I just recived an IR flashlight I ordered.

It lists that it takes one 18650 rechargable battery or 3 AAAs with an adapter. (Which are both included) However, I've noticed that two CR123A battery's ( the same length back to back as the 18650) fit and make the light work.

Are two CR123A  batteries a (good) substitute for an 18650?

Is there an explosion risk using two CR123As?

I've heard of flashlights exploding on rare occasion.

Thanks.

I use 2x CR123 or 1x 18650 in several flashlights interchangeably.

That said 2xCR123 is 6v nominal, 1 x 18650 is 3v nominal. So your light needs to be able to safely operate with those voltage ranges, many do. Some may not.

I have no idea how the 3x AAA adapter you reference works. 3x AAA would be 4.5 volts in ran in series. 18650 can be up to 4.2v so this seems like this would be with in operating range.

The question is - can the light accept 6v input or with that cause it to burn out.

Make Model of light?

It says operating voltage .8 to 4.2 volts.

https://m.ebay.com/itm/OSRAM-7W-940nm-Infrared-IR-Night-Vision-LED-Flashlight-Torch-Gun-Light-18650-CH-/201640932672

http://vi.raptor.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=201640932672&category=16037&pm=1&ds=0&t=1500022544000&ver=0&cspheader=1

I got it for $18.00 from a US seller.

Haven't tried it yet other than seeing if it works but it feels very well built.

I suspect it's the one high tech red neck sells for $200.00.

If the voltage range you listed is correct, then 2 CR123's is a no go.

Order some high drain protected cell 18650's and a charger.

For example:

Nitecore Charger

Olight Battery

Edit: DO NOT use any 18650 batteries with the word "fire" in the name of the battery.

A charger is included with the light.

Is there a reason why to not use the batteries with " fire"" in the name?

Are they high priced? Faulty?

Thanks for the advice.

Chinese crap. I have had those batteries explode and pop out of chargers when I started using 18650's.
Also, the MAH rating on those batteries is a fantasy. The charger I recommended is a smart charger.
It stops providing current to the batteries when the batteries are fully charged. The single and dual chargers
that are provided with "fire" batteries continually provide current regardless of the battery's voltage level.
The "fire" chargers also usually have a flip out AC plug. Panasonic, Olight and Orbtronics are good batteries to
consider. Also, only buy batteries from reputable websites or retailers. The Chinese manufacturers clone batteries. I stay away from
Sony and Efest batteries for this reason. Check out http://www.candlepowerforums.com/vb/content.php
This site and the people on it are much smarter than me when it comes to flash lights.

Thanks for the good advice.

I did notice that even after charging the provided battery ( ending in fire) with the included charger, all night , it still indicated red .( not fully charged)

It wasn't hot or anything and it works in the light;just something is wrong.

Actually nothing was wrong. It just took a hell of a long time to charge. Like 15 hours.

So far, so good.

How do you guys interchange the two types?

The 18650 is too wide to fit inside my cr123 devices, and two cr123 are too long to fit in the 18650 devices.

I tried this with my streamlight protac, surefire g2 (2 of them), a peq15 (for width only), and multiple ecigarettes.

ETA: fwiw the 18650 were also mixed brand/wrap. Mostly nxjo and LG, the "good" ones for vape users. While the lesser quality ones still had the same dimensions.

They fit in all of the flashlights I bought, but like was mentioned; you have to watch the voltage.

So do the c123s the light was designed for flop around in there or what? Since the cr123 is listed as a 17x34.5mm (69mm in series). While the 18650 is of course 18x65mm...

And the 18650s loosely fit by length?

I'm so lost as to how you're making this work.

The info on the chargers are whatnot is good though. For 18650 type stuff, it's probably easier in the long run to buy premium ecigarette accessories as vape shops seem to be everywhere.

They just drop in and no rattle. The spring takes up the slack.

As was mentioned, the light needs to.be rated to handle 6 volts or more; to use 2 cr123as.