Best 3.0v RCR123As for AW's Dual Bay Charger AW-138

[AFAustin]

I have studiously avoided 3.0v RCR123A cells, sticking with, instead, all the different varieties of 3.6v cells. I am now, reluctantly, considering taking the plunge---I confess that my like of the little E1B Backup and my strong preference for rechargeables has my thoughts going in this direction.

What 3.0v RCR123A cells would you recommend for use in AW's Dual Bay Charger AW-138 (which I believe is the same as the Ultrafire WF-138)? Is it only the LiFePO4 R123 cells that can be used in it, or will it accomodate any 3.0v RCR123A cells?

Additionally, what exactly are the pros and cons of the LiFePO4s vis-vis other 3.0v RCR123As?

Thanks.

 

[kurni]

I only know the difference between LiFePO4 and other 3.0v RCR123A.

LiFePO4 actually gives 3.2v; probably 3.0 under load. It's using a different chemistry generating lower voltage. It has lower capacity e.g. 500 mAh vs. 750 mAh.

The "usual" LiIon gives 3.6v; when coupled with an in-built step-down circuit it can give exactly 3.0v. The problem is that the circuit consumes power.

LiFePO4 is meant to be 'safer'; e.g. don't explode as the chemistry doesn't vent gas when discharged. I prefer not to use the "usual" LiIon unless it has AW's thermal & pressure protection.

 

[AFAustin]

Thanks, kurni, for that info.

 

[Mercaptan]

The "usual" LiIon gives 3.6v; when coupled with an in-built step-down circuit it can give exactly 3.0v. The problem is that the circuit consumes power.

Usually, AW's RCR123s come off the charger (mine is an ultrafire 139) at 4.2 ish volts.

 

[winston]

Capacity: In the limited sample group that is my battery collection, the average LiFePo has 75%-80% the capacity of its ic regulated counterpart.

Safety: Most voltage regulated cells are protected against the usual: over (dis)charge, current draw, reverse charging polarity, etc. The safety of the LiFePo chemistry, on the other hand, can be summed up by AW's willingness to throw one of his batteries into a barbecue pit with hot coals. Needless to say, that is the single most awesome product testing story I've ever heard. I'm pretty sure "grill medium-well" was not in the design specs.

You probably won't be happy with the runtimes you get with diode-dropped RCR123s + WF-138. They usually take a 4.4v charge, and the WF-138 only does 3.6v and 4.2v.
-Winston

 

[AFAustin]

You probably won't be happy with the runtimes you get with diode-dropped RCR123s + WF-138. They usually take a 4.4v charge, and the WF-138 only does 3.6v and 4.2v.
-Winston

Winston, thanks for the post. Pls. explain---to a non-technical guy---what the quoted portion above means. Is it that all non-LiFePO4 3.0v cells don't work well with the WF-138?

Thanks

 

[gunga]

The W-138 charger charges to 4.2V (normal RCR123) and 3.7V (I think only LiFEPO4 work at that voltage).

The 3.0V RCR123's are actually just normal 3.7V cells that have diode or other circuitry to drop voltage to 3.0 volts. This reduces capacity and many cannot handle high current drain.

THey usually require a higher voltage charger to get over the circuitry (often 4.4V). That is why it's usually recommended to NOT mix chargers and batteries. If you get a 3.0V RCR123, try and get the matching charger. I don't believe the 138 is meant for any 3.0V RCR123 (no matter what Dealextreme thinks).

 

[Lighthouse one]

Almost every batt type asks for a different chager--that's why I have 5 different ones !
I recently got some of the Soshine 3.0 volt batteries from DX :
http://www.dealextreme.com/details.dx/sku.723
THese seem to be better quality- and have a decent amount of power.

I also bought 2 different sets of life po battteries for a buddy. THey need a special charger ( goes to 3.8 volts...drops off to around 3.3 sitting). THey work well- but have less total power (mah)...and will blow a 6 volt incan!
Use them for leds. Either works great- We got the life-po batteries for my buddy's dad...we didn't want to give him anything that might go poof!

These are from Battery Space:http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=3478

 

[AFAustin]

Thanks, gunga and Lighthouse one, for your helpful posts.

Still trying to decide whether to go for a LiFePO4 system, a non-LiFePO4 3.0v system, or just stick with primary CR123As for those very few of my lights that can't handle 3.6v li-ions.

I appreciate all the info.

 

[gunga]

I went rhrough all that, and decided to go LiFEPO4 for a while. I had poor results with a Fenix P2D (Med, Med, High, no low).

I ended up selling my setup and just sticking with normal RCR123s and lights that could handle it.

If you have Surefires etc, and can fit them, I'd go LiFEPO4. Much safer chemistry, and more resistance to over-discharge and can usually handle higher current draw. You may not get proper modes if you use in a Fenix or Olight, but for Surefire type stuff, I'd use em (if they fit in the tube! They often can't).

Otherwise, save the money and get primaries (no free lumens tho. )

 

[winston]

I went rhrough all that, and decided to go LiFEPO4 for a while. I had poor results with a Fenix P2D (Med, Med, High, no low).

I ended up selling my setup and just sticking with normal RCR123s and lights that could handle it.

If you have Surefires etc, and can fit them, I'd go LiFEPO4. Much safer chemistry, and more resistance to over-discharge and can usually handle higher current draw.

That's good advice. I recently had to choose between the two 3.0v options on behalf of a co-worker. I was leaning LiFePo4, and the only reason I got the regulated cells was that there was already a charger for them at the club.
I have heard conflicting reports about max current draws. The datasheet for my LiFePo4 batteries indicate 3C max. That'd make about 1.5A, which I think is about the same as 2C for a 3.7v cell.
-Winston