Flashlights And 123 Batteries Vs. Rechargeable 18650 Batteries

I was speaking with a fellow officer this morning about flashlights. He mentioned that one of his lights takes 2 lithium 123 batteries, which can be a bit spendy, depending on where you buy them. I just happened to mention that a single, rechargeable 18650 battery can be used in the place of two 123 batteries. He was completely unaware of that.

So, I just thought I would ask people here, do you find that most officers, with lights that use 123 batteries, are aware that a rechargeable 18650 battery can be used in its place? Granted, perhaps not the most important law enforcement topic of today, but it can get a little expensive going through disposable 123 batteries.

In all honesty, until a few years ago, I was so stuck on using Streamlight, Inova, or Pelican rechargeable flashlights, that I probably didn't pay much attention to such things myself.

Good topic.

In my little slice of heaven it seems the officers are familiar with 18650 based lights. It seems the local paramedics were the source of their information.
That is the local police anyway.

The state police seem to take a more military approach. Being aware of such technology they choose lights more suited for combat and opt for lights that do either/or.
The thing most of those I've met are unaware of is the 16 and 17 mm fuel cell.

Just a note, not all lights can use both battery types. I regret that my otherwise great Mag Tac only accepts cr123 cells and reportedly not the smaller Li-ion cells (potential for over voltage). An 18650 won't fit due to the diameter. Alternatively my cheek Atactical A1 can't use 2x cr123 cells Atari due to over voltage. That light reportedly uses a linear regulator thus the difference between the led voltage and battery voltage needs to be kept to a minimum. I suspect that is why the A1 gets hot so quickly and had to reduce output so soon.

^^ Have you checked into those K2 LifePo4 RCR's nitedrive?

I use 18mm LifePo's (solar yard light type) in some over driven C sized incan Mags, which provides a nice voltage without the "stomp on the gas pedal" at startup.

nitedrive said:

Just a note, not all lights can use both battery types. I regret that my otherwise great Mag Tac only accepts cr123 cells and reportedly not the smaller Li-ion cells (potential for over voltage). An 18650 won't fit due to the diameter. Alternatively my cheek Atactical A1 can't use 2x cr123 cells Atari due to over voltage. That light reportedly uses a linear regulator thus the difference between the led voltage and battery voltage needs to be kept to a minimum. I suspect that is why the A1 gets hot so quickly and had to reduce output so soon.

Click to expand...

Try a 16650 sanyo cell, i run quite a few of these in my surefire's(6p/g2/g2z/z2/c2)which work well instead of 2x cr123 cells. I use "naked" 16650's, and charge them to 4.35v. They are rated at 2500mah and are good for 4-5a(rough).

bykfixer said:

^^ Have you checked into those K2 LifePo4 RCR's nitedrive?

I use 18mm LifePo's (solar yard light type) in some over driven C sized incan Mags, which provides a nice voltage without the "stomp on the gas pedal" at startup.

Click to expand...

I have the Tenergy 400mAh cells for it. I know Tenergy now makes a 600mAh cell but I'm going to stick with what I have.

ven said:

Try a 16650 sanyo cell, i run quite a few of these in my surefire's(6p/g2/g2z/z2/c2)which work well instead of 2x cr123 cells. I use "naked" 16650's, and charge them to 4.35v. They are rated at 2500mah and are good for 4-5a(rough).

Click to expand...

I've recently been wondering about alternative cells (though I'm not likely to change (see above). I recall reading that the Mag Tac can't handle the higher voltage 16350 (or what ever the number was) cells. I'm not sure how it would handle a 4.2V cell. Either way I won't run a non-protected cells (I was in the battery business a while back).