I am looking at getting my first 18650 torch. Now the question is, when using say, a Jetbeam bc40 and the batteries start to lose capacity does the light get dimmer, to let you know? Or will the protection just cut in and the torch simply switch off?
The reason I ask is that I was planning on getting just 2 cells, but don't want to be left with a dead flashlight, and no warning.
I hope I have made myself clear.
Marc.
Yes the light is definitely well regulated. The OP asks a good question, does the cut-off happen because the cells are protected or because the driver has a LV cut-off.
Marc think of getting a torch with exchangeable LED (no modding required). either LED module, LED dropin, or LED pill. i dont know about XXXFire lights and LED dropins but P60-style drop-in's are widely available (from US dealers and manufacturers). Brands to consider: Solarforce, Dereelight, Su*efire, Eagletac, ..
i use the Eagletac stuff.
good stuff. (and cheaper than Fenix)
Ok guys thanks for for the replies. But I am looking at getting a BC40.
So if the battery starts to go flat, what happens? could I be stranded with a torch that has just switched off or will it drop to 50% brightness?
Just want to know if I need 2 spare batteries.
Marc.
i guess so. that's the standard with Protected LiIon's. check selfbuilt's review. It's either the light regulation or the cell protection which cuts off the light. If nobody knows the exact answer from personal experience with the BC40, .. gerta which? ;) then try to find the info on cpfmp! ;)
So when your cells start to go flat in your BC40, the light drops to 50% to give you warning?
Marc
Thanks SashiX
I you have answered my question, it does drop to 50%. Good stuff!
Marc.
i dont own any BC40, sorry
Sorry my mistake. Hey Kreisler what does gerta which mean?
Marc.
never mind marc, its an insider *ggg*
If you're using protected cells, you will have sudden cut-off (due to protection circuit in the cell). There's no visible drop in output with protected cells.One second you have full brightness, another second the light turns off.
If you're using unprotected cells, there will be drop in output, when the circuit start to work in un-regulated range (this voltage is usually much less, than the combined threshold voltage of protection circuit from two cells). You can check the runtime graph with unprotected cells here:
http://www.swiatelka.pl/viewtopic.php?t=6325&start=0
Jetbeam BC40 is at the end of first post.
Thanks, Coolperl. I was interested in that aspect too. Actually I suspected that the protection trips and it's not a driver set cut-off.
Ah! ok, well thanks for that. Looks like I shall get 4 cells then.
Thank you, Marc.
thanks for the great link!
Eh? But I thought they were run times for various torches. Not ladies!
And if they were ladies and not torches, where do you put the batteries?
Marc.
ouch
:D
The real dilemma is the polarity.
