Battery question: 18650 + 123.

[Curias]

I'm about to buy a bored 9P (+ Malkoff M61x) and was wondering about putting a 18650 and a cr123 in at the same time.

Aside from sounding weird, would there be any negative aspects to this, like one being a weak link, or the 18650 running out well before the 123.

Would I get a worthwhile jump in runtime over just a single 18650 in a 6P?

I know many might suggest going with 2x18500, but I'd like to stick to 18650s and primaries.

 

[jasonck08]

Very dangerious. Do not mix different types / capacities of cells.

Stick with a bored 6P, or use 2x18500 in that light.

 

[45/70]

No, never do that!

As Jason said, don't ever mix different chemistry, size, or capacity cells, especially with lithium, and/or lithium ion cells.

Also, provided the 18650 was fully charged, it would likely out last the CR123, and while the CR123 is smaller, it's chemical composition is at least twice as volatile as a Li-Ion. In either event, you're setting the stage for an explosion mixing those cells, if either one were to be reverse charged.

Don't do it!

Dave

 

[TranceAddict]

dont do that !

 

[LuxLuthor]

I'm about to buy a bored 9P (+ Malkoff M61x) and was wondering about putting a 18650 and a cr123 in at the same time.

Aside from sounding weird, would there be any negative aspects to this, like one being a weak link, or the 18650 running out well before the 123.

Would I get a worthwhile jump in runtime over just a single 18650 in a 6P?

I know many might suggest going with 2x18500, but I'd like to stick to 18650s and primaries.

I was hoping you weren't asking what this subject title indicated you might be.

On the one hand, it is important for people to see this question and how much is still not known about proper, safe Lithium battery usage, so I commend you for asking first. There are likely others who had the same question. :thumbsup:

In a nutshell, this would be an utter disaster waiting to happen, and I hope many others learn from it, and what sort of things can go wrong with the Lithium chemistry that they may not be aware of.

• Never mix Lithium cells of different brands (i.e. Surefire 123A + Energizer 123A; or AW 18650 ICR + Eagletac 18650 ICR).

• Never mix Lithium cells of same brand, but different mAh size (i.e. AW 18650 ICR + AW 17650 ICR)

• Never mix Lithium cells of different voltage states (even if from the same brand & type) (i.e. new Surefire 123A + used Surefire 123A; or fully charged AW 18650 ICR + medium charged AW 18650 ICR)

• Never mix different Lithium chemistries (i.e. Lithium Cobalt "ICR" + Lithium Manganese "IMR").

• Never Never Never mix rechargeable with primary Lithium cells. Never. (i.e. AW 18650 ICR + Surefire 123A)

 

[Curias]

Ok, thanks guys. I'm glad I asked. I am kind of surprised I hadn't heard anything about this yet, after reading these forums so much, but I guess it's common knowledge around here, and goes without saying.

 

[LuxLuthor]

No, it's not common knowledge. It only becomes knowledge if someone goes looking, or asks a good question like you did. You made a real contribution, as others will see this now. I really appreciate that you made this thread.

 

[novice]

This may be a little off-topic, but regarding not using lithium rechargeables with different voltages, can anyone give some guidelines as to what minor differences might be acceptable, or does a pair have to match EXACTLY?

For instance, I just got into rechargeable lithiums (mainly for my A2), and got some blue label tenergy RCR123a's, and the Tenergy charger that is matched with them (the charger is small, and I am little worried about it). I charged two different pairs, and they came off the charger with matching voltages, according to my $5 harbor freight DMM.

The third pair had some differences when they came off of the charger (can't remember how much), so I charged the 'low' one separately, overshot the other one, then did the same process to the other one. The charger doesn't seem to terminate very well(?). I know that 'regular' RCR123a's usually max out at 4.2v, but aren't these '3v' Tenergy supposed to stop at 3.7v? The first pair were 3.85v each when I pulled them off, and the second pair were 3.87v each when I pulled them off, but my 'separate' charging attempts for the third pair have them both in the ~3.9v range, which worries me (I can't remember the exact figures right now). My plan at this point is to use each of the 'mismatched' cells of the third pair separately in a 3P clone with a Malkoff M30, to bleed them both down separately down around 3.8vish something, so they both match in voltage, before I use them together.

My 2 questions are:

1 - Is a difference of .01, or .02, or .0x volts acceptable in a pair of lithium rechargeables? Is it critical that they are absolutely IDENTICAL in voltage?

2 - Does a voltage of 3.8ish, or 3.9ish, sound normal for a Tenergy blue label '3.0' volt lithium rechargeable? Do I need to monitor the charging process more closely to make sure that they don't get above (fill-in-the-blank)? These are 'protected' cells, but I am new enough at this that I don't know what the proper figures should be, and the Tenergy packaging doesn't help out at all.

Thank you for your assistance.

 

[donn_]

• Never mix Lithium cells of different brands (i.e. Surefire 123A + Energizer 123A; or AW 18650 ICR + Eagletac 18650 ICR..).

I never heard this one, and I've done it hundreds of times, with no ill effects.

 

[LuxLuthor]

I never heard this one, and I've done it hundreds of times, with no ill effects.

Good, then I'm glad I posted it, and I stand by it. Many of these guidelines will be violated by various people...until something goes wrong and we hear about it. That you have not had ill effects means you have been fortunate. They all have different characteristics, different internal resistances, different current outputs and behaviors. Mixing should NEVER be done.

 

[donn_]

Another non-sleeper. Glad to see I'm not alone in this affliction.

 

[LuxLuthor]

Another non-sleeper. Glad to see I'm not alone in this affliction.

It happily coincides with Flashaholism.

Donn, to provide you with one of many specific references to my warning, see item #10 on p. 13 of this 14 page Samsung 18650-ICR PDF.

 

[MorePower]

• Never mix Lithium cells of different brands (i.e. Surefire 123A + Energizer 123A; or AW 18650 ICR + Eagletac 18650 ICR).

Mixing brands of any US made CR123A cells (surefire, duracell, energizer, rayovac, battery station) really shouldn't be a problem. The differences between them are so minor as to fit within statistical variation.

Rechargeable lithium ion cells, on the other hand, tend to show much larger brand to brand differences and therefore have much greater potential for issues.

 

[ASheep]

Good thing the OP asked this question, I think there are a few people floating around wondering the same thing. Good warnings LuxLuthor, well said. Some people don't realise how dangerous Lithium Cells can be. When you have that much energy stored in a small volume, it will do some damage if it is released quickly.

I have seen some dealers (who shall not be named here), who are advertising the ability to use "1x CR123A and 1x 18650" in certain Romisen flashlights, as an alternative to 3x CR123A. This is downright dangerous, especially in a high drain light.

 

[LuxLuthor]

Mixing brands of any US made CR123A cells (surefire, duracell, energizer, rayovac, battery station) really shouldn't be a problem. The differences between them are so minor as to fit within statistical variation.

Rechargeable lithium ion cells, on the other hand, tend to show much larger brand to brand differences and therefore have much greater potential for issues.

The problem with your qualification is that very few people using CR123A cells are certain which cells were all made in the same factory. I don't think you will find any retailer, manufacturer, or spec sheet that will back up your statement...even though I know where you are coming from.

I also think you should consider the implications of your advice for people still holding onto older non-USA made Battery Station (and other brand) cells, not having heard about problems with them.

Most people will hear your very specific branded & qualified statement and extrapolate that it is OK to mix any kind of 123a cell. Then there is the complication of mixing various secondary Lithium brands.

 

[lctorana]

This scenario will almost guarantee a vent-with-flame scenario.

Why am I posting this, when others have already said so?

Because I have found the link:

http://candlepowerforums.com/vb/showthread.php?p=1497172

Read the whole of post #1, and in particular, please watch the videos at the bottom of post #1.

Basically, once the condition of reverse-charging an exhausted primary CR123 cell (such as via a lamp from a fresher cell) is established, then vent-with-flame WILL happen.

That's why we must always have all primary cells at the same state of charge if used together.

 

[LED_Thrift]

My 2 questions are:

1 - Is a difference of .01, or .02, or .0x volts acceptable in a pair of lithium rechargeables? Is it critical that they are absolutely IDENTICAL in voltage?

2 - Does a voltage of 3.8ish, or 3.9ish, sound normal for a Tenergy blue label '3.0' volt lithium rechargeable? Do I need to monitor the charging process more closely to make sure that they don't get above (fill-in-the-blank)? These are 'protected' cells, but I am new enough at this that I don't know what the proper figures should be, and the Tenergy packaging doesn't help out at all.

Thank you for your assistance.

1 - A small voltage difference is acceptable. It's hard for me to put a number on it, but I would say that up to 0.1 is fine as long as you are not driving the cells extremly hard. Most production LED lights won't drive cells to a critical level. The most dangerous time for most cells is when they are drained, if the cells are 'protected' there is an additional safety net, although for best cell life & performance they should be charged before the protection circuit kicks in.
2 - Those cells have a circuit in them that drops the voltage to 3.0v when the cell is under load. A cell being tested [with no load] will show a voltage in that range.

 

[ASheep]

Because I have found the link:

http://candlepowerforums.com/vb/showthread.php?p=1497172

Read the whole of post #1, and in particular, please watch the videos at the bottom of post #1.

Basically, once the condition of reverse-charging an exhausted primary CR123 cell (such as via a lamp from a fresher cell) is established, then vent-with-flame WILL happen.

That's why we must always have all primary cells at the same state of charge if used together.

I knew I wasn't crazy for obsessively testing the cells in my Surefire A2 before prolonged use. It's the only multi lithium cell light I have, and every time I'm going to use the incan lamp for more than a couple of seconds, I test the batteries with my multimeter and a small resistor, to give them some load.
I also obsessively test my 18650s, as they are unprotected sanyo cells harvested from a laptop battery pack. They get a visual inspection of the wrapper for splits, and a voltage test before being put into a light, and I only use them in single cell configurations.

Those explosion videos in newbie's thread really drive the point home. The high energy density of lithium cells can be dangerous, especially when contained in a pressure vessel.

Edit: Wow my 100th post already

 

[novice]

Thank you, LED Thrift!

 

[LuxLuthor]

Because I have found the link:

http://candlepowerforums.com/vb/showthread.php?t=124776

Read the whole of post #1, and in particular, please watch the videos at the bottom of post #1.

Basically, once the condition of reverse-charging an exhausted primary CR123 cell (such as via a lamp from a fresher cell) is established, then vent-with-flame WILL happen.

That's why we must always have all primary cells at the same state of charge if used together.

Thanks for finding that link. God, I miss Newbie being here. He also reinforces the guideline I gave Donn above on not mixing brands.