EXTENSION TUBES
I’ve stumbled on a few battery extension tubes on Amazon. No idea on which flashlights they fit.
Anyway my question: I really like compact flashlights like the absolutely great Convoy BD4 that was suggested on this forum(thx). The output of that little giant is good for most of my uses. I’m now looking for a similar flashlight that has an optional extension tube. Extra battery life is a bonus but I’m looking for a tube that increases lumen output. I prefer a real 18650 light not a 26650 light with a plastic tube because I only have 18650 cells and 18650 is a little more compact.
LENSES
I really like my Convoy BD4 but the flood with could use a little improvement.
Are there spare lenses that give a different flood diameter?
Is there a Convoy BD4 review on this forum? If so I would like to add my experience with it.
Be careful about adding extension tubes to some flashlights, some drivers (if not most) can’t take the extra voltage. I know the Thrunite TN11S comes with an extra tube so it can take 2x18650, or Convoy L4
Yeah, I’m aware of the danger of over voltage.
But I saw one flashlight which had stated in it’s specs 3.7-18v
Will increasing the voltage always increase lumen output or will the driver just reduce voltage to the LED to the standard 3.7 v?
Don’t know of any LED that’ll take 18v, unless it’s a multi emiter and they’re in serie, so yes the driver will probably regulate/convert the voltage. Even 3.7v (or 4.2v at full charge) is too high for LEDs if I remember my electronics classes correctly.
To have a brighter LED, you’ll want to increase current. If using 2 cells in serie, a buck driver will lower the voltage and increase the amperage (power conservation in circuits: Vin*Ain=a*(Vout*Aout), a being the efficiency of the driver)