How safe are protected Li-Ion batteries?

[linterno]

Have anyone had a venting or explosion with protected Li-Ion batteries?

I have a couple of flashlight that uses CR123A batteries and others that can use 17670, 10440 and 14500. I am also planning to buy other one using 18650, but I don't want to experience any venting or explosion on them. I even bought 12 tenergy CR123A that I am not going to use just to prevent issues.

Now I am planning to buy some Ultrafire/Trustfire 18650, 17670, 10440, 14500 and RCR123A protected batteries. I know AW are the best but also twice to three times more expensive.

This is why I want to know from anyone that have had venting or explosion problems with this king/brand of protected batteries.

I prefer to read about good experiences, but if bad ones have occurred I would also like to know about them.

 

[linterno]

Anyone?

 

[SilverFox]

Hello Linterno,

As long as the protection circuit is working, you should have no problems.

The general rules for safety are to use a charger that doesn't overcharge the cells, use your cells in an application that doesn't draw more than the cells capability to produce, and don't over discharge your cells.

With a good charger, you will never use the protection circuit. The same goes for using the cells under proper loads. Over discharging can be avoided by limiting your normal use to around 80% of the cells capacity. I think the best way to do this is to recharge often and don't run the cells all the way down to the end, unless it is absolutely necessary, like in an emergency.

Also, try to keep from physically damaging your cells.

With proper engineering controls, the protection circuit is just along for the ride and will only come into play when something else fails.

Tom

 

[linterno]

Hello Tom and thank you for your reply,

The general rules for safety are to use a charger that doesn't overcharge the cells, use your cells in an application that doesn't draw more than the cells capability to produce, and don't over discharge your cells.

Shouldn't all this safety rules be handled by the protection circuit?.

Have you ever used Trustfire or Ultrafire protected Li-Ions? if not, What brand have you used without any issues?

Respectfully,

Juan C.

 

[mdocod]

Hello Tom and thank you for your reply,
Shouldn't all this safety rules be handled by the protection circuit?.

Have you ever used Trustfire or Ultrafire protected Li-Ions? if not, What brand have you used without any issues?

Respectfully,

Juan C.

Protection circuits on Li-Ion cells are not designed to kick in for every cycle. Therefor they are set out of normal use "bounds" so to speak. In reality, if you took a protected LiCo02 cell and cycled it bumping up against the protection circuit every single time you discharged it or charged it, the circuit itself would likely wear out sooner, and the cell would develop reduced capacity more rapidly.

Think of the protection circuit as the guy in the sleeper of an over-the-road truck, waking up, and looking up into the cabin to find that the driver has fallen asleep. Jumping to action he slams on the brakes and manages to just barely prevent catastrophe, but that doesn't mean there aren't a few scratches from where the truck brushed up against that guard rail ... Remember, you are the driver when working with loose li-ion cells whether they are protected or not. Don't fall asleep at the wheel.

 

[SilverFox]

Hello Juan,

Yes, it should, however I prefer to use the protection circuit as a back up safety.

I have had problems with cell to cell inconsistency with the Ultrafire, and I believe others have seen the same thing with the Trustfire cells. Some people order a few more cells than they need knowing that some may be bad.

I use Pila, Wolf Eyes, and AW protected cells.

Tom

 

[Lite_me]

Think of the protection circuit as the guy in the sleeper of an over-the-road truck, waking up, and looking up into the cabin to find that the driver has fallen asleep. Jumping to action he slams on the brakes and manages to just barely prevent catastrophe, but that doesn't mean there aren't a few scratches from where the truck brushed up against that guard rail ... Remember, you are the driver when working with loose li-ion cells whether they are protected or not. Don't fall asleep at the wheel.

I love analogies!

 

[Illum]

oo:
in that case my guys in the cells have had all the brake shoes burned off by now

 

[linterno]

Thank you to everyone who have helped me.

Now I understood clearly about how to use this cells with protection circuits. I guess I need to by a good charger (probably a Pila one) and use protected cells.

Juan C.

 

[Hodsta]

Juan,

Chances are you have already seen this but it is the bible for Li Ions and I return to it frequently for reference.

Lithium batteries are so prevalent that it applies equaly the cell phones and laptops as much as for flashlights.

 

[2xTrinity]

So far, based on the number of reported incidents on these boards, Lithium primary cells (CR123) have a FAR worse track record than LiIon cells. The only LiIon venting incidents I've seen involve operator error, attempting to charge a single cell on a multi-cell charger, or somtehing of that sort. I've seen several incidents of CR123s venting inside flashlights during normal operation, however.

Also, your chances of problems go WAY up when using multiple cells, as if they are misbalanced, one can essentially start "charging" the other. This is one reason I'd be wary about using a multi CR123 light. In the case of LiIons, 1x18650 has about double the energy of 2xRCR123, so that's your better option no matter what.

Even in the case of running multiple protected LiIon,s the protection circuit should trip if you end up getting a cell reversal (on cell "charging" another). Again, no such protection exists with primary CR123s.

The case where LiIon cells have problems is genreally during charging -- I know that's when the laptop batteries have vented in most cases -- due to a faulty protection circuitry in a pack fo cells, that continues to charge anyway. If you charge cells individually, rather than in packs, and your cells have individual protection, you should be okay.

 

[Buck91]

Hello Tom and thank you for your reply,
Shouldn't all this safety rules be handled by the protection circuit?.

Have you ever used Trustfire or Ultrafire protected Li-Ions? if not, What brand have you used without any issues?

Respectfully,

Juan C.

I've been rotating a pair of trustfire 14500 protected in my Ultrafire Q5 mod, which pulls just about 1A from any batt, for a couple of months now. Ran into the protection circuit a couple of times when using as a bike light for a bar ride. Charge 'em on a WF-139, no problems so far... Though once hours at work pick back up I want to get some nicer cells. Hopefully they'll hold their voltage better at such a high discharge.

 

[HighLight]

re post #1...I didn't think 10440 protected Li-Ion cells are available?

 

[Illum]

re post #1...I didn't think 10440 protected Li-Ion cells are available?

unfortunately you are correct, they are not protected and no plans to make them protected.

10440 is a pretty small volume to work with. AW reduces the cell size to compensate for the PCB thickness. in the case of a 14500, ultrafire simply use an existing unprotected 14500 and slap a protection on top of it, which adds height to the battery rather unintentionally...making their protected 14500s really ~14530s and this additional length causes contact and fit issues when used in lights or chargers. AW lowers the length of their protected 14500s to exactly 14500 by using unprotected ~14470 cells to compensate for the additional PCB. In the case of the 10440 however, the PCB would have to undergo redesigning and perhaps with two PCB disks to suffice the placement of all the components within a 10mm diameter. If AW was to come out with a protected 10440, the unprotected cell used would be around 44-3-3= ~10280, at severe cost of its already miniscule capacity