Question: 2XCR123A or 1x18650?

[1MillionCandlePOWER]

Hi,
I'm buying a CREE light that can accept 2 CR123A or 1 18650. Now, for maximum brightness, which battery setup should i use? I assume the 2 CR123A because each is 3.6v and linked in parallel that gives 7.2V which will be brighter than the lone 3.7 18650?

correct?

thanks

 

[Grubbster]

Generally:
2Xcr123=brighter
18650=longer running
This is assuming the light will handle that kind of voltage. Otherwise 2xcr123=

 

[Long John]

CR123A are primaries with 3V each.
I guess you mean RCR123 LiIons?

The answer depends on the driver of the light, so what light you are speaking about?

Best regards

____
Tom

 

[1MillionCandlePOWER]

thanks for the replies.

I'm looking into the Ultrafire C2 suppose to handle up from 3 to 9v. Yes i mean rechargeable 123s

 

[knot]

CR123A are primaries with 3V each.
I guess you mean RCR123 LiIons?

LIR123 same thing?

 

[2xTrinity]

thanks for the replies.

I'm looking into the Ultrafire C2 suppose to handle up from 3 to 9v. Yes i mean rechargeable 123s

the way that the Ultrafire C2 works is a buck converter -- that is, it will draw constant power as long as the input voltage is higher than the ouptut voltage (generally 3.7V) Both rechargeable CR123s, and primary CR123s will both perform the same -- maximum brightness the entire time until the cell is spent, followed by rapid dimming (rechargeables generally have lower capacity however). Using 18650 on the other hand causes the light to be regulated initially, but once the battery's voltage drops below a certain point, it will fall out of regulation and gradually get dimmer throughout the runtime, as the light will essentially be direct-driving from then on.

Another flashlight on DX, the EYJ Cree (formerly called "U2 style") uses a boost driver. When using an 18650, it will direct drive initially (and draw more than 1A), but then begin and remain is regulation as the battery input drops below the output.

The best kind of driver is a buck-boost, which will stay in regulation even with 18650s which start out above the output voltage, and terminate below it. Unfortunately, I do not know of any cheap DX lights using buck-boost.

 

[Long John]

LIR123 same thing?

Yes, it means: Lithium-Ions-rechargeable

Best regards

____
Tom

 

[woodrow]

In my head, it would seem that 2x rcr123a's would be the brightest, but I agree with the above statements that it all depends on the driver.

A D-mini is as bright as a M1, even though the M1 runs on 2 batteries.

I know we at cpf all have the tendency to push our personal favorite lights, but that is why I really like my D-mini with PEU's 18650 battery tube. Since the D-mini was made to run on 3.7 volts, the 18650 powers it about full brightness for 3 hours. With my lights designed for 2 rcr123a's, the 18650 is either not as bright as 2 batts at the start...or quickly there after. Thats another reason that the new Pelican 7060 looks good to me as well.

 

[1MillionCandlePOWER]

the way that the Ultrafire C2 works is a buck converter -- that is, it will draw constant power as long as the input voltage is higher than the ouptut voltage (generally 3.7V) Both rechargeable CR123s, and primary CR123s will both perform the same -- maximum brightness the entire time until the cell is spent, followed by rapid dimming (rechargeables generally have lower capacity however). Using 18650 on the other hand causes the light to be regulated initially, but once the battery's voltage drops below a certain point, it will fall out of regulation and gradually get dimmer throughout the runtime, as the light will essentially be direct-driving from then on.

Another flashlight on DX, the EYJ Cree (formerly called "U2 style") uses a boost driver. When using an 18650, it will direct drive initially (and draw more than 1A), but then begin and remain is regulation as the battery input drops below the output.

The best kind of driver is a buck-boost, which will stay in regulation even with 18650s which start out above the output voltage, and terminate below it. Unfortunately, I do not know of any cheap DX lights using buck-boost.

hey thanks, very good reply.
i went ahead and ordered the 123As. So about how many Lumens out of the C2? It doesn't say in spec.

 

[the servents of twilight]

I found this post on the C2 and a few others. Very Informative. http://www.candlepowerforums.com/vb/showthread.php?p=1979179#post1979179

I have the the C2 as well. I just recieved it. I have both 18650 and RCR123s (both unprotected). I am not sure, but I think it is alot safer to use 18650 vs 2 RCR123s. Maybee protected cells would solve this problem?