why do rcr/cr123 act differently in different led lights?

just to add to my growing collection of stupid questions.
i want to know how come the jetbeam pc10 like other lights will only work at full capacity (higher lumens) with a rechargeable battery (rcr123) over a non rechargeable (cr123)
while some lights will only work at full capacity with non rechargeable cr123 batterys over rcr123s?
.... and u only usually find this out when u read the box after u buy it :ironic:

Because cr123 and rcr123 are completely different batteries which happen to share approximately the same size dimensions.
RCR 123 is 4.2v fully charged, and are rechargeable.
CR123 is 3v fully charged, and are not rechargeable.

RCR123 typically has about half the milliamp-hour capacity. Normally about 750mah.
CR123 typically has 1400-1500 mah capacity.

Not all lights can even handle the two different voltages safely.
And the lights may very well behave quite differently on the two different voltages.
Run time with the RCR123 will always be less.
Brightness may be brighter on RCR123, but not always.

In some lights which go direct drive at voltages above their regulation limits, they well definitely be brighter as long as they don't fry the light. And this allows the manufacturer to claim higher lumen output with these batteries, which helps sell the light, even though the user might not be fully aware of the details.

That's a pretty good response.

Just to add, different lights have different drivers. Some are buck. Some are boost. Some are both buck and boost. Some are more efficient at certain voltages than other. It just depends on who programmed the light and which battery/s they had in mind when they did it.

it was a good response thanx guys, it was tripping me out

Another big difference is that the protected rcr might shut down suddently and leave you in the dark to prevent over discharging the cell. It always sucks when that happens. I dont like to drain my cells until the procection kicks in, but sometimes it happens. A unprotected rcr will not do that, but it will let you run the battery too lo, and then it can be dangerous. The next time you rechage it, you might actually be arming a bomb So unprotected cells needs a lot of care if you want to be on the safe side. Always check the voltage.
The IMR 16340 is another type of "rcr", It can deliver huge amounts of amps. It uses another chemestry and is regarded to be pretty safe, but they are also unprotected so voltage check is needed. It's only around 500 mah capacity, so runtime is even less than the normal rcr, but it can really take many small lights to another level in terms of pure brightness.
"16340" is the dimention of the battery, 16mm diameter, 34mm long, 0=cylindrical shape. ~Same dimentions as a standard cr123.

A cr123 can be drained.

If I have a Klarus XT11, and it states that the 16340 is not recommended, does that include rcr123s as well? I understand the differences, but just want to confirm as to not harm my new purchase. I'm tempted to use Tenergy rcr123 900mah. Thanks in advance.

16340 and RCR are usually the same thing. 16340 is a size description, which usually implies its a 3.7-4.2 max voltage rechargeable battery. But not always. I looked at the Klarus and it seem to support 16340's. At least the specs I saw did. I imagine they are recommending against using two 16340's because of the high current draw. 2 batteries "can" be dangerous if you don't keep them well matched. A single protected 18650 is much safer. If I was going to use 2 16340's, I'd use IMR cells.

Brasso said:

16340 and RCR are usually the same thing. 16340 is a size description, which usually implies its a 3.7-4.2 max voltage rechargeable battery. But not always. I looked at the Klarus and it seem to support 16340's. At least the specs I saw did. I imagine they are recommending against using two 16340's because of the high current draw. 2 batteries "can" be dangerous if you don't keep them well matched. A single protected 18650 is much safer. If I was going to use 2 16340's, I'd use IMR cells.

Click to expand...

Thank you for the information and the recommendation as well.