Fenix HL35 + LiFePO4? (Also: what charger?)

Hi,
I'm still trying to get the hang of all the 'exotic', non-standard AA cells. So, forgive me for asking questions that may be stupid.

First of all, I view the LiFePO4 batteries as a compromise between the Ni-MH AA's and the 14500 Li-ion cells.
The LiFePO4 is higher voltage than the Ni-MH but lower than 14500. While capacity is lower than the Ni-MH but not as low as the Li-ion.
Please correct me if I've got this wrong.

In almost every spec Fenix provides for their flashlights the LiFePO4 is listed as a big no-no. Was I surprised to find out there was nothing of the sort in the specs for my HL35 headlamp. See for yourselves:

http://www.fenix-store.com/fenix-hl35-high-performance-led-headlamp/

Nothing... So, what does it mean? Can I just use LiFePO4 batteries with this light?

I had something like this in mind:

http://www.ebay.com/itm/8-x-3-2V-Li...geable-Battery-for-Solar-Lights-/272047014030

1500 mAh is not so bad, when compared to the 800 I (would) get from their Li-ion 14500 (Fenix). These cells are supposedly 'protected', plus the brand ain't so bad. I've used their Lithium primaries before and they worked great.

Maybe I'm missing something here.. Like, what's the catch? They leak? They blow up? They can't produce enough current to properly drive a powerful LED?

I know I won't get with them the advertised 450lm out of my HL35 but I'm fine with it. I just don't want to make a stupid mistake like ruining my headlamp or getting chemical burns from the hot acid leaking out of the headlamp, running down my forehead and into my eyes...

So, what do you think?

And how do I even charge the LiFePO4 cells? All I have so far is the Fenix ARE-C2 charger. It don't say nothing about LiFePO4. Is it safe for that?

Also, I need the LiFePO4 batteries more for my Nitecore MT10A than the Fenix HL35. Using these cells with this flashlight kinda makes sense to me. I don't need the maximum rated output. And the runtimes with the Li-ion's are too short. So, how about using the 1500 mAh LiFePO4 instead?

In the manual it says "Primary LiFePO4 battery". Here, check it out:

http://flashlight.nitecore.com/html/uploads/ueditor/image/product/MT10A/MT10A_UM_EN.pdf

Like, what's primary LiFePO4? All I know is the rechargeable type. So what's the deal with that? Do you think I can use those Etinesan LiFePO's in my Nitecore MT10A (safely)? And what about the over-discharging?

Thanks!

LiF2 batteries have less energy at same size than regular 4.2V LiPo cells

those cells have a fake capacity!
14500 LiFe have at most 400mAh

18650 LiFe batteries have typical 1500-1800mAh from the big manufactors
18650 4.2V have 3000-3500mAh

I also call bullpie on the 1500mAh capacity of LiFePO4. Phosphate cells typicaly have lower capacity than liion, both in voltage and mAh.
A 14500 with 840mAh has about the same capacity as a 2500mAh eneloop pro, so I would advise a 14500 if you get extra output from liion, otherwise, sticks with the cheaper, more reliable NiMH.

Lexel said:

LiF2 batteries have less energy at same size than regular 4.2V LiPo cells

those cells have a fake capacity!
14500 LiFe have at most 400mAh

18650 LiFe batteries have typical 1500-1800mAh from the big manufactors
18650 4.2V have 3000-3500mAh

Click to expand...

Oh wow...

So this is fake?:

http://www.ebay.com/itm/8-x-3-2V-Li...geable-Battery-for-Solar-Lights-/272047014030

And this is real:?

http://www.ebay.com/itm/4pcs-3-2V-1...rgeable-Battery-for-Solar-Lights/390980052916

Shows how much I know...

Can anyone confirm this?

So, basically, there are no 14500/AA size batteries with true ~1500 mAh capacity and 3V+ voltage?

no the typical capacity should be 600mAh if that is a high quality cell

cheap cells may have only 200-300mAh

I use LFP batteries for everything. I like the safety. And I don't need the maximum capacity because I can go long enough between charges for it not to be a big deal.

For the charger, I use the Xtar VP2/4. I also like to keep separate chargers for LFP and NiMH, so I don't have to worry about switching the voltage or having a dumb "smart" charger.

NIMH and L-Ion have pretty similar capacities at the AA/14500 size actually. Eneloop pros and the large capacity 14500s both have a little over 3Wh of capacity