exploding batteries

[cheech226]

i've been lurking for a month or so and have seen references to batteries exploding. i've googled protected batteries hoping to find why and how they are protected. all i got were links to sales. will someone explain why a battery would explode?
i'm an old hippy astronomer who bought a greenie for pointing. got hooked on lasers right then. i'm anxious to learn all i can.

 

[LarryDFW]

cheech226;

Battery cells can store a lot of energy when charged.

As this energy level and energy output has increased,

the cell is subject to heating from abnormal abuse.

High power batteries are capable of fire or explosion.

I have blown up a lead acid car battery without any abuse.

Lithium primary (nonrechargeable) cells can ignite.

NiMH power cells can catch fire under extreme loads.

Lithium-ion cells can vent if they get extremely hot.

The venting material can also catch fire.

U.L. has a series of abusing tests they run on lithium-ion rechargeables to insure long-term safety.

These U.L.#1642 tests short the cells, subject them to high temperatures, overcharge them, and other apply other damaging conditions.

Name brand cells like Sanyo/Panasonic, Samsung, Sony and LG have passed this rigorous testing.

IMO, the U.L. testing gives the user safer cells for Lasers and flashlights.

I have not been impressed with safety of inexpensive "protection circuits" I have seen on most Chinese cells.

LarryDFW

HAPPY Independence Day

 

[cheech226]

thanks larry for telling me not to trust the protected ones. i recently received a 200 mw 660 rayfoss with a green 18650 labled 3.7v 2000ma. don't know if it protected or not. i will order a name brand bat immediately. the charger that came with the laser should work well as it's the "same" battery.

 

[weeba2kv]

@ LarryDFW
Sorry but , are protected cells good or bad ?

 

[Lotus_Darkrose]

Protected batteries are good IF the protection circuit is to be trusted.

Here's a link to a personal exploding battery experience (not mine)

Ultrafire 18650 3000mA exploded

 

[00Giorge]

I use Lithium-polymer batteries in my RC car and helicopter and keep them stored in a special charging bag that is fire and explosion proof. I do the same with the batteries for my lasers. I have seen batteries that have exploded or caught fire from using the wrong charge or over discharging. Always make sure to use the right charger or charge to avoid from this happening and do not over discharge your batteries as you will get the same results.

 

[HaloBlu]

Fire and explosion proof charging bag? Was it very costly?

 

[Shadowspawn]

Fire and explosion proof charging bag? Was it very costly?

They aren't too bad. I think they have been discussed here before, which is how I found out about them.

Amazon.com: Li-Po Charge Protection Bag, Small: Toys & Games

Amazon.com: LipoSack Fire Retarding Lithium Polymer Battery Charging & Storage Safety Bag: Toys & Games

 

[HaloBlu]

Thats not bad. Through I notice they are all advertised as for li-po. Which is worse again, li-po or li-ion when it comes to fire & explosions.

 

[LarryDFW]

@ LarryDFW
Sorry but , are protected cells good or bad ?

My experience with several hundred 18650 cells has been that "name brand" 18650 cells that have passed U.L. #1642 are less dangerous than . . .

non U.L. cells with protection circuit boards.

LarryDFW

P.S. Li-Po and lithium ion cells can both vent and catch fire when abused.

 

[BShanahan14rulz]

LiPo are electrodes and electrolytic separation material vacuum packed in a plastic bag of sorts. LiCo are electrodes and electrolytic separation material packed in a metal can. "They" say that the LiPo electrolytic is less prone to damage from higher currents due to the polymer separation material.

Both use the same chemistry, both can fail catastrophically. They are both lots of energy packed into a small space as chemicals. The circuitry lets the energy out of the chemical reactions slowly, but if you were to try to pull out all the energy too quickly, or stuff too much energy into the cell, those volatile chemicals can react violently. The PTC is only there to ensure that you get a face-full of fire and caustic chemicals, rather than a grenade with poisoned pieces of shrapnel. In the best of failures, the PTC will disconnect the cathode from the positive terminal to halt any further reaction before the gases ignite.

 

[cheech226]

thanks for all the good info folks!

 

[chipdouglas]

honestly your cells are as good as your charger. if you have a cheap charger, they can keep charging after your cells are full.

michael.

 

[Benm]

Those fire/explosion proofin solutions are fireproof socks of sorts - not true explosion containment devices at all.

Realistically the chances of a battery going explosive or catching serious fire are very limited, but its a good precaution not to charge batteries unsupervised. If something does go wrong, you'll be around to control the situation, which may be as simple as placing a cooking pot over the defective battery and charger to contain any fire.

 

[cheech226]

oh, and why don't batteries recharge Instantly? ;-) just received a 1.2w 445 from yob, the bats are Still charging!

impatiently waiting,

cheech

 

[Jacob32123]

oh, and why don't batteries recharge Instantly? ;-) just received a 1.2w 445 from yob, the bats are Still charging!

impatiently waiting,

cheech

They could, but it would produce a lot of heat and in a lithium battery, that could cause an explosion