Why Use Unprotected While Protected Works Fine?

[psychbeat]

I've had two AW protected 2600 short on me (scary).
One form being dropped and the other from a snag in a battery carrier.
In some instances I've concluded that protected can be more dangerous with that thin little flat wire running the length just waiting to short.

Nothing against AW here btw - I use his "IMR" 18350s & 16340s

I've even removed the PCB from the rest of my AW2600s and rewrapped.
They're old but work fine for low drain lights.

I only buy raw name brand cells from trusted vendors now.
GAs & Qs have me covered.

 

[chillinn]

I've had two AW protected 2600 short on me (scary).
One form being dropped and the other from a snag in a battery carrier.
In some instances I've concluded that protected can be more dangerous

This is very interesting. Can you please be more specific? Are you saying the protection strip itself shorted the cell? What, exactly, do you think happened there? Thanks.

 

[markr6]

There are a few reasons why I use unprotected cells:

1. They fit in lights better both in length AND diameter.
2. There is no risk of damage to a light from an excessively long battery from spring pressure and/or binding.
3. They are cheaper. This is particularly true in the case of overpriced flashlight-branded protected cells.
4. You avoid the voltage drop associated with a protection circuit.
5. You have more choices when it comes to cells - generally only a few cells (ie the most popular ones) are available protected.
6. Protection circuits limit maximum current draw - NO truly high current cell can have on-board protection for this reason.
7. There is no risk of short circuit between the negative battery can and positive strip along the side.
8. There is no risk of short circuit from physical damage to a protection circuit (such as from a drop).
9. Some lights can't use protected cells (ie Zebralights).
10. Protected cells can unexpectedly leave you in the dark (unlike protected lights, which step down before cutting out).
11. Cells are generally safer nowadays due to safer chemistries, built-in failsafes, and wider availability of quality cells (and bad cells are easier to avoid).
12. Most quality lights have good low voltage protection.
13. Quality chargers that won't overcharge are inexpensive and widely available.
14. It's really not THAT hard to properly care for unprotected cells and avoid overcharge/overdischarge.
15. You will actually learn to care for your batteries BETTER if you use unprotected cells. FOR REAL!

HAHA "a few". I agree with all this :thumbsup:

 

[psychbeat]

This is very interesting. Can you please be more specific? Are you saying the protection strip itself shorted the cell? What, exactly, do you think happened there? Thanks.

On both occasions the thin flat wire shorted to the metal case. Once, on the edge near the positive end and the other near the neg end when the cell was dropped.

When this happens you need to watch out as the flat wire heats up quickly and will melt the wrapper.
Both of the cells were fine after I removed the PCB and rewrapped. In fact, I'm still using them regularly.

These were genuine cells purchased directly from Andrew's old thread on CPFMP.

 

[psychbeat]

HAHA "a few". I agree with all this :thumbsup:

+2!

 

[peter yetman]

I've had the PCBs fail on a couple of my protected AW cells and removed them to use unprotected. You're right about that wire strip, if it shorts it glows red hot - very scary.
In view of the PCB issue and the fact that the light just extinguishes when the circuit trips in, I'm going to buy unprotected from now on. I've played with LI-Ions for a few years now and know how to treat them with respect thanks to this Forum.
But I would still recommend protected cells to new users.
P

 

[Dr. Mario]

I personally use unprotected Lithium-ion batteries mainly from the point of view on usage risks; as I have firmware-defined LED flashlights (eg, those using Nanjg AK-47A with ATTINY microcontroller in use), so battery discharge limits aren't the biggest concern as the software on all of my DIY flashlights cut out at 2.8 - 3 Volts (although I will have to raise the cutout voltage on a few flashlights for a few special INR 18650 cells such as LG MJ1 which is best cut off at 3.5 Volts for lifespan reasons).

Protected cells work just fine for my usage, however, as the others pointed out, is that there is concerns with the Anode strip which can chop through the Kapton tape (yellowish tape which can resist some serious heat), causing short-circuit which the 18650 cells can dump up to 60 Amps of current into, heating up the cell significantly, possibly initiating the thermal runaway - I prefer to use the protected cell with the original wrapper intact as they usually offer better protection than the Kapton tape, but you never know, especially with most circuit breaker board's components exposed in the cell spacer (the bottom plastic piece at (-) end of cell, holding the circuit breaker board), as it's the most vulnerable spot. I prefer to use it in the flashlights I don't expect to drop. For that flashlight, unprotected Lithium-ion batteries is used instead as circuit breaker function is to be handled by the firmware on the LED driver.

 

[peter yetman]

Nice explanation, Doc.
P

 

[Lou Minescence]

After reading the posts here I ask someone to change the title of this thread
" Why Use Protected While Unprotected Works Fine ?
[emoji3]
I use both types of batteries but prefer to use protected where possible. I have about 60 lights and it is getting to be a hassle trying to remember what light can and can't take which battery.
The 5 years ago battery threads were all about how crazy it was to use non protected batteries. Times have changed. I do like the fact non protected batteries are cheaper than protected. If you suspect a problem get rid of the $6 non protected battery. When the protected battery costs $15 I think a little harder about disposing of it.

 

[ven]

I only use protected cells if i need the extra few mm for contact or simply because i still have a few and to use them.................certainly not for the PCB. They still have a place imo, but if they are relied on or cause the user to become complacent thinking the PCB will save them, then again its misguided imo and the chemistry protected or not is not for them.

Education and common sense(ironically which is not that common) are key, after all you can have all the protection you want in a car, air bags, abs, active this,that and the other..............they still crash and thats after lessens,courses etc. Joe public can go buy these cells with no knowledge, stick them in a device and use till flat. Slap them on a *****fire charger overnight, forget about them till they get in from work. They dont know their fake 4000mah cell is not 4.6v, they then stick it in ther $5 light and probably get away with it for weeks, months..............then! People will still chuck an 18650 in their pocket/bag with lots of keys and other metal objects next year, and the year after. Again they will probably get away with it for weeks..........heck maybe years till...........!

You buy a sharp knife, you know it can chop your fingers off, but people still do................human nature i guess.

Our motto is all accidents are preventable, which is true, yet we still stub our toes and bump our heads. Education, warnings and CPF is the answer to reduce incidents.

As above, cells are cheap, if unsure, or over discharged and left for an unknown period, recycle................easy as that. No one is perfect, but we learn from our mistakes(hopefully), many dont who seem to appear on the news and most of that i would put down to education/ignorance.

imo, not saying i am right in anyway, just my thoughts. Today, with cell chemistry and driver tec, things are very different than 5yrs+ back.

 

[TinderBox (UK)]

I only use protected cells in flashlights that take more than 1 li-ion cells to protect me against out of balance cells.

Protected cells in flashlights can leave you in the dark when the low voltage protection kicks in, not something you want to happen in an emergency.

John.

 

[Thom2022]

As someone who's been vaping on mech mods for years I only have unprotected cells for use when my flashlight finally turns up. They are fine to use in series will a little common sense. Only use married pairs and label them A and B and after ever charge switch their position in the light so the load is shared equally over time. I keep a log book next to my charger that has voltage after use, voltage after charge, total charge time and last position in the battery sled. Yes it takes up a bit of time but there's no substitute for safety.

 

[Dr. Mario]

Of course, protected Lithium-ion batteries do still have their place, especially in the multi-celled flashlight which you do need a lot of redundancy to ensure it stay safe - most circuit breakers trip if there is inconsistency in current consumption.

On the other hands, they're kind of useless in the pocket rockets except for low power mode which they're still okay for use in a pinch. Most low drain protected 18650 cells trip out at 2 - 5 Amps which is not good enough for usage in the triple LED pocket rockets.

And yup, common sense still applies. I'd recommend to buy a cheap DMM (digital multimeter) to check the battery voltage to judge whether it has enough juice or not, and to be sure multiple 18650 cells are within 1 - 10% of each other if you chuck them all in multi-celled flashlight, and it's also therefore much more strict when you use them in vapers (since they're more abusive than flashlight from current consumption standpoint - not all vapers are created equal, however, a few vapers use DC-DC buck converter which usually mean less current demand on batteries depending on wattage settings).

And no Ultrafire batteries. Genuine XTAR chargers (and a few other respectable brands) can be had from the cigar shops and Amazon websites - you have to confirm if it's genuine though as it's easier to get the fakes nowadays. Genuine chargers and genuine batteries are every flashoholic's best friends.

 

[chillinn]

Of course, protected Lithium-ion batteries do still have their place, especially in the multi-celled flashlight which you do need a lot of redundancy to ensure it stay safe - most circuit breakers trip if there is inconsistency in current consumption.

Only just within the last few days I have been introduced to the idea that the protection strip can fail, at times spectacularly, for whatever reason. Safety redundancy appears on its face to benefit all. But if you consider that the more complexity you add to something, the more points of failure exist, the necessity of safety redundancy is diminished.

I'm not disagreeing just to disagree, but hopefully in dissent we all might better have an overall view of the facts and the truth (which is philosophically (i.e. epistemologically and metaphysically) unknowable, unattainable... we can only reduce the margin of error) , and then better base our own conclusions on what is necessary or ideal for our individual purposes.

 

[seery]

A few months ago we switched to all unprotected cells (GA/VTC6/30Q) in our K60's and K70's.

Nothing more than I just feel more confident in them vs. the protected KeepPowers and Evva's we had been using.

 

[Dr. Mario]

Only just within the last few days I have been introduced to the idea that the protection strip can fail, at times spectacularly, for whatever reason. Safety redundancy appears on its face to benefit all. But if you consider that the more complexity you add to something, the more points of failure exist, the necessity of safety redundancy is diminished.

I totally agree.

That's why I prefer to use unprotected Lithium-ion batteries nowadays as the low voltage cutout circuit breaker function is adequately provided by the software nowadays on 7135 LDO or buck / boost converter LED drivers which are now managed by the microcontroller chips.

Low voltage cutout in the provided circuit breaker board inside the protected Lithium-ion batteries are considered the last resort (which is to cut off at 2.5 Volts) which shouldn't be abused unless you can confirm it cuts off at 3.0 - 3.5 Volts. As for amperage rating on the cell, the purpose of high drain cell is effectively defeated by the circuit breaker board which usually trip way below what the cell is capable of.

So it's a no-go on the pocket rocket flashlights which may drain way above the cutoff current settings (usually at the current rating significant enough to obliterate the SMD components in the circuit breaker board - about 10 Amps or more, from the trends of the pocket rockets discussed hereon).

Hence, for the TLR version: Not worth using protected Lithium-ion batteries in intelligent LED flashlight which usually has low voltage cutout protection and in the pocket rockets.

P.S. We now need to include multi-voltage, multi-cell circuit breaker function into the multi-celled flashlight as there is enough space on the LED driver board, and potentially enough space on the microcontroller chip's flash memory. That way we can eliminate a few remaining problems with the sketchy protected Lithium-ion batteries.

 

[vicv]

I totally agree.

That's why I prefer to use unprotected Lithium-ion batteries nowadays as the low voltage cutout circuit breaker function is adequately provided by the software nowadays on 7135 LDO or buck / boost converter LED drivers which are now managed by the microcontroller chips.

Low voltage cutout in the provided circuit breaker board inside the protected Lithium-ion batteries are considered the last resort (which is to cut off at 2.5 Volts) which shouldn't be abused unless you can confirm it cuts off at 3.0 - 3.5 Volts. As for amperage rating on the cell, the purpose of high drain cell is effectively defeated by the circuit breaker board which usually trip way below what the cell is capable of.

So it's a no-go on the pocket rocket flashlights which may drain way above the cutoff current settings (usually at the current rating significant enough to obliterate the SMD components in the circuit breaker board - about 10 Amps or more, from the trends of the pocket rockets discussed hereon).

Hence, for the TLR version: Not worth using protected Lithium-ion batteries in intelligent LED flashlight which usually has low voltage cutout protection and in the pocket rockets.

P.S. We now need to include multi-voltage, multi-cell circuit breaker function into the multi-celled flashlight as there is enough space on the LED driver board, and potentially enough space on the microcontroller chip's flash memory. That way we can eliminate a few remaining problems with the sketchy protected Lithium-ion batteries.

How is the driver going to know individual cell voltages without it being a proprietary pack? You need wires going to each individual cell in that case. Not possible in a tubular flashlight

 

[Dr. Mario]

It don't have to. The trick is using voltage dividers feeding into the microcontroller ADC (analog to digital converter) and work with the cell voltage values from both ADC and settings in the software. It's usually what some cheap LED drivers like Nanjg do to ensure it don't go out of check.

As for multi-celled circuit breaker, there's no need for proprietary battery either, you just read individual cell's voltage and make a decision to continue or either cut off or dim down and flash a warning strobe (red LED in the button) to indicate the problem with batteries, while also buying you a bit time with dim light so you can swap out the batteries after finding alternative sources of illumination.

Microcontrollers nowadays have several on-die ADCs which is useful in several type of sensor applications - you can also substitute that with a Lithium-ion battery protection chip and latch onto its I2C / SPI bus to figure out what's going on. That's the beauty of software, it allows you to do that cheaply (even to the point it make some proprietary chips totally unnecessary).

As for tubular flashlight (can style), there is usually room for several wires. There's no excuse in that because of the volatile nature of the Lithium-ion batteries - it's best to continuously monitor the cells to be sure, as I don't think some folks would ever bother to check any cells before chucking them in. It's either the flashlight shutting down safely or it explode taking its user with it. It's also further proven by rashes of news concerning exploding multi-celled vapers.

 

[vicv]

But how are you going to load cells into a flashlight from either the tail or the head when there's a tab or something in between the cells? Load one cell from each end? That's rather inconvenient. I like your idea. Like lipo packs where there's a balance cable. That's a premade multi cell pack though. Implementing that idea into a tubular flashlight that takes cylindrical user replaceable cells just isn't feasible. Also cells going out of balance are not going to explode. If there's that much of an imbalance to really cause problems the lower capacity cell will just be dead. And the charger will not charge it if it's too low or if the polarity has been reversed

 

[Dr. Mario]

Spring-loaded pins for voltage measurement taps and retainer pins on the printed circuit board on the battery carrier so it don't rotate when you twist the cap back in. If you have seen the soda can style quad-celled flashlight, you would know what I mean - some has battery carrier.

I would do this on my soda can flashlight (with a custom LED driver board) because I simply can't trust that the batteries won't go out of balance - it's like building a house without the foundation and expecting it not to fall apart.