18650 - Are protected batteries ALWAYS better?

[recDNA]

With so many users now proclaiming unprotected batteries are not only as good as protected batteries but somehow better or even safer it is refreshing to read a post like yours.

For all but the most experienced and safety conscious users I agree protected cells are best.

 

[SG Hall]

To get back to the OP title, the answer still has to be no. Even a flashlight novice such as me knows the dangers of ICR chemistry over IMR, the dangers of shorting an ICR with no protection, and of over discharge. They are clearly not safer without the protection cell and this has to be factored in. But the answer is still no. In a high drain device an unprotected cell is better unless we bought it to look at. 🤔

We go hunting, ride motorbikes and play sport and we ( most of us anyway!) avert risk where possible and still participate. And we use unprotected cells in our quality high drain lights to get extra performance. It is no different in my view.

 

[space-cowboy]

To get back to the OP title, the answer still has to be no. Even a flashlight novice such as me knows the dangers of ICR chemistry over IMR, the dangers of shorting an ICR with no protection, and of over discharge. They are clearly not safer without the protection cell and this has to be factored in. But the answer is still no. In a high drain device an unprotected cell is better unless we bought it to look at. 🤔

We go hunting, ride motorbikes and play sport and we ( most of us anyway!) avert risk where possible and still participate. And we use unprotected cells in our quality high drain lights to get extra performance. It is no different in my view.

What is difference: unprotected ICR vs unprotected IMR ?

Please explain

 

[Dr. Mario]

ICR = Lithium Cobalt Oxide cell and IMR = Lithium Magnesium Dioxide cell. IMR cells have higher runaway temperature point than ICR cells - the reason why ICR cells run away rapidly at 90 Celsius (194 Fahrenheit) is because of Cobalt Oxide, and Cobalt easily let go of Oxygen at that temperature (since it has incredibly weak Oxygen bond), and all that adds Oxygen to the fuel (in this case, incredibly flammable Ester-based - or any Ether compounds - electrolytes which has lower flash point than Gasoline - 180 to 250 Fahrenheit is enough to ignite it). Magnesium has somewhat better grip at Oxygen so the IMR battery is unlikely to run away unless it gets past 240 - 270 Celsius (464 to 518 Fahrenheit), which means it / they won't vent with flame since Magnesium wouldn't let go of Oxygen if the venting battery didn't hit 460 - 520 Fahrenheit. IMR cells are also internally constructed to take a lot of electrical abuses (although not as good as Lithium Iron Phosphate cells), making it attractive for usage in the vapers and powerful flashlights.

 

[HKJ]

ICR cells run away rapidly at 90 Celsius (194 Fahrenheit)

That is way to low, it is in the 150C (Venting) to 210C (Thermal runaway) range.
http://pubs.rsc.org/en/content/articlehtml/2013/ra/c3ra45748f

If the runaway was at 90C I would have seen many runaway during my testing, but I have never seen one.

 

[StorminMatt]

Also, keep in mind that there are not a whole lot of pure ICR cells sold anymore. Most high capacity cells these days are hybrid IMR/INR cells, which are significantly safer than pure ICR cells.

 

[Dr. Mario]

That is way to low, it is in the 150C (Venting) to 210C (Thermal runaway) range.
http://pubs.rsc.org/en/content/articlehtml/2013/ra/c3ra45748f

If the runaway was at 90C I would have seen many runaway during my testing, but I have never seen one.

Good point, I stand corrected. Older ones will, though (which was why Sony had to up their safety research department a few decades ago).

StorminMatt - that's a good thing pure ICR cells are going the way of dinosaurs because it's somewhat easy to mishandle those cells, and I'd rather using safer variant of Lithium-ion cells.

 

[recDNA]

Ya, unfortunately except for old cells you cannot buy pure IMR chemistry cells assuming you ever could. Most cells today are hybrid, maybe all. This means we have no real idea at what temperature they will burst into flame. There are now protected cells that give us 10 amps without tripping. That is enough for a flashlight.

Zebralight now insists on unprotected cells. I'll stick with the older models.

 

[StorminMatt]

Zebralight now insists on unprotected cells. I'll stick with the older models.

Then again, how is a protection circuit mounted on a battery REALLY better than one in a light? In fact, I would rather have protection in a light than on a battery (where it will get banged around, dropped, and where it often has a strip down the side that can potentially be a dead short). I just don't see how an onboard protection circuit is BETTER than using good cells, using good chargers, and storing batteries in plastic cases so they can't short.

 

[recDNA]

Better to have both. I like protected batteries for charging too

 

[Dr. Mario]

I just go with unprotected cells, less headaches in term of strange behaviors in protection board, and fitment. I do follow very strict battery handling rules, so I ought be good to go, with the unprotected cells.

For the newbies, I'd recommend to go with protected cells, even the LiFePO4 cells, just so they don't cause damage when one makes a mistake.

 

[magellan]

A123 Systems LiFePO4 18650s can provide a continuous 33A. Admittedly, though, with only 1100mAH of capacity, they won't do this for long.

As for the original question of protected vs unprotected batteries, I myself have never used protected batteries. Even in lights with series cells. Unprotected batteries are cheaper, smaller (especially shorter), and produce a higher voltage. People worry about safety. But if you use quality cells, quality chargers, store them in plastic cases, and use them in single cell lights with built-in overdischarge protection, there is absolutely NO safety disadvantage to using unprotected cells. In lights without overdischarge protection, safe use of unprotected cells is mainly a matter of knowing how long your light will run on a full charge and keeping it charged. Also, recognizing when your light starts to dim is VERY helpful in knowing when it is time to change batteries. With multi-cell lights, it's all about knowing your runtime. Low battery warnings can also help, especially if you use good quality cells that track voltage evenly from one cell to another.

Great summary of the issues from you and Ven. That's kinda how I look at although I do have maybe 20% of my 40 or so 18650 batteries in protected versions with various brands.

 

[recDNA]

I have both but I prefer to use protected batteries if they fit. I'm always torn between unattended charging on a concrete garage floor and me watching charging on a porcelain plate on a wooden coffee table. I charge indoors where I can watch but find it stressful. I prefer to use primaries when possible because I hate charging so much. Never had a problem charging. Just aware.

 

[StorminMatt]

I have both but I prefer to use protected batteries if they fit. I'm always torn between unattended charging on a concrete garage floor and me watching charging on a porcelain plate on a wooden coffee table. I charge indoors where I can watch but find it stressful. I prefer to use primaries when possible because I hate charging so much. Never had a problem charging. Just aware.

Here's the thing. There is NOTHING magical about a protection circuit that is going to keep a battery from going 'boom'. It can help prevent a battery from becoming overcharged, undercharged, or overdrawn. But the battery will do what it wants to do - protected or not. And when it comes to charging, what REALLY matters is the quality of your charger. A good charger will consistently cut off the charge very close to the proper voltage (4.2V for normal Li-Ion). Even charging your batteries somewhat over this (say, 4.3V) is not going to result in disaster. So I certainly wouldn't take things quite as far as ALWAYS charging on concrete or watching batteries like a hawk if you use good batteries and chargers. You probably don't want to put your batteries on the charger and go off to work. But if you are in the other room watching TV, you should be fine. Because a good charger will safely charge your batteries, protected or not.

 

[recDNA]

A protection circuit can help prevent thermal runaway but not venting. It can also shut off in a short circuit and prevent overcharging. I have very well reviewed chargers but all electronics can and do go wrong sometimes. A protection circuit adds an extra layer of protection. You will not convince me otherwise. Do you think protection circuits designed by Sanyo are jokes? Fake? Don't bother replying. We will never agree on this issue.

 

[StorminMatt]

A protection circuit can help prevent thermal runaway but not venting.

A protection circuit only helps to prevent conditions that can lead to thermal runaway. It can't actually prevent thermal runaway from occurring.

 

[vadimax]

I have both but I prefer to use protected batteries if they fit. I'm always torn between unattended charging on a concrete garage floor and me watching charging on a porcelain plate on a wooden coffee table. I charge indoors where I can watch but find it stressful. I prefer to use primaries when possible because I hate charging so much. Never had a problem charging. Just aware.

Funny person you are Somehow you manage to suffer flashaholism and batteryphobia at once

 

[recDNA]

Maybe take a look at the sticky battery fire thread. It isn't phobia. It is rational caution.

 

[Connor]

Fires/explosions are super rare in relation to the millions and millions of sold battery cells. And even less common on proper brand cells.

Only unprotected cells and good chargers for me. And voltage-aware flashlights.

 

[markr6]

Fires/explosions are super rare in relation to the millions and millions of sold battery cells. And even less common on proper brand cells.

Only unprotected cells and good chargers for me. And voltage-aware flashlights.

Well put. Same here.