Newbie battery question - CR123A or 18650 battery?

[skyfire]

Re: Better to use 2 CR123A or 1 18650 batteries?

i like lights that can take either. so it really depends on how the light is being used.
if its one of mine or my family's house/car/emergency lights, i load it with primaries.
if its a daily use work light, i use 18650.

i also used to check my li-ions all the time with my multi-meter. before and after putting it in a light or charger.
i honestly got tired of it:laughing: and the only li-ion i still use are 18650, and never more than 1 in a light.

 

[ecrbattery]

The batteries I have are Cytac 1500mAh

According to my calipers the outside diameter of these batteries is 16.7mm. The inside diameter of the tube is also 16.7mm.

Too tight to fit.

Try another brand of CR123A:

I just measured the diameter of CR123A cells from Panasonic, SureFire, Duracell, Energizer, Rayovac, StreamLight. They all read 16.5mm so they should fit in the plastic tube spacer.


The EagleTac CR123A cell i got measured at 16.7mm so don't use that.

 

[vmaldia]

my friend has a flashlight (one of those chinese generics). It runs off 2 C123a's.

Now rechargeable CR123a's operate at higher voltage then primary cell C123a's so unless the manufacturer says its ok you might destroy a 2 x C123a flashlight. Problem is the manufacturer doesnt say anything on the box. So I dont think we will try it. Since a 18650 is of lower voltage I guess that its safe to try it. Either it doesnt work, it works or its a little less bright but it wont destroy the flashlight

Problem is the 18650 is a bit too fat for the battery tube. Is there another rechargeable thats the same diameter as a C123a but twice as long? I'm amenable to making a spacer if its a bit too short

 

[GhostMatador]

There may be a more recent post of this. This details all the sizes of 18650s so you can find one that will fit your light.

http://lygte-info.dk/review/batteries2012/Common18650Summary UK.html


Sent from my iPhone using Candlepowerforums

 

[Kueh]

Problem is the 18650 is a bit too fat for the battery tube. Is there another rechargeable thats the same diameter as a C123a but twice as long? I'm amenable to making a spacer if its a bit too short

There are LiFeO4 16340 cells, but you will need a special charger for those.

Cell voltage

• Min. discharge voltage = 2.8 V
• Working voltage = 3.0 ~ 3.3 V
• Max. charge voltage = 3.6 V

They will probably be safe for that flashlight. Bonus that they are considered safer cells.

 

[Overclocker]

my friend has a flashlight (one of those chinese generics). It runs off 2 C123a's.

Now rechargeable CR123a's operate at higher voltage then primary cell C123a's so unless the manufacturer says its ok you might destroy a 2 x C123a flashlight. Problem is the manufacturer doesnt say anything on the box. So I dont think we will try it. Since a 18650 is of lower voltage I guess that its safe to try it. Either it doesnt work, it works or its a little less bright but it wont destroy the flashlight

Problem is the 18650 is a bit too fat for the battery tube. Is there another rechargeable thats the same diameter as a C123a but twice as long? I'm amenable to making a spacer if its a bit too short

the best rechargeable option for 2x CR123A lights! KeepPower 16650 (sanyo UR16650ZT cell). same length, same diameter

forget about using low-capacity 16340, two of which always end up being a lot longer than 2x CR123.

2x lifepo4 16340 have even lower capacity, are unprotected, not exactly a good idea to use in series though lifepo4 is a "safer" chemistry

 

[kbuzbee]

Problem is the 18650 is a bit too fat for the battery tube. Is there another rechargeable thats the same diameter as a C123a but twice as long? I'm amenable to making a spacer if its a bit too short

There are also 17650s that should fit if you can't find an 18650 that will. I put one in an old Fenix PD30 and it works great. I'm not a fan of running two CR123s in series.

Ken