Rechargeable CR123 Help Needed

[parawolfe]

I have 3 lights that use CR123 batteries. A Fenix TK10, Fenix P1D, Surefire E1L Outdoorsman and I will be purchasing a NiteCore Extreme very soon. I want to be sure that which ever charger and rechargeables I buy will work on all four lights. I have been looking at the "Tenergy 4 Pack RCR123A 3.0V 900mAh Rechargeable Li-Ion Battery with Smart Charger" at BatteryJunction.com. I can't see any problems with this setup but knowing there are more knowledgeable folks in here, I thought if there was, someone could point any conflicts out to me. Thanks

 

[mdocod]

All of those lights should work fine with those cells, I personally lean towards recommending LiFeP04 RCR123 cells in these applications because there are less components to fail (no voltage regulator, no protection circuit). The LiFeP04 chemistry is totally safe and robust. No need for the extra circuits, just top off frequently, try not to over discharge em.

I couldn't find any information on the NiteCore extreme as the website I found for em does not seem to be entirely working right, and the 2 distributors I found have websites under construction so again, no way to see the specifications.

The TK10 will have much better runtime if you buy a set of dedicated 3.7V protected RCR123s and charger for it instead, and I'm kind of guessing that the NiteCore extreme might also be compatible with a 3.7V cell, but have no way to verify that unless I can find a link somewhere to some detailed information about it.

The 3.0V cells you have linked to are actually 3.7V cells with a voltage reducing circuit built in to make them more compatible with CR123 devices. One of the main problems with this is that the charger charges to 4.4V instead of 4.2V like other 3.7V cells in order to overcome the circuit in reverse during charging, seems to me that if something went wrong with the circuit (like it shorted out or something), then the charger would be free to overcharge the cells pretty substantially. Another problem is if you ever add more li-ion cells to your collection in the future, then you need to really make sure that the charger for the 3.0V regulated cells gets used for those cells and those cells only!

The LiFeP04 charger terminated at 3.6-3.8V, so having it around and accidentally using any of the other types of RCR123 in it would not be hazardous, it just wouldn't complete the charger. Accidentally putting a LiFeP04 cell into a charger designed for 3.7V cells (with termination at 4.2V) is also reasonably safe as LiFeP04 cells tolerate overcharge reasonably well.

Eric

 

[Mr Happy]

FYI, the NiteCore Extreme is described here

http://www.nitecore.com/pages/products/nex/

as accepting a 16340 Li-ion cell. With the 16340 it has marginally higher brightness (I doubt you could tell) and 2/3 of the run time compared to a primary CR123A.

 

[parawolfe]

All of those lights should work fine with those cells, I personally lean towards recommending LiFeP04 RCR123 cells in these applications because there are less components to fail (no voltage regulator, no protection circuit). The LiFeP04 chemistry is totally safe and robust. No need for the extra circuits, just top off frequently, try not to over discharge em.

I couldn't find any information on the NiteCore extreme as the website I found for em does not seem to be entirely working right, and the 2 distributors I found have websites under construction so again, no way to see the specifications.

The TK10 will have much better runtime if you buy a set of dedicated 3.7V protected RCR123s and charger for it instead, and I'm kind of guessing that the NiteCore extreme might also be compatible with a 3.7V cell, but have no way to verify that unless I can find a link somewhere to some detailed information about it.

The 3.0V cells you have linked to are actually 3.7V cells with a voltage reducing circuit built in to make them more compatible with CR123 devices. One of the main problems with this is that the charger charges to 4.4V instead of 4.2V like other 3.7V cells in order to overcome the circuit in reverse during charging, seems to me that if something went wrong with the circuit (like it shorted out or something), then the charger would be free to overcharge the cells pretty substantially. Another problem is if you ever add more li-ion cells to your collection in the future, then you need to really make sure that the charger for the 3.0V regulated cells gets used for those cells and those cells only!

The LiFeP04 charger terminated at 3.6-3.8V, so having it around and accidentally using any of the other types of RCR123 in it would not be hazardous, it just wouldn't complete the charger. Accidentally putting a LiFeP04 cell into a charger designed for 3.7V cells (with termination at 4.2V) is also reasonably safe as LiFeP04 cells tolerate overcharge reasonably well.

Eric

Eric,

So then you would recommend me buying the "2 RCR123A 3.0V 750mAh Rechargeable LiFePO4 Li-Ion Batteries with AC/DC Smart Charger" even though it is 750mAh and not 900mAh? And this kit would work with all four of the CR123A light I have? My main concern with rechargeables is logistics. I want one kit that will work well with all 4 lights otherwise I would stick with primaries. I'm also trying to find a "GE Sanyo Eneloop Quick Charger w/2AA batteries" and then also pick up a 4 pack of GE Sanyo Eneloops. It seems they haven't made it to the mainstream retail stores yet. I noticed Circuit City had the batteries but not the charger. Fry's had both but are now sold out. If you know of any places stateside that has them I would appreciate any recommendation. Thanks.

 

[parawolfe]

All of those lights should work fine with those cells, I personally lean towards recommending LiFeP04 RCR123 cells in these applications because there are less components to fail (no voltage regulator, no protection circuit). The LiFeP04 chemistry is totally safe and robust. No need for the extra circuits, just top off frequently, try not to over discharge em.

I couldn't find any information on the NiteCore extreme as the website I found for em does not seem to be entirely working right, and the 2 distributors I found have websites under construction so again, no way to see the specifications.

The TK10 will have much better runtime if you buy a set of dedicated 3.7V protected RCR123s and charger for it instead, and I'm kind of guessing that the NiteCore extreme might also be compatible with a 3.7V cell, but have no way to verify that unless I can find a link somewhere to some detailed information about it.

The 3.0V cells you have linked to are actually 3.7V cells with a voltage reducing circuit built in to make them more compatible with CR123 devices. One of the main problems with this is that the charger charges to 4.4V instead of 4.2V like other 3.7V cells in order to overcome the circuit in reverse during charging, seems to me that if something went wrong with the circuit (like it shorted out or something), then the charger would be free to overcharge the cells pretty substantially. Another problem is if you ever add more li-ion cells to your collection in the future, then you need to really make sure that the charger for the 3.0V regulated cells gets used for those cells and those cells only!

The LiFeP04 charger terminated at 3.6-3.8V, so having it around and accidentally using any of the other types of RCR123 in it would not be hazardous, it just wouldn't complete the charger. Accidentally putting a LiFeP04 cell into a charger designed for 3.7V cells (with termination at 4.2V) is also reasonably safe as LiFeP04 cells tolerate overcharge reasonably well.

Eric

Eric,

So then you would recommend me buying the "2 RCR123A 3.0V 750mAh Rechargeable LiFePO4 Li-Ion Batteries with AC/DC Smart Charger" even though it is 750mAh and not 900mAh? And this kit would work with all four of the CR123A light I have? My main concern with rechargeables is logistics. I want one kit that will work well with all 4 lights otherwise I would stick with primaries. I'm also trying to find a "GE Sanyo Eneloop Quick Charger w/2AA batteries" and then also pick up a 4 pack of GE Sanyo Eneloops. It seems they haven't made it to the mainstream retail stores yet. I noticed Circuit City had the batteries but not the charger. Fry's had both but are now sold out. If you know of any places stateside that has them I would appreciate any recommendation. Thanks.

 

[mdocod]

the 900mAH cells aren't 900mAH, and the 750mAH cells aren't 750mAH,

realistically, the 900mAH cells might be 500mAH at best, and the 750mAH LiFeP04 cells are probably closer to 350mAH.

So yes, the LiFeP04 cells will probably have less runtime than the "900mAH" cells, but both are severely overrated regardless.

The bottom line is that when you switch to rechargeable cells in lights that were intended for use with CR123s, you loose a LOT of runtime, this is why I'm ALWAYS pressuring people to make the rechargeable decision BEFORE building up a collection of lights so this doesn't happen. Not to mention, getting on peoples case about recommending lights to newcomers all the time that have lousy rechargeable options. 18650 powered lights are about the same size as 2xCR123 lights, and have about the same runtime as well.

Here's something to think about:
2 "750mAH" 3.0V LiFeP04 RCR123s (350mAH) cells will have about 2 watt-hours of stored energy.
2 "900mAH" 3.0V LiCoO2 RCR123s (500mAH) cells will have about 3 watt-hours of stored energy.
2 3.7V RCR123s (AW/battery-station) (550mAH true capacity) will have about 4 watt-hours of stored energy
1 "2200mAH" 3.7V 18650 (true 2000+mAH) will have about 7.5 watt-hours of stored energy.
2 CR123 primary cells will have about 6-9 watt-hours of stored energy (depending on brand and load).

The LiFeP04 cells have the worst of the bunch, but since they are rechargeable, runtime hopefully wouldn't be as high on the importance list anymore since you can always top em back up or carry some spares.

If you would really like that extra runtime from the 3.0V "regulated" cells (the ones rated 900mAH), then it may very well be worth going that route, just please make sure to never use that charger on any other li-ion cells.

Eric

 

[parawolfe]

Eric,

It sounds like the "2 RCR123A 3.0V 750mAh Rechargeable LiFePO4 Li-Ion Batteries with AC/DC Smart Charger" is the way to go then. I don't mind the need to recharge a bit more often. After all they are rechargeable. I just wanted to make sure that they would work with all 4 of the lights that I have. It's a logistics thing, I don't want a 3.7v kit for this light and a 3.0v kit for that light and a Eneloop kit for that light, etc. I just want a RCR123 rechargeable kit and a AA rechargeable kit. I don't use the lights in any professional manner so runtime isn't a matter of life or death. Now that I've aquired a few lights I don't want to burn up a lot of $ on primaries and decided rechargeable would be a more economical way to go. I understand to you buying the light before deciding how you are going to power it is putting the cart before the horse but to me it was more like mission creep. I thank you for your help and your knowledge you were very helpful.

 

[Ninjaz7]

Thanks Mdocod for taking the time to explain...very appreciated :thumbsup::wave:.

 

[eng_driver]

It sounds like the "2 RCR123A 3.0V 750mAh Rechargeable LiFePO4 Li-Ion Batteries with AC/DC Smart Charger" is the way to go then.

I went the Tenergy LiFePO4 route. They seem to run okay so far. The problem is that the specs at that link claim:

Maximum discharging rate:< 550 mA

Most lights draw more than that. There is a thread on it at:

http://candlepowerforums.com/vb/showthread.php?t=184282

I haven't seen any expert advise regarding the discharge rate there yet.

BTW, I got mine here:

http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1877

It's a little cheaper if you need 6 cells.

 

[mdocod]

I wouldn't worry too much about that maximum discharge rate for the LiFeP04 cells, I'd call it a guideline for best results. Like squeezing from the bottom of the tube and flattening as you go up does anyone really do that!

on LiCoO2 cells (3.7V RCR123s) it's important to follow the 1.5-2C rule for safety reasons.

LiFeP04 cells are pretty safe regardless. The draw on most LED lights is pretty reasonable, possibly up to around an amp or so. These cells couldn't be much different than the ones AW is selling, he had a chart posted with their discharge behavior all the way up to 5 amps as I recall. If it makes you feel more comfortable, you might check out AWs "RCR123 with safe chemistry" sales thread over in the marketplace dealer section.

 

[eng_driver]

The draw on most LED lights is very reasonable, but it does go as far as 1.5C past the Tenergy specs. As I mentioned in the other thread, it may well just stress the cells beyond the claimed 2000 (or 1000 according to batteryjunction) recharge cycles.

The LiFeP04 cells are very safe compared to LiCoO2, especially in multi-cell lights. Although I am satisfied with the Tenergy cells so far, there really is no expert opinion that I know of regarding the discharge rate yet.

 

[parawolfe]

With all these uncertainties about the various rechargeable RCR123's I think I'll just stick to primary CR123As. I'll just buy them in bulk from batteryjuction.com. In the future I will probably lean more toward buying lights that use AA batteries. I ordered a Sanyo Eneloop Quick Charger that comes with 2xAA batteries and an additional 4 pack of AA Sanyo Eneloop batteries. The term "Quick Charger" is a bit of a stretch though, 4.2 hours to charge 2 AA's.