Rechargeable 123a help

Oscar P

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May 22, 2018
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****Posted in the LED Flashlight section before I found the battery section. I apologize for the double post. Mods, feel free to delete the other even if someone has replied to it****

I'm going to do the ultimate sin on a forum. I'm going to ask for help with minimal to no searching on my end, and see if anyone is willing to help me out. But hear me out as I justify my selfishness.

I have multiple hobbies and interests that I pour my research and attention into. Flashlights, are not one of them. I mean that as no disrespect, but I learned long ago that the best way to get best results is to go to the best in the field for advice. So now I'm here. This will likely be my only post once I figure this out. So....

I have two Jet 3M Pro (Military Series) and one Surefire M952V weapon light. All three of these lights are used extensively with night hunting and we are burning through batteries like nobody's business. All three also use the 123A Lithium batteries (two in each light). I have been trying to find proper rechargeable battery options and began researching the things I was reading, but quickly got lost in the details of "protected or unprotected", "18650 vs 14500", "pushing, pulling, or whatever the terms were". I'm needing to find one rechargeable system that can run in all three lights interchangeably and are not going to reduce life expectancy of the equipment or die so quickly that I'm left getting run over by hogs.

Can anyone please help me out with this, while still beating me to death for being a typical internet bum, so that I can stop annoying everyone?
 

ChrisGarrett

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Here's the short answer, as I'm watching a rocket launch--Space X in Cali.

RCR123s are 3.0v cells and 16340s are 3.7v cells, but the latter comes off the charger at 4.20v. This can be problematic for lights/devices that need only ~3.25v and especially so if you're stacking two of them for 8.4v in a light that has a 6.0v driver.

Tenergy and K2 make RCR123s that are direct drop ins for the CR123As. However, they don't have a lot of capacity--500mAh-600mAh and won't last long, even stacked in series. A quality CR123A clocks in around 1400mAh-1550mAh for capacity.

You need to know the max voltage input for any item before you move to the 16340s. They still have lowish capacities, but they do produce a bit more voltage.

If your device states 8.4v, you can use two 16340s, or just try a 16650 3.7v (4.20v) cell that should fit.

Chris
 

Oscar P

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May 22, 2018
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On the Jet website, it is listing the battery as being either "1 18650 or 2 CR123A". I'm assuming this means that it can handle a rechargeable 18650? They even sell a USB rechargeable 18650 for the light.

I'm still looking into the Surefire to determine what it can handle.

http://www.jetbeamlight.com/products_show287.html
Here is the website and model if anyone feels like double checking my understanding.
 

ChrisGarrett

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On the Jet website, it is listing the battery as being either "1 18650 or 2 CR123A". I'm assuming this means that it can handle a rechargeable 18650? They even sell a USB rechargeable 18650 for the light.

I'm still looking into the Surefire to determine what it can handle.

http://www.jetbeamlight.com/products_show287.html
Here is the website and model if anyone feels like double checking my understanding.

Yes, to your first question. With more modern lights, say over the past 5-6 years, manufacturers have gravitated to the 18650 cell, even though it maxes out at 4.20v (3.6v-3.7v nominal). This is the preferred way to go if you don't want to buy CR123As by the gross.

Some police departments and the military don't mind giving out CR123As, so that's why there will be a 6.0v capable driver included.

Some older Surefire lights, like my 6P won't allow an 18650 to fit, so that's where the 16650 comes in (16mm wide, 65mm long). Capacity is less than the 18650, but it's rechargeable and carrying a spare isn't a hardship.

Some people will buy a bored out SF body and use 18650s, but that's added money and I don't like my 6P enough, to pony up the additional scratch. Some will even get an aftermarket P60 drop-in, like I did (Redilast 1.5A 3 mode) that is optimized for 18650s, but I can't use 2xCR123As in the light now, without blowing the driver board.

Most SF lights are optimized for 6v, so that's almost a no brainer. You might lose a little output with an 18650 and its 3.7v, but you might not notice it all that much.

Trade-offs.

Good luck.

Chris
 

HKJ

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RCR123s are 3.0v cells and 16340s are 3.7v cells, but the latter comes off the charger at 4.20v.

That is a very optimistic view, dealers do not use that criterion when selling cells.
It is also very difficult to find 3V rechargeable cells, LiFePO4 is 3.2V
 

Oscar P

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......
Some older Surefire lights, like my 6P won't allow an 18650 to fit, so that's where the 16650 comes in (16mm wide, 65mm long). Capacity is less than the 18650, but it's rechargeable and carrying a spare isn't a hardship.

Some people will buy a bored out SF body and use 18650s, but that's added money and I don't like my 6P enough, to pony up the additional scratch. Some will even get an aftermarket P60 drop-in, like I did (Redilast 1.5A 3 mode) that is optimized for 18650s, but I can't use 2xCR123As in the light now, without blowing the driver board.

Most SF lights are optimized for 6v, so that's almost a no brainer. You might lose a little output with an 18650 and its 3.7v, but you might not notice it all that much.

Trade-offs.

Good luck.

Chris

If I'm reading this correctly, its not going to be likely that I will be able to run the same 18650 in the SF light as I do in the Jet. This isn't a deal breaker as the SF does eat through batteries a nearly the same pace as the Jet lights do. I can compromise a run a different rechargeable battery for the SF if need be, but want to confirm that I'm understanding everything.
 

ChrisGarrett

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If I'm reading this correctly, its not going to be likely that I will be able to run the same 18650 in the SF light as I do in the Jet. This isn't a deal breaker as the SF does eat through batteries a nearly the same pace as the Jet lights do. I can compromise a run a different rechargeable battery for the SF if need be, but want to confirm that I'm understanding everything.

Yes. We have li-ion cells in all sizes. For an unbored SF body, which won't accept an 18650 (18mm diameter, 65mm length) we can use the 16650 cell. I use the 17670 cells in my unbored 6P. It is basically a Sanyo 16650 with a button top (not needed for lights with a spring at the head) and a protection circuit (naked, not always needed) added, hence the 17mm width and the 67mm length.

http://www.mtnelectronics.com/index.php?route=product/product&path=59_88&product_id=384

The above in the newer generation of my Gen. 1 Sanyo 4.30v 16650, which is about 2100mAh in capacity, but charges up to 4.30v sans the protection circuit.

You can charge the linked Sanyo to 4.20v on any particular li-ion charger that will charge up 3.6v/3.7v cells, you just won't get the full ~2500mAh of capacity.

If you buy the naked Sanyo in the link and buy a li-ion charger that can charge 4.35v cells, you can get that full capacity. They have a nominal voltage of 3.8v and can sometimes hold voltage a little longer, which you would want if you run the stock 6v driver (P60 drop-in module) in your SF light.

I'm kind of distilling things down to the Nth degree, but it's really not that difficult. The two Liitokala multi-chem/voltage chargers I referenced above, can charge naked (no PCB) 4.35v cells up to full capacity.

https://www.gearbest.com/chargers/pp_1233873.html?wid=1433363

For ~$20, you can buy two Sanyo ZTA 2500mAh 4.35v cells and one of the Liitokala chargers and not be heavily invested and have the last laugh on the guys running CR123As.

There are other Liitokala chargers listed on GearBest, but they seem to have creeped up a bit in price, plus the dollar is rising!

Chris
 

ChrisGarrett

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That is a very optimistic view, dealers do not use that criterion when selling cells.
It is also very difficult to find 3V rechargeable cells, LiFePO4 is 3.2V

Some are marked 3.0v and some are marked 3.2v. K2 is marked 3.2v and Tenergy is marked 3.0v. The main point being--don't throw two 16340s into a SF light meant for ~6.0v.

I'm trying to speak in generalized terms, but probably should have used '3.2v' vs. '3.0v', however, I'm trying not to confuse the guy who's learning this stuff for the first time. Painting the picture with broader strokes and all of that.

Thanks H.

Chris
 
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