I believe the forum is misleading people due to much concentration on Ampère, and never on Watts. With 2*18650 you will have more runtime plain and simple since the available energy is doubled now. The driver is stepping down so it's all ok.
yes ,right ,thanks for your explanation
Its not the energy that is doubled but the volts. How much added runtime can I gain with this tube extension ? I doubt its twice like in parallel connection.
The answer should be in the product page.
Watts ring a bell to you?
Two batteries means twice the energy (Wh) compared to one battery no matter if you put the cells in series or parallel. If the driver have similar efficiency as with one battery and the emitter sees the same current you will get twice the runtime.
On low and medium, you will roughly get twice the runtime. I say roughly, because in order to get a more accurate picture you would have to know driver efficiency and output on the various modes with various input voltage. Or do a runtime test (preferably with a graph showing output).
On high you will get more runtime AND more output. Not more peak output though (still 3A max). Using only a single cell will make the light fall out of regulation after a certain amount of time. Normally that does not take much time. When using the extension tube you will maintain the full 3A to the emitter even when battery voltage becomes low.
If you resistor mod the light (for about 3,65A) then a single cell will make the light fall out of regulation almost instantly (depending on cell). With the extension you can enjoy using two cells, and get say 3,6A to the emitter every time you switch to high.
Questions to Simon:
1. Does the LD-34 driver in the L4 have low voltage warning for two cells? If yes, how does it work?
2. Does the LD-34 driver in the L4 have low voltage cut-off when used with two cells? If yes, at what voltage?
Very interested in the answers to what RaceR asked myself if you know the answer Simon. I figured the light would have a nice long non-reducing high output with two cells, but didn’t think to ask if the low battery protection worked with it and at what point/mechanism.
1 CELL ———–3V or so
2 CELLS———6V or so
OK
Thank you for the explanation, it is logic but I was not 100% sure.
Omega_17
Watt=Amp*Volt
8.4V*2.6Ah=21.84Wh (2 cells in series)
4.2V*5.2Ah=21.84Wh (2 cells in parallel)
Efficiency of the driver and capabilities of the driver are another thing, but the energy is doubled as I was saying initially.
Yes that I understood but I was not sure if it was really useful to the driver. And yes I read posts here saying volts are only for the intensity not the runtime, ofcourse it depend of the driver and setup.
But how about the effiency of the driver versus parallel connection ? Is it safe to let the batteries stack for long time in the flashlight ? Sorry for the noob questions. :nerd_face:
Does anyone know if this extension will thread on to an S8 body?