18650/CR123 compatibility?

[Buff]

What makes a light able to use both 18650 and also CR123 batteries other than two CR123 are the same size as the 18650? I have a light that is able to use both and described on the site as being so capable.
I wish all my 18650 lights had the option.
Is it the use of a compatible emitter as opposed to an incompatible emitter?
Inquiring minds want to know.

 

[ghostguy6]

An 18650 has a diameter of 18mm while cr123's had a diameter of 16mm. Lights that can both 18650's and Cr123's are bored out to an 18 mm diameter while CR 123 lights have a 16mm bore. The 18650 has a voltage of 4.2 volts when fully charged. Cr123's are generally considered to be 3 volts each so 2x3 would be 6 volts for a set of batteries. Rechargable 123's could be as high as 4.2 each for a total of 8.4 volts. In order to run both your light would need circuitry capable of supporting the voltage range.

 

[orbital]

+

It's an input voltage factor only. Some things are up to 4.2V only

Careful when some guy says you can just pop in two cr123s' in a pinch and you end up blowing your driver.

 

[Buff]

Yes thanks. Maratac customer support got back with me and literally had the same answer. Their Ace Beam collaboration 33rd anniversary light claims it can use both. The EZ Throw light says only 21700/18650 with provided sleeve.
Was worried the gifted EZ throw i gave my son would be tossed into a drawer or glovebox so i took it back and ordered the Ace Beam so he can use the CR123's.