Li-Ion purchase upcoming and I need your ADVICE

[Eskimonio]

I have the Maxfire and 6p each with the DX dropin.

There's been much debate over rcr123as not fitting into various flashlights, etc. I'm about to buy some Li-Ions and charger, and don't want to waste $40, nor have the buyer's remorse that comes along with it.

Is there any advantage to using 1 x 18650 battery vs. 2 x rcr123a or vice versa? i.e. longer runtime or brighter light with one setup vs. the other?

Is there any DOWNSIDE to using 1 x 18650 in those lights with that setup?

 

[FlashKat]

Are you sure a 18650 battery will fit inside those flashlights?
If it will fit then I say the 18650 will give you longer runtime. Most of the DX drop-ins are made to work with 3.7v batteries.

I have the Maxfire and 6p each with the DX dropin.

There's been much debate over rcr123as not fitting into various flashlights, etc. I'm about to buy some Li-Ions and charger, and don't want to waste $40, nor have the buyer's remorse that comes along with it.

Is there any advantage to using 1 x 18650 battery vs. 2 x rcr123a or vice versa? i.e. longer runtime or brighter light with one setup vs. the other?

Is there any DOWNSIDE to using 1 x 18650 in those lights with that setup?

 

[AndyTiedye]

If an 18650 won't fit, a 17670 might, but even they are fatter than R123A's.
(And R123A's are fatter than non-rechargeable 123's).

 

[Eskimonio]

Thanks for the replies, but that's exactly what I'm trying to find out, is if an 18650 will fit in the Maxfire AND 6p w/ cree dropin.


My thought process is this: I've heard of 2 x cr123as blowing up in peoples lights, and evidently the quality control (even in AW's batteries some have said) of the rcr123a batteries varies from battery to battery; meaning the diameters and lengths can vary enough to make them not fit in a light properly.

I'm thinking if there's no significant drawback to an 18650 wrt runtime or brightness, that would give the best chance for a fit, and help me avoid the problems associated with 2 x cr123as blowing up.

My whole goal with this post is to make a proper decision, so I don't waste time and money ordering one type of battery, when the other is a better choice.

Thanks to all for your opinions, I hope I can get some clarity on this.

 

[mdocod]

I can tell you from direct experience, that an unmodified maxfire will fit either AWs 17670 or a pair of the RCR123 li-ions....

I can tell you from what other members here on the boards have said, that a 6P will also fit a 17670 or a pair of RCR123s..

In either case, you may have to remove the labels, and it is sometimes still a tight squeeze, but tolerable.

18650s will not fit in either light.

17670s will usually provide longer runtime on those cree drop-in modules, but will have less regulated runtime, in fact, in most cases, a single 17670 driving a cree drop-in will in a steady state of dimming throughout the run, but still makes for a very useful long run. a pair of RCR123s will usually provide a regulated output throughout the duration of the run, but will suddenly drop-off when the protection kicks in.

In either case, try not to run the light down till the protection kicks in, they really should be charged before they get that low.

As for 18650s.... For the 6P you could buy a 1x18650 leefbody from lighthound with C head and tail. For the maxfire, is it possible to remove the stock metal sleeve and hone/bore/grind out enough material, then build a custom sleeve from thin gauge copper sheet stock. (available at places like hobby stores) to accommodate the larger cell. I did it to one of my maxfires with good reliable results, I run an 18650 and a HO-4 in one of mine.

 

[FlashKat]

Very few flashlights will accept the diameter of the 18650 battery. You need to measure the inside diameter of the body to see if it measures over 18mm. If not then as suggested by AndyTiedye buy 17670 batteries.
Edit: I see Mdocod figured out your answer.

 

[Eskimonio]

Thanks all for the input...you guys just saved me some wasted money.

 

[cy]

greatest danger using li-ion cells occurs during re-charging
please consider reading link below..

 

[FlashKat]

I am curious...Everyone here talks about the danger of li-ion batteries, but how many people have actually experienced a battery blowing up?
I have several li-ion batteries and have tried all the different combinations and never had a problem...Thank God!!!.
I have done some really crazy things!!!!

greatest danger using li-ion cells occurs during re-charging
please consider reading link below..

 

[DM51]

I've heard of 2 x cr123as blowing up in peoples lights... help me avoid the problems associated with 2 x cr123as blowing up.

This is not a problem you need to worry about as long as you don't use mismatched cells in the same light. If the cells are the same make, age, type and state of charge, they will NOT blow up. With primaries, buy them in pairs for a 2-cell light, and don't just replace one of them when the light starts to dim - replace both with another matched pair. Obviously, you should follow the same principle for a 3 or 4 cell light.

 

[cy]

again greatest danger using li-ion occurs during re-charging. not in the flashlight. there's many documented instances of venting with flames during recharging of li-ion cells.

li-ion cells will accept current for long as you deliver it to cell. that is until thermal runaway occurs, along with possible rapid disassembly of cell (explosion)

it may be worth your time to read link below...

I am curious...Everyone here talks about the danger of li-ion batteries, but how many people have actually experienced a battery blowing up?
I have several li-ion batteries and have tried all the different combinations and never had a problem...Thank God!!!.
I have done some really crazy things!!!!

 

[DM51]

Just to make crystal clear that in post #10, I was answering a question about PRIMARY (disposable) cells, where the danger of explosion is different to that of Li-Ions.

Primaries can explode inside the light, as outlined in my post, if the cells are mismatched.

With Li-Ions the problem is different, as outlined by cy. Li-Ions are at most danger of explosion when they are being recharged. There are a number of factors that can cause this and these factors are outlined in cy's thread on the subject. There is a link to this in his sigline, and everyone should read it if they have not done so.

 

[SilverFox]

Hello FlashKat,

Keep in mind that CPF is a public family oriented forum. We push safety very hard in an effort to keep those who are not yet up to speed on Li-Ion chemistry, and don't yet have their full portion of common sense, out of trouble.

To answer your question, I have had several cells blow up. Some merely vented, and others added some flame. Premium cells are harder to break down than other cells, and Li-Poly cells are the easiest to get into trouble with.

While I would love to hear your stories, I think it would be best to save them for a face to face get together at one of the CPF gatherings.

Tom

 

[FlashKat]

Hi Silverfox,
I mean no disrespect, and was not planning on sharing any stories, but in reality if you choose not to share stories of why the batteries explode then I am to assume that others will find out on their own as you did by trying something they don't know about, and hope they do not get hurt. You could keep saying be careful, do not mix, etc. I would like to know what caused a battery to explode so I don't make the same mistake. If you are pushing safety then I would recommend never to buy li-ion just to be safe.

Hello FlashKat,

Keep in mind that CPF is a public family oriented forum. We push safety very hard in an effort to keep those who are not yet up to speed on Li-Ion chemistry, and don't yet have their full portion of common sense, out of trouble.

To answer your question, I have had several cells blow up. Some merely vented, and others added some flame. Premium cells are harder to break down than other cells, and Li-Poly cells are the easiest to get into trouble with.

While I would love to hear your stories, I think it would be best to save them for a face to face get together at one of the CPF gatherings.

Tom

 

[FlashKat]

Hi Cy,

I can't access your link. I really want to read it.

greatest danger using li-ion cells occurs during re-charging
please consider reading link below..

 

[SilverFox]

Hello FlashKat,

The basics of working with Li-Ion cells are very simple. Don't over charge, don't over discharge, use a proper charge rate, and use a discharge rate within the capabilities of the cell.

If you violate the basics, the probability of problems goes up.

Tom

 

[cy]

thanks for the headsup.. link is updated.

http://candlepowerforums.com/vb/showthread.php?t=161549

a good part of confusion of li-ion usage is there's not any one standard established. there's a myriad of different size li-ion cells and chargers available. mostly from Chinese suppliers who have little if any liability should something go wrong.

in other words we on CPF are on the bleeding edge of consumer use of loose li-ion cells.

Hi Cy,

I can't access your link. I really want to read it.

 

[cernobila]

I have the Maxfire and 6p each with the DX dropin.

What is the voltage range of the DX lamp.....is it 3.7V only, or 3.7 - 6V, or 3.7 - 9V, or 3.7 - 13V?.....thanks.

 

[winny]

Is there any advantage to using 1 x 18650 battery vs. 2 x rcr123a or vice versa? i.e. longer runtime or brighter light with one setup vs. the other?

In general, given that your flashlight can accept the size and voltage difference, there is a huge advantage using 1*18650 as most development happens here (due to high demands from the laptop industry) and they have much higher energy density than 2*RCR123A.

 

[cernobila]

I have the Maxfire and 6p each with the DX dropin.

Is there any advantage to using 1 x 18650 battery vs. 2 x rcr123a or vice versa? i.e. longer runtime or brighter light with one setup vs. the other?

Firstly, the 18650 will not fit the above lights, both 17670 and 2x RCR123's may. The 17670 will give longer run time but wont be quite as bright, while 2x RCR123 will give slightly brighter output with shorter run time. All this depends on the voltage range of your lamp. If the lamp is 3.7 - 6V then forget about the RCR's.