Battery question

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.

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.

MrGman said:

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

Click to expand...

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