particles may come into contact with other parts of the battery cell, leading to a short circuit within the cell.

Battery manufacturers strive to minimize the presence of such particles; however, complex assembly techniques make the elimination of all metallic dust a challenge. Cells with ultra-thin separators of 24µm or less (24-thousandth of an mm) are more susceptible to impurities than the older designs with lower Ah ratings. Whereas the 1,350mAh cell in the 18650 package could tolerate a nail penetration test, the high-density 3,400mAh can ignite when performing the same test. (See BU-306: What is the Function of the Separator?) New safety standards direct how batteries are used, and the UL1642 Underwriters Laboratories (UL) test no longer mandates nail penetration for safety acceptance of lithium-based batteries.

Li-ion using conventional metal oxides is nearing its theoretical limit on specific energy. Rather than optimizing capacity, battery makers are improving manufacturing methods to enhance safety and increase calendar life. The real problem lies when on rare occasions an electrical short develops inside the cell. The external protection peripherals are ineffective to stop a thermal runaway once in progress. The batteries recalled in 2006 had passed the UL safety requirements — yet they failed under normal use with appropriate protection circuits.

There are two basic types of battery failures. One occurs at a predictable interval-per-million and is connected with a design flaw involving the electrode, separator, electrolyte or processes. These defects often involve a recall to correct a discovered flaw. The more difficult failures are random events that do not point to a design flaw. It may be a stress event like charging at sub-freezing temperature, vibration, or a fluke incident that is comparable to being hit by a meteor.  

Let’s examine the inner workings of the cell more closely. A mild short will only cause elevated self-discharge and the heat buildup is minimal because the discharging power is very low. If enough microscopic metallic particles converge on one spot, a sizable current begins to flow between the electrodes of the cell, and the spot heats up and weakens. As a small water leak in a faulty hydro dam can develop into a torrent and take a structure down, so too can heat buildup damage the insulation layer in a cell and cause an electrical short. The temperature can quickly reach 500C (932F), at which point the cell catches fire or it explodes. This thermal runaway that occurs is known as “venting with flame.” “Rapid disassembly” is the preferred term by the battery industry.

Uneven separators can also trigger cell failure. Poor conductivity due to dry areas increases the resistance, which can generate local heat spots that weaken the integrity of the separator. Heat is always an enemy of the battery.

What to do when a battery overheats

If a Li-ion battery overheats, hisses or bulges, immediately move the device away from flammable materials and place it on a non-combustible surface. If at all possible, remove the battery and put it outdoors to burn out.

A small Li-ion fire can be handled like any other combustible fire. For best result use a foam extinguisher, CO2, ABC dry chemical, powdered graphite, copper powder or soda (sodium carbonate). If the fire occurs in an airplane cabin, the FAA instructs flight attendants to use water or soda pop. Water-based products are most readily available and are appropriate since Li-ion contains very little lithium metal that reacts with water. Water also cools the adjacent area and prevents the fire from spreading. Research laboratories and factories also use water to extinguish Li-ion battery fires. Halon is also used as fire suppressant, but this agent may not be sufficient to extinguish a large Li-ion fire in the cargo bay of an aircraft.

A large Li-ion fire, such as in an EV, may need to burn out as water is ineffective. Water with copper material can be used, but this may not be available and is costly for fire halls.

When encountering a fire with a lithium-metal battery, only use a Class D fire extinguisher. Lithium-metal contains plenty of lithium that reacts with water and makes the fire worse. As the number of EVs grows, so must the methods to extinguish such fires.

CAUTION Do not use a Class D fire extinguisher to put out other types of fires; make certain regular extinguishers are also available. With all battery fires, allow ample ventilation while the battery burns itself out.

During a thermal runaway, the high heat of the failing cell inside a battery pack may propagate to the next cells, causing them to become thermally unstable also. A chain reaction can occur in which each cell disintegrates on its own timetable. A pack can thus be destroyed in a few seconds or over several hours as each cell is being consumed. To increase safety, packs should include dividers to protect the failing cell from spreading to the neighboring one. Figure 1 shows a laptop that was damaged by a faulty Li-ion battery.

Suspected Li-ion battery destroys laptop


Figure 1: Li-ion battery suspected to have destroyed the laptop.
The owner says the laptop popped, hissed, sizzled and began filling the room with smoke.

Source: Shmuel De-Leon

The gas released by a venting Li-ion cell is mainly carbon dioxide (CO2). Other gases that form through heating are vaporized electrolyte consisting of ethylene and/or propylene. Burning gases also include combustion products of organic solvents.

While lithium-based batteries are heavily studied for safety, nickel- and lead-based batteries also cause fires and are being recalled. The reasons are faulty separators resulting from aging, rough handling, excessive vibration and high-temperature. Lithium-ion batteries have become very safe and heat-related failures occur rarely when used correctly.

Simple Guidelines for Using Lithium-ion Batteries

Last Updated 2016-05-13

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On November 3, 2011 at 4:50am
JasonsRobot  wrote:

Lithium0ion batteries are safest just because their manufacturing process and techniques are truly based of professional use. Its hardly you hear of any heat failure of it. batteries promise long life time come with high percentage of energy failure.

On January 16, 2013 at 2:58am
antoinecoca wrote:

Would anyone know which certifications and norms the Li-Ion battery must comply with when imported in Europe?

On October 28, 2013 at 4:04am
Maria wrote:


I would like to know if someone has data about how hot could a Lithium ion battery culd actually burn? (for large scale fires).

Tks in advanced.

On May 28, 2014 at 10:10am
Louis wrote:

Can I charge Li-ION 4500mAh 3.7V Battery with my “regular” Ni-Cd / Ni-MH RadioShack charger, if so what setting works the best, if any.


On July 19, 2014 at 8:07pm
Brendon wrote:

@Louis:  Definitely not!  Li-Ion is a very different chemistry from NiCd ard NiMH.  Each chemistry requires the use of a charger specifically designed for it.

On July 31, 2014 at 4:43am
j wrote:

We have a lithium fire extinguisher at work… how does it do it? DHL will send batteries by air somehow… there needs to be a way to send batteries safely…

On September 22, 2014 at 8:29pm
BB wrote:

someone played a joke on me by putting a lithium ion battery for a power tool in my oven.  I didn’t know and preheated my oven to 450 degrees before I smelled the plastic melting and discovered it.  How dangerous was this?  Could it have exploded and injured me??

On November 4, 2014 at 8:07am
Dan wrote:

@BB: You should immediately cease contact with that individual and surround yourself with more intelligent beings.

On December 2, 2014 at 2:12pm
Pillow wrote:

I recently got myself Gameboy advance SP and it has Lithium Ion battery. Since it did not come with charger, my dad tried to charge it with home-made charger, he crafted it using old nokia phone charger. Soon, when I was alone home, I discovered that the battery was a bit bigger than before and it was pretty hot. I unplugged it inmediatly and my dad said that he will see if he can charge it on safer way. I would like to ask, should I get the new battery? Is using the same battery dangerous even if it goes back to its normal size? What should I do?

On December 31, 2014 at 9:21am
sp00zer wrote:

Get a new battery right away. Changing physical size is an indication of internal chemical change in the direction of failure. A battery like that should never be reused inside of a device.

On February 18, 2015 at 12:48am
Thomas wrote:

I’m constantly bing told that water is the way to extinguish Li ion fires. And yet fire suppression companies sell class D extinguishers and say that water is NOT the way to fight these fires. What are the facts?

On February 26, 2015 at 10:36pm
Richard A. wrote:

I work for a company that exchanges fire extinguishers in buildings. There is a battery test lab for an automaker that I am iffy about the right extinguishers. They want an ABC, but wouldn’t a Dry Chem Sodium BiCarb be better due to the corrosive factors?

On March 23, 2015 at 3:33pm
Rich wrote:

For primary cells with Lithium, absolutely do no use water. The lithium will react with the water and you will have even more of an issue on your hands. So 1 use coin cells and the like, Class D extinguisher.

For Secondary cells, especially ones that are part of a pack.Put out the flame with pretty much any of the listed extinguishers above then you want to use water and a lot of it. The amount of lithium in secondary Li-Poly and Li-Ion cells is quite low and won’t react. Your goal with the water is want to drop the temp of the surrounding batteries so they don’t overheat and vent.

On May 2, 2015 at 1:38am
khan wrote:

my child put samsung phone battery 3.7 v in warm cup of tea that i drank. After realizing it, i hurried and took it out. Some white solid was already there at electrodes. Now i worry for health concern specially bcza i m 6 months pregnant. I m drinking lot of water and vomited as well. What kind of chemical would have released in so short time and what else can i do now.

On May 16, 2015 at 2:37am
roland wrote:

i`m no doctor and also no chemist, but i wouldnt worry.  the white solid is probably some electrolytic result of the current flow through the tea/liquid, as it can transport electrons. i`m sure, that no inner (or even poisonous) materials from the battery have leaked into the tea and your health is not at danger

On May 21, 2015 at 1:21pm
David wrote:

“If the fire occurs in an airplane, the FAA instructs flight attendants not to use fire extinguishers but the use of water or pop soda. Water cools the adjacent material and prevents the fire from spreading. Many research laboratories and factories also use water to put out battery fires… Li-ion contains no lithium metal and does not react with water (lithium metal batteries requires different extinguishing methods).”

Ok, so I’ve learned to use water, not fire extinguishers, and Li-ion batteries don’t react with water.

Then it says:

“Use a foam extinguisher, CO2, dry chemical, powdered graphite, copper powder or soda (sodium carbonate) to extinguish a lithium-ion fire. Only pour water to prevent the fire from spreading as water interacts with lithium.”

Ok, so now I’ve learned the precise opposite - to use fire extinguishers, not water, and Li-ion batteries DO react with water.

Very confusing.

On May 22, 2015 at 11:43am
Cadex Electronics Inc. wrote:

Thanks David, We have updated the article to clarify.

On June 5, 2015 at 7:28am
Terri wrote:

Has anyone heard of any Samsung SDI Li-Ion batteries used in HP Compaq recalls?

On June 25, 2015 at 5:07pm
Rod East wrote:

I am a serving professional Senior Fire Investigator and would like further infomation regarding the failures and way to identify the failure within the Lith-ion batteries.

On July 3, 2015 at 6:22am
raj wrote:

i have a blackberry MS 1 battery that has bulged and cracked.

Is it toxic to me or anyone around me to handle?
Are there any fumes that may be released?

Should I continue using it? It works fine, although the charge runs out quickly

On July 16, 2015 at 6:52am
Sue wrote:

Do lithium batteries leak out?  They seem so toxic I am concerned about having them in the clock radio that sits right next to my head all night!

On July 28, 2015 at 8:39pm
Erika wrote:

Can I use a lithium motorcycle battery in a fiberglass toolbox under the seat? Or is this a big no-no? Thanks.

On August 20, 2015 at 12:58pm
gary monroe wrote:

Does anyone know of a Lithium Ion Battery Handling Safety presentation (ppt) or onsite instructor-led course?  My company deals with Li-ion batteries in a big way and need a good battery handling course.

On September 12, 2015 at 8:50pm
Malia Skinner wrote:

i come down starts to find my tablet destroyed i threw it away cause it wasent working anymore and my tablets battery came out and my brother opens the battery and thosed it in the trash and came to get it i wasent expecting until my brother was holding it all of a sudden it got hot and the next thing the long battery ligt on fire what was the cause of this was it because my brother destoryed ot or long enough exposure to oxygen? please help me answer

On September 18, 2015 at 1:00am
n.z wrote:

what’s the range of moisture that li-ion battery can be safe when we want to open it?

On October 21, 2015 at 1:53pm
Robert Dubé wrote:

@gary monroe
I came across this while looking for battery info http://excellbattery.com/wp-content/uploads/2015/02/Safety-Presentation-FEB-2015.pdf
This company also have some training available, look in the top menu for training http://excellbattery.com I am not relate to the company and do not know about the paid trainings.

On November 26, 2015 at 4:31pm
Robert Irvine wrote:

Can a cell phone explode in a steam room at the gym some people are using them more frequently I think it may cause burns or worse please help

On December 4, 2015 at 2:11am
Tonawr wrote:

QUESTION. IF YOU’RE CHARGUNG YOUR LITHIUM BATTERY AND OVER 4.300 (the point of pressure buildup). will the pressure go away after taking it off the charger, or will that pressure stay there, making it able to explode anytime I begin charging it?

On December 11, 2015 at 3:32pm
Roger Bohn wrote:

Raj: Swollen, cracked, broken, or holed lithium batteries: treat them as dangerous! DO NOT USE; DO NOT RECHARGE. Even if they don’t burn your house down (happened to a friend of mine) they cause an unholy smell when they burn, which is very hard to get rid of.

Tonawr: Not sure what pressure you are referring to. Are you talking about the Amp-hour (charge) level? In that case, if you continue to charge past its rating it will eventually catch fire, but not because of physical pressure. Good batteries, and good chargers, are carefully designed to prevent overcharging.

On December 16, 2015 at 2:46pm
Craig Blair wrote:

Is there any way to be forewarned of a Lithium- ion battery’s eminent failure? Is temperature an effective way to predict it, or is it ONLY a matter of metal particles causing a short? IF temperature provides an effective warning, at what temp should one cease operation?

On January 2, 2016 at 9:00am
Deb Freed wrote:

my son has a hoverboard and I know there have been issues with them beating into flames.  How can I safely store the hoverboard so that a fire would be contained if it combusts while no one is home?  Would it be safest in the bathtub? Wrapped in a fire safety blanket? Placed in a fire safe (seems like an expensive solution)? Or do I just spend my life in a panic that my house will burn down when I’m not home?

On January 2, 2016 at 12:09pm
Roger Bohn wrote:

1. Most important, only charge it when someone is home and in the same room. Most fires occur when charging. If possible, charge outdoors. Also for some period after charging.

2. Store: on a concrete floor with nothing around (garage). Bathtub is ok but not very practical. Fire blanket is good.

3. When in any crash (which is probably common) - treat it as likely to go off for the next few hours. If the battery OR circuitry were damaged, such as a short circuit, a fire is more likely.  Good luck!

On January 2, 2016 at 2:28pm
Deb Freed wrote:

My brother suggests draining the battery (running the hoverboard until the battery is dead) and then storing it that way.  Would that eliminate the risk of spontaneous combusyion?  If so, that is a simple solution.  My son can just charge the hoverboard the next time he wants to use it (he will be away for several weeks).

On January 2, 2016 at 2:48pm
Roger Bohn wrote:

Yes it will reduce risk of combustion, but no, you do not want to do that. Draining a lithium ion battery reduces its life considerably. In extreme cases, you can ruin the battery.

He does have a very good point thought that you should store it at an intermediate charge level. Do not store fully charged, because that somewhat increases the risks as well as increasing the size of a fire if one occurs.

By the way, is there a better discussion board for discussing these boards specifically?

On January 4, 2016 at 12:06am
Dave Potter wrote:

The hoverboards and laptops are getting a lot of attention, what about the 18650 batteries used in flashlights and other small devices?

On January 4, 2016 at 12:15am
Roger Bohn wrote:

Good question. I have not heard of problems with 18650s, but on the other hand I refuse to buy the cheap ones because I expect that they have the same sorts of safety hazards.

I know there are some reputable companies - I think Panasonic is the main one. Panasonic makes the energy storage core; other companies then add the electronics. So a Panasonic core + cheap electronics is sti≥ll dangerous.

Maybe someone can research and provide URls .

On January 4, 2016 at 12:20am
Roger Bohn wrote:

I have written a short blog post on hoverboard battery safety. Visit Art2science.org
Comments and questions there are welcome

On January 4, 2016 at 10:03am
Ron Butler wrote:

As the “building block cell”,18650’s certainly possess a failure potential. Most of the available burn tests have been done using these cells.

On January 12, 2016 at 3:48am
Andy Lea wrote:

I have 4 cells in a waterproof case. Do I need to remove the cells to charge? The box is probably air tight. Do the cells need to vent gas?

On January 18, 2016 at 4:43am
paul dennison wrote:

On Saturday evening a 3000mA/h brand name Efest exploded in my e-cig in my hand. The room filled with thick smoke and several small fires were caused as the device took off like a rocket I was able deal with these.Clearly I breathed the smoke in, but the room and I were covered with black dust.  Is there any medical advise on what I should do now please?
Is there any legal advise?


On January 18, 2016 at 2:30pm
Roger Bohn wrote:

Smoke inhalation is potentially serious, but seek real advice. I got a small whiff once, and it aggravated my asthma for a day.

Can you say more about circumstances? Were you using it at the time? Charging it?

I also wonder why such a large battery was in the product. But I know nothing about e-cigs. 
Thanks for reporting this - I hope you will post this incident more widely e.g. on e-cig sites.

On January 19, 2016 at 12:52am
Bob Seaver wrote:

I have a cell stuck in my Nikon D5000.  If I sdrill a hole in it to gewt it out, is that dangerous?

On January 19, 2016 at 1:06am
Bob Seaver wrote:

The cell is identified by a label that says it is a li-ion cell.  It is tha standad battery thati is used ro power Nikon D5000s but not a Nikon product; so it resisted being inserted and is struck by friction in the camera body.  Sorry to be so vague, but this is new for me.

On January 19, 2016 at 2:55am
paul dennison wrote:

The e-cig WAS a “Nemesis” made of stainless steel approx 106 mm by 22 mm dia.
I was changing the discharged battery with one from charger designed for these batteries.
It exploded as I hand tightened the parts together. Later that day I experienced severe stomach pains,and on advice from NHS direct then from my GP I visited A&E.  I was given two blood tests My only symptoms were stomach pain and small burn on my leg.They found a minor infection in my kidneys and provided antibiotics for this, conclusion the pain and e-cig were unrelated. I took photos of the carnage which a can email if required,please provide an emaill address. Thanks

On January 19, 2016 at 9:42am
RB wrote:

Don’t do it!  Sticking metal into a charged battery is guaranteed to short circuit and cause a fire. 99%. At best it would destroy the camera. At worst, burn your hands and start a bigger fire.
  How about finding a site of Nikon camera people and asking them?

On January 19, 2016 at 11:47am
Roger Bohn wrote:

To Bob: To strengthen my message: NO!!!!! It’s really going to make a mess and perhaps start a fire. And destroy the camera. And burn your hands if you don’t drop it fast enough.
If for some reason you decide to do it anyway, please do it outside and not near any flammable material.

Physical damage to a lithium battery is the second big cause of fires (along with overcharging). In radio controlled flying, when a plane does a nose-dive, we treat the battery as “about to catch fire.”
  Good luck. I bet there is another way to get that battery out.

On January 23, 2016 at 7:34am
barbara cissell wrote:

Do you recommend charging a laptop ion battery to only 90% to prevent overcharging and exploding.I have heard this is a good number.Also,how low should I let it get down to before I plug it back in? Is 2% a good number? Thank you.Confused in Louisville Ky

On January 25, 2016 at 1:38am
Roger Bohn wrote:

Barbara, don’t worry about laptop batteries, assuming the laptop is made by a first or second tier brand name. They are MUCH safer, with electronics to protect against overcharging, over-discharging, etc.
Laptop batteries cannot be overcharged because of protection in both the battery and the charger. You will slightly reduce the life if you let them be fully discharged frequently, but they are intended to give a full charge from 100 down to 0.

Why the safety difference? Brand name: Cases of laptop fires get lots of attention. Also certification by UL laboratories. Also government regulation: the CPSC would get involved if there were persistent problems. Also tort law: fires would lead to lawsuits.

Fires of the hoverboards will lead to lawsuits, but I expect that the companies that made them will be hard to locate, and then will turn out to have no assets if someone wins a suit. Tort lawyers have a bad reputation, but this is an example of why they can be good for safety!

On February 8, 2016 at 4:06pm
Verena Jolly wrote:

Hi, I’ve bought a GPS tracker with a Li-ion battery that I wanted to use on my horse.  Having read the info here…it sounds like there’s a risk of it setting on fire/exploding and injuring/killing her, especially as it could be subjected to some forces if she were to squash it when lying down to sleep etc.  Can anyone confirm please if I’ve correctly understood the risks?  GPS trackers are commonly used on pets and they presumably have lithium ion batteries…so are they risky too?

On February 12, 2016 at 1:43am
subrata das wrote:

Drones, mobile phones, laptops, mobile appliances use LITHIUM batteries. Avoid using chargers that implement fast charging overnight. Avoid power extension sockets near sofa, living room carpet. CHARGERS should be kept in well-ventilated area.
Mr Ian Johnson, 74 technical expert, attended a course in Germany on operating drones, left three drone LITHIUM polymer batteries to charge on the carpet floor besides sofa. At 3am in just 2 hours 4-generation family house reduced to a charred state at Parry Avenue Singapore, June 9, 2015. He died of extensive burns in the corridor.

On February 21, 2016 at 8:41am
philico wrote:

The risk of lithium ion batteries catching fire occurs when the battery has current flowing into it, that is, when charging or when in use. When the Li-ion batteries are not in use, they should be as safe as a tomato in your fridge, right?

I would like an answer to this question: Being out of any device it powers and being non-operated upon, i.e. there is no current load running through it, has anyone ever witnessed a Li-ion battery spontaneously catching fire?

On February 21, 2016 at 10:16am
Roger wrote:

Philico it’s a good question. Sounds logical, but it’s wrong.  Most fires occur while charging, some when in use, but there are documented seemingly spontaneous fires. Typically after an accident that physically damaged the battery internally. But an air freighter was destroyed by fire in batteries that were being shipped and were not in use at the time, not even plugged into anything.

On February 21, 2016 at 10:20am
Roger wrote:

Philico, this is a case where quality matters. A well made battery won’t do this. But there are some unqualified manufacturers in China whose batteries can have micro defects that eventually cause a short circuit.

On February 22, 2016 at 11:04am
philico wrote:

Roger, your answer makes sense. Batteries even without any current load seem to leak charge, even though this residual leak is normally pretty small. Can it be the case where mechanical vibrations like those involved during transportation can help dissipate charge inside the battery? Or, maybe humid conditions can help create a path for current to flow internally? whatever it is, I wasn’t aware that even under such small perturbations Lipos can spontaneously ignite.

So far I’ve owned and operated hundreds of Li-ion batteries and in only 2 cases I witnessed slight bulging in two incidents, although this bulging was very gradual and over the span of months.

On February 22, 2016 at 11:15am
Roger Bohn wrote:

Hundreds of batteries with virtually no problem — I would guess you are using good brands? Why so many, if I may ask? Also, perhaps you discard batteries when they lose effectiveness?

Residual leakage - yes, good point. Fires in that situation are presumably due to thermal runaway of some kind.

Keep up the good results. Lipo fires ARE rare, but they can be so disastrous when they happen that it makes sense to be very careful.

On February 22, 2016 at 1:35pm
philico wrote:

Roger - Not really. I almost always buy non-brand LIPO batteries, mainly because they are cheap. This is across the board, even those meant to replace those in my notebooks, smartphones and tablets. Why so many? Because I’m a gadget junkie and also because as you mentioned, I like to keep my devices running by recycling their batteries. I’m also an electronics / ham radio enthusiast and some of these batteries power up many of my projects.

There are billions of LIPO batteries currently in service and I’m safely estimating x20 more retired or not in service. The chance of a battery catching fire is extremely low. If it wasn’t, airline companies would have banned carrying electronic devices on board by now. Who knows. It only takes one bad incident to cause such a ban but let’s hope we’ll never get there. The race is on to make LI-ion technology fire safe.

On February 23, 2016 at 5:41pm
Ron Butler wrote:

Philico Roger is correct. The state of charge has a bearing on the potential for thermal runaway. However, failures can occur even if the SOC is approaching 0%

On February 23, 2016 at 10:58pm
philico wrote:

Ron - Can you please translate things into simple English so that our non-technical fellow readers can understand?

On February 23, 2016 at 11:36pm
philico wrote:

I’m not trying to refute the validity of this article or the fact that Lithium ion polymer batteries can’t catch fire. However, quoting you statement “In 2006, a one-in-200,000 breakdown…”, it tells me that the likelihood of your smartphone being struck by a lightning is probably higher than catching fire from the battery it carries! Of course, if you are so eager to prove me wrong by going as far as driving a nail though it then by all means you should be my guest and do it.

On February 24, 2016 at 10:59am
Roger Bohn wrote:

Philico, I think we agree. Just to be clear I make a distinction between:
Name-brand cellphone and notebook batteries. They are very reliable.

Bare, off-brand Lipos such as used for hoverboards and hobbyist use. They are NOT very reliable.

Partly it’s the batteries themselves; partly it’s the circuitry that monitors them when charging and discharging. So excellent safety of cellphones does not tell us much about hoverboards. For someone not familiar with them, buy only name brand equipment.

On February 24, 2016 at 12:25pm
philico wrote:

Roger - If you look at the capacity of cellphone and notebook batteries, you will notice a conservative behavior by manufacturers of using lower mAh values which makes me suspect that the polymer used is less densely packed and that probably makes things inherently safer. After all, its not the end of the world if you have few hours less until you plug that power cable back to the device. In addition, smart devices usually employ sophisticated software to conserve power. However, with equipment that require a lot of power such as power tools, hoverboards or drones, having a less powerful battery or trying to conserve power is not an option. So the risk of fire is presumably higher.

Another issue to be noted is that in their effort to compete with brand names, manufacturers of non-brand batteries often increase the capacity of a specific model by offering higher mAh values for a lesser price than the brand equivalent. People often fall for this. The issues I expect to see are higher failures and/or lower lifetimes although I have no evidence to back my claim. Can anyone help clarify?

On March 17, 2016 at 6:22am
Ted wrote:

Hi, we had a very sceary situation when my friend and i was replacing a iphone 6 battery. the battery is glued in the back cover and we had to bend it to get it of. Suddenly the battery sonded like a rocket engine and cought fire, the whole phone was destroyd.
My question is, would emptying the battery before replacing it had prevent this?

On March 17, 2016 at 11:01am
Roger Bohn wrote:

Ted, thanks for posting this. What you did will almost always cause a fire, because bending the battery breaks it inside, causing a short circuit.

Emptying the battery first would have reduced the size of the fire but the phone probably would still have been destroyed.

Whoever sold you a replacement battery, without warning about the hazards, should refund your money. Since it is an iPhone 6,  it should still have been under 1 year warranty anyway.
The best way to deal with a dying battery these days is to get an external plug-in battery. Don’t touch what is inside the case.

On March 18, 2016 at 10:31am
philico wrote:

Ted - I always fully drain the battery before I replace it from the device and I’ve done that many times so far without any fire hazard issues. I also ground myself while working on the device and battery. An empty battery has no active charge in it and if no charges get transferred or mechanically generated while removing it, it should be safe to handle. When you handle exposed electronics it is a good practice to ground yourself to avoid any static charges transferring that may damage the circuit. In a similar fashion, you may want to ground yourself when handling LIPO batteries especially those that are not shielded by a metal case to avoid any static charge buildup that would cause it to catch fire.

On March 18, 2016 at 12:16pm
Roger Bohn wrote:

Hi philico, you are more experienced than I and also more optimistic. I assume you are talking about batteries that are designed to be removed and replaced. That does not cover iPhones, nor most modern notebook computers, which have “integral batteries.” I considered replacing the battery on my Macbook Pro, for example, but it costs $700 because the keyboard and other circuitry has to be replaced at the same time.

Regarding zero charge state: ?? For the batteries I work with, they never reach zero charge, because if you let them get to that level it ruins the chemistry. I believe that similarly the charge/discharge electronics in a phone shut down the power before it reaches physical zero on the battery. I know my hybrid car battery works that way. Even at “zero” it can still start a fire.

On March 18, 2016 at 11:43pm
philico wrote:

Hi Roger - I don’t understand your point. Why do you worry about ruining the chemistry of a battery that is to be replaced? Personally I don’t since the batteries I replace are, well, dead or almost dead and if they are not, I make sure they get there… Sorry, I’m not a fan of Mac devices for the reason you indicated in your answer. As far as your claim that “even at a “zero” it can still catch fire”, well, do you have any substantiated proof?

On April 23, 2016 at 3:03pm
Alec Heesacker wrote:

We personally need non explodable batteries in laptops, psp, 3DS and phones.
I don’t want to have to spend thousands of dollars to repair or replace my electronics, if I’m going to Alaska.
I would recommend no lithium on the air port.
Haven’t you tested the batteries within high altitude?

On May 24, 2016 at 8:23am
Daniel wrote:

Is an exploding cell phone (LiPo/Li-ion) battery capable to blow op an ATX case (computer housing)?
Because of the vents it might not totally fireproof, but that is not really my issue if I put it in such a way that the blowup flame (I don’t know what the correct English word is) can’t set anything on fire.
My issue is that when it explodes it shouldn’t “fly” anywhere, because the wallls of the ATX case prevent it from doing so.
Therefore I want to know if an exploding battery is not capable to blow up a computer case.

On May 24, 2016 at 3:06pm
Simon Gore wrote:

On a note of personal experience. I had a smart phone li-ion battery that was ‘killed’ dead by a ravenous phone. It would not recharge. On metering the output it had a low voltage (under1.5V) and immeasurably low current .It hadn’t been used for months. So as you do when your a curious bugger. I took it outside,with ample fire protection and fire extinguishing and committed the earlier mentioned nail penetration test. Blow me down the thing started to fizzle and sputter with rank burnt plastic smoke and a tiny sustained fire. .no surprise to many of you I’m sure. Lesson 1) A ‘dead’battery can still produce enough current to ignite it’s internals when punctured .Observing the ‘arc’ more closely I could see the discharge was across small terminators from one cell division to the other. So I stabbed the battery multiple times to see what happened. No not a quicker bigger fire,but the cells had been disconnected across the battery and it was no longer able to generate enough current to arc/ignite.Lesson 2) The one break will cause fire.Many breaks will disrupt sufficient current flow.  All that said and done with many rolling eyes. Would this be a suitable method in battery design.When the heat gets OTT (thermal runaway) the cells connections disintegrate limiting available current ??  Just a thought? Any designers here ?