Interesting, thank you for testing these my spouse was looking at these and I said to wait. I've sent him the link, hopefully, he will listen.

I love the review. Thank you!

Did u see a difference in the performance of the light itself? Was it alot brighter. I have a tactical flashlight that uses 3 AAA BATTERIES and swapped it with a single 18650 rechargeable. And man the light was alot brighter. I love it. So I think bought a 4 seven maelstrom s18 flashlight it uses 6 cr123 batteries. So I also want to convert them over to 3 16650 batteries or 123 rechargeable. Any suggestions

For you interest, in case you weren't aware the extra bit of length some rechargeable lithium ion batteries annoyingly have is for protection circuits in build , l wonder how often a bad circuit would render an otherwise good battery unusable ?

In most cases, using RCR123 cells will not harm an LED flashlight. This is because well-designed ones have regulation circuits that ensure a consistent power delivered to the LED(s) and allow a wide range of input voltages. Most of my flashlights can use either a single 18650 cell or two (R)CR123 cells with no problem. One can use two 18500 cells or three (R)CR123 cells in standard configuration, and two 18650 cells or four (R)CR123 cells with the extender that allows more or longer cells. In general it's the amount of power that the cells provide more so than the voltage. Of course if you buy $1 flashlights, your mileage may vary considerably. Most of mine cost in excess of $50 apiece.

Great info. Thanks!

16340, 18650 and 14500 batteries work in every newer LED flashlights I've owned. And funny enough, they were all chinese made flashlights. I've been using 14500 batteries in a Ultrafire Cree Q5 pocket Light for 6 years and the bulb is just now dimming.

So it would probably be a bad idea to put rechargeable cr123a's in my night vision?

Would cr123 or a work in my acebeam K70?

Thanks for the info... I've got the same fetish for flashlights! Also, where the heck did you get that flashlight for $1?

I've had this flashlight called NuFlare Rebel 90 that I can no longer find anywhere but some shady Malaysian web site. They use two CR123A, and the light that's put out is a rounded corner square just like yours at 1:41, but it's small about 5 inches. I was thinking about buying rechargable CR123A batteries for it but maybe it's time to retire it? I bought a Streamlight ProTac 2L-X that takes one SL-B26 Protected Li-Ion USB Rechargeable Battery Pack, but the light output is soft and round. Do you know of a flashlight that could take maybe a 18650 rechargable, round corner square light, and that's not so long maybe around 5 inches? Or is the round corner square light due to the lens? Are those swappable?

a battery might measure 4.2 volts but when connected to a large load only supply 3.7v or lower. watch the voltage on a car battery when it starts cranking, goes from like 13 to 9v. Also adding 2 batteries in series does not exactly double the voltage but comes close. also what prolly matters is the material the springs are made out of on the contacters and the physical dimenions of the case since these are effectively current limiting resisters in the flaslight circuit. I would advise people trying this to get the 18350s without button heads and then add a smallish neodidlyum magnet to connect the two batteries toeagher if added in series. this should add about .5-1v of extra voltage drop in the system and also keep the two halfs a bit more secure. careful coz getting the wrong size neodidlym mag can short stuff out and cause a fire. maybe put some kafgon arimid tape around the inside tube once u establish this wont burn ur LED out. ive been wondering coz there are a lot of cheap sofarin headlamps with 2x leds which are only driven kinda low with 3.7v.... they have the same IC with a buck converter that actually has a spec rating for 6v max in, instead of the 3.7 what most light mfg say... so if u can get the voltage down just like half-1 more volt ur pretty much in the margin of error

I've run into lithium cells/batteries that claim in big letters they are "protected" but it can be misleading because the ONLY protection they had was venting. So while the claim was technically accurate, they did not have the circuit that protects from over or under voltage, and when the vent does activate to relieve internal pressure, it ruins the cell.

Is there a safe solution for replacing CR123 Batteries with ReChargeable versions?

Enjoy your videos as I learn and laugh and laugh and learn - good combo. One question, should we celebrate each day as one revolution around the Sun? I'm not trying to be funny or cute, you just got me thinking.

I have that charger, but dont use it, because i have a much better one that tells chemistry, charge rate, voltage, etc, but glad i know about it now, thank you

4:52 you state no evidence of cell protection. There is a groove on the cell indicating there is protection inside... I'm confused as how you came to that conclusion.

the led has a constant current circuitry built in to it

cool

lol Im not allowed to buy flashlights anymore... so I get yah.

You should test these in a legitimate flash light like a streamlight.

Maybe your flashlights rate above 3.7 maybe 🤷🏼‍♂️

4.25v is the charging voltage. Not uncommon for fully charged battery to measure that right off the charger. Run them in the flashlight for a minute to get it back down 3.7. Not dangerous.

i never saw a product in my life that uses this kind of battery lol