lites that say "don't use rc123"

was just looking @ the solarforce l2 that is ruduced in $. in reading the specs it says "don't use rechargeagle 123's" i have noticed that same caution on several other lites. why is that?

what's the essential difference between 16340, rc123, and cr123

if that's a ? i don't know the answer

yep. here: ?

:D

I have no clue what kreisler is talking about, so I'm going to try to answer your question...

I guess the lights you are looking at are design to use either one 18650 battery OR 2 CR123A (non rechargeable) batteries (the 2 configurations have about the same length). In certain flashlights, if you would use rechargeable CR123A (i.e. RCR123 or 16340) the voltage would add up to 8.4V and you would fry the driver.

Max voltage of some battery configurations:

One 18650: 4.20V

Two CR123A: 6.0V

Two RCR123/16340: 8.4V

I had always thought that the reason is what Volk said above.

However, solarforce-sales.com says:

Earlier it didn't say anything about 3.0V... Must have been a FAQ since I remember asking them the same thing: "Can I use 3.0V rechargeables then?"

Possible reasons for denying 3.0V rechargeables are:

- some of them are really 3.7V and are "regulated" to 3.0V, however it takes a split second before the regulation kicks in, and that might be enough to damage the led/driver

- rechargeables can run with higher amperage(?)

- or something completely different?

If I'm allowed to speculate I would guess that 3.0V rechargeable lithium batteries comes of the charger at around 3.6V, much the same as 3.7V batteries reaches 4.2V. That is if by 3.0V you mean LiFePO4 batteries:

And then there are some lights that Shiningbeam says "even though the manufacturer says they are not rated for RCR123, rechargeable cr123's seem to run fine in them

I meant Li-Ion, something like these, where 3.6V is regulated to 3.0..3.2V in 12ms.

I'd say it's the 4.2 vs the 3volts .

Most of them were probably written prior to the 3.0 volt rechagables i'd assume they are fine ..gotta remember they are dealing with the general public who ain't real smart ..

By rcr123 I assume they mean 4.2 volt batteries

It also depends if you're using two batteries or not ...A .7 increase may be fine but a 1.4 volt increase may make it all go magic smoke .

Like trooplewis said Most companies woud rather be safe than sorry and have you not calling them whining.. it's easier to just scare the customer into not popping a driver than dealing with the complaints.

CR123s are 3.0 Volts. Rechargable CR123s (AKA 16340s), range from 4.2 volts down to 2.7 as a minimum voltage.

Most lights that are for 1x CR123s will say "no RCR123/16340", but this is ONLY due to heat concerns in most cases. The circuit can handle it just fine.

I have used an itp A1 and Quark MiniX 123 with RCR123s for years with no problems at all.

However, multiple CR123 lights are a different story since 2xCR123 is 6.0 Volts and 2 RCR123s are 8.4 volts. That is pretty significant and may be outside the limits for the Driver. With these lights you should only use 2xCR123s, but best bet is to buy an 1x18650 light instead.

ok i get the voltage thing with 2 cells. but some lites say no rcr even with 1 cell. ur saying not to worry?

also what exactly are the heat concerns?

if the flashlight is cr123a only, it has a boost driver which when fed with volts (than the vf of the led) will simply be direct drive

that *could* damage the led/driver

Usually is safe to use lfp 3,2v instead of primary, they write that just to be safe, but only who know how is/build the driver can be sure

Luckily is almost safe also overcharge lfp batteries but take care and ever use apposite chargers(some have a switch for lico3,7v/lfp3.2v

so would it be safe to say (without any empirical proof) that if the bat v is within the range of the driver that it's ok to put the bat in the tube?

In the case of a linear driver, the differential in voltage between the forward voltage of the LED and the cell voltage is wasted as heat.

With one cell, it's not a big deal - with the two cells, roughly a third of available power is wasted as heat. This is reflected in runtime as well.