Battery question

[Painful Chafe]

I ordered a light from a website. The light I ordered takes CR123's which I have. The light that was sent takes two 18650's but has an extention tube that can be removed and can take one 18500 I think. Even though it isn't the light I wanted I am thinking of keeping it and not deal with the DX/Kai return hell that this site will be like.
Without the extension in it, 3 CR123's will fit and the output will be 9v. The light input is rated to 9v. I haven't turned it on yet. I don't want to blow anything.
Is it safe to turn it on like this. If so will the output be the same as with the 18650's. I want see what the output is like to decide whether I will keep it and then buy some 18650's

I will make a new post about the wrong light sent scenario later. It's pretty funny and CPF'er should know about this site.

 

[MrGman]

You could have put the name and model of the flashlight in your post to help. Some people may have that very same light and given you a direct answer.

It sounds like the light was designed to take 3 non rechargeable primary CR123's for 9V or with the extension tube 2 18650's for 8.4V. The light should work fine on 3 CR123 batteries. Most lights that can take 2X18650 can take 3 CR123's because the voltage sags down on the primaries under a real load anyway. So saying something is rated for 8.4 or 9V isn't really any difference.

Do not put 3 of the RCR 123 rechargeables in there and all should be well.

 

[Kestrel]

Do not put 3 of the RCR 123 rechargeables in there and all should be well.

That's my guess for your setup as well.

3x123A (Lithium primary): 3.0v -> 2.5v under load. 3x2.5 = 7.5 volts :thumbsup:
2xLiIon (pretty much any size of LiIon rechargeable, including RCR123's): 4.2v -> 3.7v under load. 2x3.7 = 7.4 volts :thumbsup:
3xLiIon: 3x3.7 = 11.1 volts :thumbsdow