Yes, the cell contributes a whole lot, but here I’m starting with the voltage under load of a 30T based on HKJs data and reported Vf values from djozz and other’s. It’s seems safe to me to estimate a 300mV drop is occurring at 20A elsewhere in the circuit. The FET doesn’t seem like a meaningful contributor according to the spec sheet.
If you can, check output of mechanical switch lights with your bypass and compare with tailcap installed. These could show a large difference at times. Those that do though don’t usually last that long.
And those amp draws look more in line with what I’d expect. 5-10 milliohm is typical for a good FET light.
I really think it might be a Samsung 50T, which I don’t know if it actually exists, but we historically were slow to learn of these new cells. One thing I’m hoping for is the ‘s’ line of Samsung 18650s (or even an ‘r’) to make it to the 30 series. I think by now there is room to improve power density and maintain 3Ah
I know this ^ was a while ago, but I want to put one in a light that came with an xhp50, what did or do you use for “centering ring”, or more specifically so the reflector doesn’t short out in the mcpcb? I have been thinking about cutting a thin piece of plastic just so the reflector has something to sit on, would that work?
In what light? I had a few lights that had the Gen1’s 90/70’s in them that I salvaged from older lights/builds… In the FT03 I didn’t use a centering ring… I used Kapton Tape to cover the mcpcb from shorts…I was using the MTG2 26mm boards until Hank came out with the 32mm….
His tests were not done in a lamp/flashlight. They were done in a sphere measuring the raw led with a power supply.
In a battery powered flashlight with it’s added losses (let’s use a conservative 20% loss) you would need 5000 total lumen to get 4000 out the front of the lamp. That would be about 18 amps. Then you need to consider the voltage sag. A decent 21700 might sag to about 3.8 or so. 3.8 x 18 = 68.4. So I would estimate about 70 watt is what a flashlight would consume.
If your talking about a raw led powered from a power supply, you can see that 4000 lumen draws 12 amps at 3.15 volt. Thats only about 38 watts. These not very practical numbers for real world use.
Personally I’d estimate a 30% loss and say you need to push it to 20 amps and you might be lucky to get 4000 lumen out of a flashlight.
These are all my own estimates based on djozz’s test results, as I haven’t ever used or measured this led. Maybe someone who has tested it in a flashlight can give some more detail.
Listing just says SBT-90, not SBT-90.2. Even the datasheet specs included are for the old SBT-90, looks like to me. I sure wouldn't trust a listing like that if it's a SBT-90.2 you are looking for. Can't imagine anyone interested in the old gen of this LED.
What does the 2nd generation sell for, $20 or $40?
That ad shows $17 which seems more like the older led.
Price alone seems to point to it being the older unit.