rechargeables for your CR2-based light!

[325addict]

You finally pulled the trigger on such a pleasantly small CR2-based light, and now... you came to the conclusion, these batteries are hard to find and quite expensive! What to do? It's time to get guilt-free Lumens

Currently, I know of two options:

A: DX sells the Ultrafire LiFePo4 cells, that are claimed to have a capacity of 800(!) mAh. You can already guess: this statement is not even remotely true....
Cell 1: 157mAh
Cell 2: 181mAh
Cell 3: 200mAh
Cell 4: 204mAh
Cell 5: 217mAh
Cell 6: 220mAh

These cells require a special charger that offers a 3.6V MAX setting: for instance, the Ultrafire WF-138.

I tried these cells in the 4sevens mini CR2 (as this one features a buck/boost driver it can take up to 4.2V) and had the following runtimes:

high: 12 minutes (output already dropped a good deal!):mecry:
medium: 60 minutes
low: not tested.

As you can see, the quality of these cells varies wildly, I cannot really recommend them, although they are cheap.

B: Then, we have AW who also sells "15266" cells, AKA RCR2.
These are normal Li-Co cells, and can be charged to the "normal" 4.2V and don't need a special charger

AW claims 350mAh for them, which is a conservative rating: I got 356mAh when discharged to 3.0 Volts.
Edit: the second one has 355mAh! THIS is consistent quality!

Consequently, runtime on high especially was much longer: after 20 minutes, output was still OK, but I decided to stop due to quite a low cell voltage. I didn't want to ruin this high-quality cell!
Due to the fact, these lights are not constant power regulated, a higher voltage means a higher output, which in turn means... a higher current consumption! So, medium was clearly brighter on the AW cell, but... runtime was exactly the same, 60 minutes.

NOTE: a runtime of just 20 minutes means a 3C discharge, which is no good for the (Li-Co) battery. Avoid using "high" for prolonged periods of time (a short duration is OK for a Li-Co at 3C).
I ran mine empty nearly non-stop on high, so you have some safety-margin: mine didn't explode

Conclusion: you get what you pay for. My recommendation: go for the AW cells, they really are MUCH better... as you can see!

In the picture below you will see the Ultrafire left, the AW right, with the 4sevens mini CR2 behind the batteries.

Timmo.

 

[cottonpickers]

I agree. AW are the way to go.

I just hope that 4sevens sell enough mini CR2s to make it worthwhile for AW to reintroduce protected RCR2s again. I know I'd buy a couple

 

[Quension]

I tried these cells in the 4sevens mini CR2 (as this one features a buck/boost driver it can take up to 4.2V)

Careful; the entire 4sevens MiNi and Preon lines run on boost-only drivers and are only rated for primaries. Even the LiFePO4s are out of spec and not covered by warranty.

Aside from that, good info, and thanks for collecting it in one place :thumbsup:

 

[scout24]

Thanks for the info! I have one blue RCR2 that I run in my Tasklight, more options are good! Glad the capacity ratings for these are just about spot on...

 

[DM51]

This is one of those threads that could sit comfortably in more than one sub-forum, but on balance I feel it belongs in the Batteries section so I'm moving it there now.

 

[325addict]

Thanks DM51! I was also thinking about WHERE to post it. In fact, it belongs here in the battery-section, but I thought it might be of interest to people who never attend this sub-forum, so... I put it in the LED lights section....
OOPS, sorry, won't do that again :thumbsup:

Timmo.

By the way: I never knew, AW had these RCR2's in a protected variant! I would be in for a few too...

 

[ky70]

The AW RCR2s are not available anywhere, are they?

 

[325addict]

Of course they are (the unprotected ones).

Look for AW's battery sales thread on CPF Marketplace...

Timmo.