First I want to say; Fenix rocks!!
second; It's always better to use protected batteries. It's just saver for your light(s).
But it is strange that Fenix does put LVC in the TK21, but not in the TK35.
But like I said, (I) always use protected batteries, so no problems for me
Aye i was pleasantly surprised.
They answer the same night and couldn't do enough to help.
I prefer to use unprotected batteries as the AW 18650's i'm currently using only charge up to just over 4.10v.
I've tried them on 4 of my chargers now and always get the same result, so i'm guessing the cells voltage protection board is kicking in before the charges reach full charge.
Granted 0.1v is neither here nor there.
But if the torch has a low voltage cut-off anways, i may as well save some money and buy unprotected cells.
That way i get a few seconds extra runtime plus i get to save a few quid at the same time.
win win
Wow that's some great info.
My gut feeling is that the TK35 lack of protection is due too the fact that it's a 2 cell configuration minimum
I'm curious as to your thinking behind that please?
In my experience low voltage protection is just as important no matter the quantity of cells installed.
Drop a cell much below 3v and it's pretty much ruined from there on in.
If the LVC was set much lower than 3.2v/cell then i'd start to worry about one cell dropping out of balance to the other, as from around 3.2v the difference in each lithium cells discharge rates tends to change drastically.
This coupled with the fact that if the torch had a low voltage protection circuit it'd obviously only be able to tell total voltage of both cells not individual cell voltages.
So if the torch had say a 6.4v low voltage cut-off (3.2v per cell) you could have 1 cell drop to say 2.8v while the other is at 3.6v, both giving 6.4v still but 1 cell now effectively ruined.