Exploding Battery pack - CREE XM-LT6 LED Bicycle Light

CitizenLee

Ouija wrote:

It's got nothing to do with the chargers, it's the lithium ion batteries that have a capacity to explode. Any Li-Ion battery can do it, irrespective of make, model or type (though some manufacturers go to greater lengths to prevent it than others). That's why they opted out of using them in the new Airbus (or was it the Boeing one, i forget). The Li-Ion batteries in your laptops can explode and so can the ones in your uber expensive torches, I-Pads, I-Phones etc unless steps are taken to prevent it.

I see your point Ouija, but I think if you buy from a reputable brand then the chances are at least lessened.

Also, surely a crappy charger can supply too much current or cause overheating, even if charging decent batteries?

homers double wrote:

Well yeah, but I would expect the likes of Apple to go to those lengths. Thats why I don't buy cheap shoot and live a care free life.

Apple are just good at marketing overpriced crap to idiots who fall for said marketing. There's nothing actually special about their products, certainly nothing a rival product can’t do better and usually cheaper.

Their batteries explode too...

See here and more here

Ouija

Apples are made in China. But it wouldn't really matter where they are made, Lithium Ion is inherently unstable. Even if you feed it the correct voltage at a moderate ampage a lot of lithium Ion batteries that have been mistakenly overdrained can start a chemical reaction that emits heat and then explode.

I suspect a lot of the explosions aren't caused by overcharging as most chargers for Lithium Ion batteries have overcharge prevention circuitry (even the cheap Chinese stuff). It's probably caused by batteries that have been drained or left for a long time without being charged (allowing them to drain) and then most people attempting to charge them. When they don't charge in their usual time frame they figure they'll just go away and leave it a bit longer and they'll eventually charge, failing to notice the usual warning sign that the batteries are warm to the touch....... boom. Most of the cheap Chinese chargers can tell when the batteries are near to full capacity but can’t tell when a battery is failing to take any charge whatsoever so just keep pumping juice into them getting them warm enough to trigger a runaway chemical reaction who's bi product is heat.

bennett_346

Ouija wrote:

Apples are made in China. But it wouldn't really matter where they are made, Lithium Ion is inherently unstable. Even if you feed it the correct voltage at a moderate ampage a lot of lithium Ion batteries that have been mistakenly overdrained can start a chemical reaction that emits heat and then explode.

I suspect a lot of the explosions aren't caused by overcharging as most chargers for Lithium Ion batteries have overcharge prevention circuitry (even the cheap Chinese stuff). It's probably caused by batteries that have been drained or left for a long time without being charged (allowing them to drain) and then most people attempting to charge them. When they don't charge in their usual time frame they figure they'll just go away and leave it a bit longer and they'll eventually charge, failing to notice the usual warning sign that the batteries are warm to the touch....... boom. Most of the cheap Chinese chargers can tell when the batteries are near to full capacity but can’t tell when a battery is failing to take any charge whatsoever so just keep pumping juice into them getting them warm enough to trigger a runaway chemical reaction who's bi product is heat.

I fully drained two 18650 cells two weeks ago, are they safe to charge?

HebdenBiker

I have the same battery pack. Mine didn't explode but I drained them (in an experiment to find out how long they'd last) and now they won't charge properly.

I'm going to buy four new protected 18650 batteries and fit them to the battery pack.

Can any sparkies or physicists out there reassure me that this will lead to a more reliable (and less dangerous) setup?

Ouija

bennett_346 wrote:

I fully drained two 18650 cells two weeks ago, are they safe to charge?

Depends if they have protection circuits on them. If yes, the circuit probably cut in to stop you draining them completely and it's safe. If not then you can charge them but it's a good idea to keep an eye on them and keep checking to see if they are getting overly warm to the touch. A fully drained Li-Ion battery can get stuck and refuse to start charging (causing the overheating and occasional explosion mentioned above) but you can sometime kickstart such a battery back into life by charging for a while, turning the charger off, charging for a while etc until the battery appears to be charging (test the battery in something like a torch).

j_l

chick0 glad you didn't come of too badly, do you have smoke alarms fitted in your house?

One of the most common cause of house fires in the uk is battery chargers / battery's failing and exploding, like mobile phone chargers etc, that's the main reasons you should never charge your mobile at night next to your bed at while you sleep (I know a lot of you do)....

The most common is arson........

bennett_346

J L wrote:

chick0 glad you didn't come of too badly, do you have smoke alarms fitted in your house?

One of the most common cause of house fires in the uk is battery chargers / battery's failing and exploding, like mobile phone chargers etc, that's the main reasons you should never charge your mobile at night next to your bed at while you sleep (I know a lot of you do)....

The most common is arson........

I leave mine charging by the bed. Oops. Didn't know that. That's a frightening statistic regarding arson though, i regard that as one of the worst violent crimes there is since a) it can kill and b) it destroys your property.

Ouija wrote:

bennett_346 wrote:

I fully drained two 18650 cells two weeks ago, are they safe to charge?

Depends if they have protection circuits on them. If yes, the circuit probably cut in to stop you draining them completely and it's safe. If not then you can charge them but it's a good idea to keep an eye on them and keep checking to see if they are getting overly warm to the touch. A fully drained Li-Ion battery can get stuck and refuse to start charging (causing the overheating and occasional explosion mentioned above) but you can sometime kickstart such a battery back into life by charging for a while, turning the charger off, charging for a while etc until the battery appears to be charging (test the battery in something like a torch).

I'll give it a go supervised, i have no idea if they're protected. There was no mention of it in the listing so i'd assume not. Best way to do this safely may be in the basement as it's all bare concrete and there isn't as high a risk if it goes pear shaped, but i'll keep an eye on them as they go.

Mojo_666

This is why i got rid of all my cheap china specials and got decent lights.

Ouija

Mojo_666 wrote:

This is why i got rid of all my cheap china specials and got decent lights.

Which probably run off Li-Ion batteries also........


It's a bit like saying the gasoline in your expensive Ferrari is less explosive than the gasoline in some other persons Mini simply beacause it's in a better machine. Makes no difference what you've got it in.... gasoline is gasoline and lithium ion is lithium ion. Unless you change it's fundamental property gasoline will always have the capacity to explode and lithium ion will always react badly to overdraining/overcharging.

Northwind

Yup. My mate's Hope battery pack blew up similiarly (though it's a more enclosed pack so didn't fire bits around in the same way, it still burned a nice hole in the floor) and another mate's Exposure charger melted in the socket- luckily the fire didn't spread as he did it in the kitchen.

We take electrical stuff for granted but it can still bite you.

CitizenLee

We have a house full of li-ion battery powered devices...

5 mobiles, a tablet, loads of mp3 players, various game controllers, a few torches, bike lights etc etc.

I'm actually scared now :?

cooldad

I am surrounded by 19 at the moment. I use them to vape, with home made coils.
Mainly unprotected as otherwise I can't get the amps for low resistance coils.

You only live once.

Mojo_666

Ouija wrote:

Mojo_666 wrote:

This is why i got rid of all my cheap china specials and got decent lights.

Which probably run off Li-Ion batteries also........


It's a bit like saying the gasoline in your expensive Ferrari is less explosive than the gasoline in some other persons Mini simply beacause it's in a better machine. Makes no difference what you've got it in.... gasoline is gasoline and lithium ion is lithium ion. Unless you change it's fundamental property gasoline will always have the capacity to explode and lithium ion will always react badly to overdraining/overcharging.

I though it was like saying I expect well knows brands to make things better and to be held to a higher standard (or just a standard) and that the component parts are assembled better with in built checks and ballances? I had 4 china special torches and 3 lamps, my chargers over heated batteries and torches failed, I also resorted to charging in a tin in the middle of my garage, through a life time of owing various elictrical gadgets with chargers I have never had a battery blow up, a charger crackle or over heat (until i got my china specials) now I am back to where I was living in safesville.

cooldad

Simple solution - decent batteries and proper chargers.

chrisrobs

Ive got the same lights and I think there bang on for 28 quid, my mate has an expensive magic shine set but mine always last longer on rides (at night).

bennett_346

cooldad wrote:

You only live once.

Exactly - may as well make sure it's as long as possible then!

cooldad

bennett_346 wrote:

cooldad wrote:

You only live once.

Exactly - may as well make sure it's as long as possible then!

Yep, sell your bike and take up knitting. Just be careful of the pointy bits.

Woody80

Does anyone know if the branded/expensive battery packs will work with an eBay special light? Are they standard connectors? Mine has decided to drastically curtail it's output and plunge me into darkness at the most inconvenient of moments! Luckily I have 2 so didn't get eaten by unseen that lurk on night rides....

I would ideally just buy another battery pack and it might be best to upgrade?

homers_double

100% depends on the fitting I suppose. Isn't 12v 12v? I'm not an electrical engineer but the LEDs board controls the lamp output.

Northwind

The connectors are fairly standardised now but there's still exceptions. Torchy The Battery Boy sells a battery pack that's compatible with most Magicshines.

Having said that you end up paying £30-£40 for a battery, so at that price it's tempting to look at complete lights.

bjl

Off topic again , I have one of the Chinese Cree front lights, it was working ok but only lasted about 1 hr on full beam . Charged it up the other day but put batteries in wrong way round , the light won't work at all now, I bought another set of batteries from ebay and they aren't working either , any ideas what has happened and what I can do ?