lithium batteries?

[look 171]

Just how safe are these lithium batteries. I have them in my flash lights, drill motor batteries (my men sometimes keep them charge over night at clients' home when they leave) and cameras. I read about them busting into flames, what are the chances. I worry about the ones that are cheap Chinese made for my flashlight. I think that are all made there?

[slodave]

Lithium Ion batteries are pretty safe, but do fail. Lithium Polymer batteries are very prone to failure and will explode/combust. Almost all the "Lithium" batteries in consumer items are the Ion type.

[look 171]

When you say fail, you mean they still burst into flames, right?

[slodave]

Um, yes...

In fact:
http://www.businessweek.com/news/2011-11-29/gm-s-volt-battery-fires-threaten-to-knock-moon-shot-off-target.html

[Brown747]

Safe?? Not so much...


ASN Aircraft accident Boeing 747-44AF (SCD) N571UP Dubai Airport (DXB)

ASN Aircraft accident McDonnell Douglas DC-8-71F N748UP Philadelphia International Airport, PA (PHL)

Crashed Asiana 747F Had Fire On Board | AVIATION WEEK


http://www.faa.gov/about/office_org/headquarters_offices/ash/ash_programs/hazmat/aircarrier_info/media/Battery_incident_chart.pdf

[widgeon13]

Can they be made to fail? If so you would believe that the bad guys are working to put this to their advantage.

[crustychief]

I use Lithium polymer batteries in R/C airplanes. I have had them burst ( due to misuse ). They are pretty safe if used / handled as intended.

[Scott R]

Didn't Sony have a bunch of Lion batteries in laptops that caught fire?

[Hugh R]

We lost a camera truck and about a million dollars worth of camera equipment due to an overnight fire caused by them charging.

[love911]

While charging my IR mouse ,I smell this horrible burning odor and smoke coming out of the battery comp. I disconnected the charger immediately, and looked inside,and saw one of the battery was busted open and smoking,I'm sure if I wasn't there it would have caught fire.

[look 171]

it sounds like these battery usually burst into flames during charging not sitting idle in a flashlight or a drill connected to both terminals. I am a little worry about leaving a drill charging in a client's million dollar home. I do not want the bill on that one or someone getting hurt.

[RWebb]

risk is low

[Aurel]

I have been working on Li-ion batteries for over 15 years. There are many cathode chemistries, cells designs, sizes, electrolytes...Some are safer than others. For instance, LiFePO4 is safer than LiNi0.8Co0.15Al0.05O2, and LiNi0.33Co0.33Mn0.33O2 has a good compromise of safety and performance. There are electrolyte additives that prevent ignition, separators that shut down.

Problem is, it is very difficult to pack a large amount of energy in a small volume and be totally safe at the same time. All it takes is a short, local heat elevation, and thermal runaway can happen. It is the battery pack design and electronics that can mitigate the effects too. And of course, the bigger the battery, the bigger the consequences.

In the case of Chevy Volt, fires have occured 1 week after a crash test. I say, this is still better than a gas tank exploding during the crash.

Cheap chinese Li-ion batteries have been known to be more dangerous than higher quality japanese or Korean ones. Quality control, cell homogeneity are key to build reliable packs. Hand made cells in chinese sweat shops, not so good...

In fact, I published the very first paper on the reactivity/safety of graphite anodes in Li-ion batteries., during my post-doc.

[look 171]

So, if you leave then in a flash light, and the light isn't on, chance if it catching fire is slim?

[Aurel]

Originally Posted by look 171

So, if you leave then in a flash light, and the light isn't on, chance if it catching fire is slim?

Yes, very slim. Most fires happen during charging, when an overcharge situation exists, or during high power discharge that causes overheating.

[nota]

so I should not charge a E-cig over night ?
it calls for 2-3 hour charge plugged into a USB port charger

are single cells less a problem then multi-cell packs


btw are Li used to dead like a ni-cad or charge when ever used like a lead/acid
or something else ?

[crustychief]

Originally Posted by nota

so I should not charge a E-cig over night ?
it calls for 2-3 hour charge plugged into a USB port charger

are single cells less a problem then multi-cell packs


btw are Li used to dead like a ni-cad or charge when ever used like a lead/acid
or something else ?

NO! That is how I kill my batteries. I am only a user, not an expert. When the voltage drops below 3.7 volts per cell on the battery configuration I use, the battery will start to swell. Most chargers have a safety built in so they will not charge a "dead" battery, only a "discharged" battery.

[nota]

sorry if I am useing the wrong words

in R/C racing ni-cads are thought to work best
if discharged to dead [no juice at all]
not dead as in no longer will charge or shorted or something else wrong

while a lead acid battery works best and longest lived if recharged way before discharged fully

do li battery or cells need full discharge like a ni-cad
or constant recharge no matter the level like a lead-acid
or something totally different from both ?

[look 171]

Originally Posted by nota

sorry if I am useing the wrong words

in R/C racing ni-cads are thought to work best
if discharged to dead [no juice at all]
not dead as in no longer will charge or shorted or something else wrong

while a lead acid battery works best and longest lived if recharged way before discharged fully

do li battery or cells need full discharge like a ni-cad
or constant recharge no matter the level like a lead-acid
or something totally different from both ?

I was told by many people that sell then that it Li do not have memory no matter when you charge them. Is that truth. I personally do not believe them.

[RWebb]

not to get too OT here, but Aurel how does you do differential scanning calorimetry?