Can I use 18650 connected to CR123A batteries?

[DontCome2MyHouse]

I have a flashlight that takes both 18650 and CR123A batteries. The directions say that I can use (4) CR123A or (2) 18650. Would there be any issue using (2) CR123A connected to (1) 18650?

The reason I ask is because I noticed the 18650 said 3.7V, while the CR123A says 3V.

[J_Dub_503]

I would not suggest it, they can short, leak, smoke, or blow up. It's not even recommended to mix old cr123's with new ones.

ETA a better answer...
"If different types of batteries are used together, or new batteries are used with old ones, the difference in characteristics of voltage, capacity, etc., may cause over-discharge of the battery which is exhausted first, leading to swelling, bursting or fire."

[bzdog]

I have a flashlight that takes both 18650 and CR123A batteries. The directions say that I can use (4) CR123A or (2) 18650. Would there be any issue using (2) CR123A connected to (1) 18650?

The reason I ask is because I noticed the 18650 said 3.7V, while the CR123A says 3V.

Don't do that! Mixing primary and rechargbles is dangerous! There are some stickies in the electronics and batteries sub-forum on Candlepower Forums (CPF) if you are interested in details, but don't do it!

Why would you want to anyway?

-john

[glocktogo]

I go so far as to voltage match my CR123's. Easier on the lamp, better battery life and less heat generated.

[doubletap2211]

I go so far as to voltage match my CR123's. Easier on the lamp, better battery life and less heat generated.

I do the same thing. Buy a voltage meter and check your 18650's or RCR123's.

[bzdog]

The 18650 isn't the same voltage as the non-rechargeable (primary) 123A cells. Don't mix them!

Even if they were, they'd discharge at different rates so you still shouldn't do it!

-john