If unprotected 18650 batteries are dangerous, why are they on sale ?

[march.brown]

I have two unprotected 18650 batteries that I would like to use, but having read up on these (on CPF), I am a little worried that something drastic might possibly happen ... It seems that most of the problems occur when the batteries are in the charger, perhaps when the owner has left them alone (charging) too long ... Or in multiple cell devices where one cell has been more discharged than the others.

I only want to use these cells in a torch ... Not a super-power torch, only my Saik SA-8, my Solarforce L2i (lengthened), my Solarforce L2 (not yet received) or my recently ordered Romisen RC-U4 ... None of these torches is what I would call a super-power torch ... So, now I don't know what to do ... My charger is a Ultrafire WF-137 single cell charger.

Surely if the unprotected cells are as dangerous as people say (on CPF) then they should not be sold for using in torches ... I know that these cells are used in Laptop Computers and that there have been problems there, but that is in a system using multiple cells ... I have a friend with a laptop and it is continuously plugged into the mains when in use ... It is rarely (if ever) used on batteries alone, in fact I doubt whether it would work now on its batteries ... She doesn't use it often so it only gets used a couple of times a week for an hour or so each time ... It is now about nine years old and apparently still performs as she wants it to ... If this Laptop is using these problem cells then perhaps she has just been very lucky so far ... Sometimes though, she leaves the laptop on for a few days just to charge the batteries ... She is in her seventies and won't listen when I have told her to use it instead on battery only ... Perhaps I should tell her about these dangers ?

The two unprotected Ultrafire (blue) 18650s as yet uncharged by me, are both reading 3.69 volts according to my old Avo 8 ... My two Ultrafire (grey) which were charged yesterday are reading 3.7 volts ... I can't guarantee the absolute accuracy of the old analogue meter ... Since I have just received the blue (unprotected) ones, is it safe to fully charge them now ? ... When I use them in a torch, do I estimate when they should be recharged or do I have to bring the torches into my study regularly just to measure the voltage ? ... Do I wait till the LED torches containing the unprotected cells are starting to go dim before recharging ? ... At least with the protected ones there should be a point at which the LED goes out but still leaves the battery safe (I think).

Perhaps someone could point me to the best thread that covers these queries ... Maybe with reference voltages giving predicted remaining power in the cell ... There may be other relative newbies that are also a bit worried about the transition from old battery technology to these new (to us) cells.

I hope this thread makes some sense to the advanced torch user ... "We newbies got to start somewhere".

Many Thanks.

 

[amigafan2003]

Car are dangerous.

Mountain bikes are dangerous.

Matches are dangerous.

Fireworks are dangerous.

Angle grinders are dangerous.

But yet they are all still on sale.

BUT they are all only dangerous if they are improperly used - the same applies to 18650's - if they are used properly they are almost perfectly safe - if misused then they are going to bite you in the ***.

People need to take some personal responsibilty over the products they are using. You can't legislate for stupidity - think of it as natural selection.

 

[Niconical]

Check the voltage before charging and after charging.
Charge them away from anything that might go
The moment you notice a dimming of output, remove and charge. (Ideally earlier than that though).

As for the laptop batteries, the cells are unprotected, but the battery pack is not. A protected cell (like from AW) is a cell, with a protection circuit added. A laptop battery is a bunch of cells with a protection circuit covering them all.

Voltage/remaining capacity - A rough guide, not a set-in-stone rule.

4.2V = Full
4.1V = 90%
4.0V = 80%
3.9V = 60%
3.8V = 40%
3.7V = 20%
3.6V = Empty
(voltage is measured open circuit, the DMM leads on the poles with no load on the battery)

(Not my figures, copied from another thread).

 

[SilverFox]

Hello March.brown,

Batteries store energy, and stored energy, under the right circumstances, can be dangerous.

Most people use Li-Ion batteries in devices that are designed around them, and the circuits in these devices have protection built in to insulate the average user from the dangers associated with the batteries. Taking some single cells and putting them into use in a flashlight that does not have these safety circuits designed into it exposes the user to an additional level of danger.

When you use cells that have a protection circuit built in, you still have to be cautious with their use, but when you use bare cells, you are the protection circuit. There is nothing backing up your decisions, and if you make the wrong decisions, there can be consequences beyond simple cell failure.

If you understand the parameters involved in Li-Ion technology, and are diligent in monitoring, you can use bare cells and will not have any issues. However, if you have a lapse in diligence, you will have to pay the consequences.

On the other hand, if you use protected cells, a lapse in diligence simply results in the protection circuit kicking in.

When starting off with Li-Ion cells, I always recommend doing a run time test. Once you have an idea of how long the light will run on a fresh charge, you can simply keep track of how much you use the light and charge it before it becomes completely discharged. If you loose track of how much you have used the light, pull the battery and charge it up and start over again. Or, simply measure the open circuit voltage to get an idea if it needs to be charged.

Tom

 

[old4570]

Some common sense will go far ...

For single cell use , there not that bad , 2x , thats different .

 

[paulr]

March Brown, I don't know where you're posting from, but there are a heck of a lot of products that are not marketed to consumers anywhere in the USA (at least through large retailers), because of liability issues etc. You can buy unprotected li ion cells from industrial distributors, but that's different, the idea of those places is that you're designing them into OEM products and you know what you're doing, it's not really a consumer market. You can also buy them from consumer-oriented web sites overseas, from vendors that are basically immune to any consequences of the cells exploding and causing you damage or injury, so they have no disincentive to taking your money. You can also buy just about any type of counterfeit product from those places, as well as stuff like pet food or baby formula containing melamine or children's toys made out of poisonous cadmium, to name just a few examples that have made news in recent times. Think of it as the genius of the free enterprise system when all accountability is removed. If you can buy something internationally that you can't buy domestically, there might very well be a good reason for that.

Does that answer your question?

 

[LeifUK]

Can you buy unprotected LiIon batteries in the UK? Not on the high street I bet. From what I have learnt here, they are potentially very dangerous, and need to be looked after. One part of that is using a charger with protection.

It looks as if they originally formed part of battery packs in laptops and other devices, and the packs included protection circuits. Then someone started selling them loose, without the protection. I don't see any big names such as Panasonic selling unprotected cells which should tell you something i.e. they don't want the possible bad publicity. So you buy them from China and other places and the brands are unknown. It looks to me as if they are used by hobbyists rather than mainstream consumers. Personally I would not use them, but that is because I am easily distracted, and could leave some charging while unwatched which is a big no no. From what I have been told here, they are quite safe if treated with respect i.e. watch them while charging. I'm not sure if there is any danger in actual use.

 

[45/70]

......From what I have been told here, they are quite safe if treated with respect i.e. watch them while charging. I'm not sure if there is any danger in actual use.

This is pretty much the bottom line. Li-Ion cells are safe, when maintained properly. In my opinion, they are far safer than the CR123A lithium primary chemistry (a lithium chemistry that differs from the AA, AAA versions). In fact, there are far more incidents from the misuse of CR123A primary cells on these Forums, than incidents involving Li-Ion cells.

As far as Li-Ions being dangerous while installed in your flashlight/torch, it's the CR123A primaries that have a high rate, not Li-Ion's. It's extremely rare for Li-Ion cell's to cause any problem, when in use. As you pointed out, the potential danger using Li-Ion cells, is when charging. And, as you also pointed out, following proper charging procedures eliminates this problem. It's this last part that many newcomers to Li-Ion cell use, just don't seem to understand. It's no wonder, the way web dealers promote them like candy, without any hint as to how they should be used and maintained. Therein, lies the problem, and where we, the members of CPF, have a calling.

Dave

 

[Magic Matt]

Well I don't know about elsewhere in the world, but in the UK it's very hard to get unprotected Li-Ion cells (unless you go to a specialist). Protected Li-Ion cells can be bought from high street stores with a charger, but I've only seen them seperately once.

Dave: "In fact, there are far more incidents from the misuse of CR123A primary cells on these Forums, than incidents involving Li-Ion cells."
My opinion is that this is probably because having read the forums, people are much more careful with their Li-Ion cells. Outside of these forums, I suspect there are quite a few Li-Ion stories, because people don't understand the risks.

I include myself in that group - there's no way I'd use Li-Ion cells in my own projects until it had been thoroughly tested on the bench with a suitable power supply to check it cuts out at the right voltage and doesn't draw too much current. Before I started reading the info on these forums, I would have probably chanced it and had a story of my own.

I think CR123 primaries should be protected cells too.

 

[LeifUK]

CR123a are widely used in consumer products, far more so than specialist LiIon cells such as the 18650. So you can't compare directly the number of problem reports unless you know the total number of cells in use. My macro flash system uses two, one per flash unit. I also have other non torch (flashlight) products that are powered from CR123a units.

I think CR123 primaries should be protected cells too.

Isn't the protection to prevent overcharging? In which case it is not needed, unless I am mistaken.

 

[45/70]

I'm with you Matt, and agree that the knowledge obtainable here is hopefully why incidents are less common with Li-Ion cells.

I would like to point out that the protection circuitry that is added to "bare" Li-Ion cells, is there to prevent potential problems when the cell is recharged, not to prevent anything from happening when the cell is over discharged. You can run a Li-Ion cell totally flat, and nothing will happen. It's when you go to charge a cell that has been discharged to an unsafe level, that the fireworks will occur.

It is my understanding that even in series applications, where reverse charging occurs when the "pack" is run to a low level of charge, where one cell becomes depleted before others in the "pack", and is exposed to current running the opposite direction through the cell, that Li-Ions are more tolerant than lithium primaries in this regard. With primary cells, you're pretty much guaranteed fireworks, whereas with Li-Ion cells, as I understand it, it is unlikely to be eventful.

Now, if you go to charge a Li-Ion cell that has been reverse charged (or discharged to too low a level), then you have a problem. Once again, most dangerous situations involving Li-Ion cells, are when charging them, not using them.

Dave

 

[march.brown]

.
Five of my torches use 18650 batteries ... Three of these will also use three AAAs in a cassette arrangement ... I now have a Digital Multimeter which I use for voltage measurements plus my old analogue Avo 8 which is used for current measurements ... I feel better equipped to monitor the state of charge on the 18650s as the percentage capacity is directly related to the open circuit cell voltage.

I have two Ultrafire Unprotected and at the moment two Ultrafire Protected cells ... I have four more Protected ones coming in the post ... All these torches only use one 18650 each ... I understand that possible danger could arise if the torches used multiple cells where one cell was undercharged when used with fully chaged cell(s) ...I am now therefore perfectly happy when using 18650s in a single cell torch ... If I exercise a modicum of care, I can see no problem with using unprotected 18650s in a single cell torch.

You can halt the charge whenever you want and after a few minutes resting, measure the cells open circuit voltage ... This will give an indication of the percetage capacity that has been reached ... If the voltage is below the 4.2 Volt threshold you can simply put the cell back on charge and check again later ... This is no problem as the cells do not have a memory ... When the cell has measured 4.2 Volts after resting, you can assume that it is fairly near to the 100% capacity ... If I feel the urge to monitor further, I can use the Avo 8 in series with the cell to watch the charge current reduce to just a few milliamps.

So, I am much happier now than when I first read about this type of cell chemistry.

I will be sticking with 18650s for the (slightly) bigger carry torches and AA and AAA for the others ... I can see no benefit in using the 123 series of cells ... A single slim and shortish single AA torch is in my eyes much nicer than a short fat dumpy 123 torch ... Beauty is in the eyes of the beholder.
.

 

[45/70]

.
So, I am much happier now than when I first read about this type of cell chemistry.

That's good to hear, march. :thumbsup:

Knowledge is wisdom, wisdom is ....... eh, I forget, but anyway.

Dave

 

[Darell]

People need to take some personal responsibilty over the products they are using. You can't legislate for stupidity

Ahh! I wanted to be the first one to answer something like this! Well said. If we took away everything that anybody found "dangerous" I'd rather just crawl into a dark cave and die. In all honest, it amazes me that we can legally pump gasoline into our vehicles, drive around thousands of other vehicles with tanks of the stuff (at high-speed, no less!) and then park tanks of this stuff in our attached garages. And we don't even give it a second thought. But boy... if a battery catches on fire, watch out!

 

[digitor]

Well I don't know about elsewhere in the world, but in the UK it's very hard to get unprotected Li-Ion cells

Actually, unprotected cells are readily available in the UK (and elsewhere) - in the form of lithium ion polymer batteries which are used for RC models. Multi-cell configurations have balance leads, but not all chargers (such as the Swallow) have in-built balance capability.

LiPos are probably one of the more unstable forms of Li-Ion cells, and also they are easily physically damaged which can start a fire - I've seen some interesting pics of burnt out planes!

Cheers

 

[Illum]

unprotected lithium batteries are not dangerous if used properly, it was not until recently that the industry standard of "safe" regards using them in flashlights

 

[roadie]

anyway, dun forget that some people will buy the unprotected cells to build their own lion battery pack ( like me ).

further adding a protecting circuit to the pack upon completion.

thus, with the initial circuit on the cell, means lesser work.

 

[Vikas Sontakke]

Ahh! I wanted to be the first one to answer something like this! Well said. If we took away everything that anybody found "dangerous" I'd rather just crawl into a dark cave and die. In all honest, it amazes me that we can legally pump gasoline into our vehicles, drive around thousands of other vehicles with tanks of the stuff (at high-speed, no less!) and then park tanks of this stuff in our attached garages. And we don't even give it a second thought. But boy... if a battery catches on fire, watch out!

Wow! I have not seen you on CPF for years!!

- Vikas

 

[Vesper]

Car are dangerous.

Mountain bikes are dangerous.

Matches are dangerous.

Fireworks are dangerous.

Angle grinders are dangerous.

But yet they are all still on sale.

BUT they are all only dangerous if they are improperly used - the same applies to 18650's - if they are used properly they are almost perfectly safe - if misused then they are going to bite you in the ***.

People need to take some personal responsibilty over the products they are using. You can't legislate for stupidity - think of it as natural selection.

Amen brother. Well said.

 

[Lightcrazycanuck]

Amen brother. Well said.

+1


lovecpf