What is the best 26650 cell for this light? I’m currently using Keeppower 5200 mah high drain cells. Would the Golisi 4200 mah make a big difference in output?
Normally that would make a big difference with a FET driver. The cell you have now is one of the weakest 26650 batteries (certainly not high drain) and that Golisi is one of the most powerful 26650’s.
Still, this light seems to have a limiter that keeps high drain cells from burning up the SST-40. I would still not recommend such a powerful battery. You won’t see much difference in output, only measure it. I’d stick with the PLB 5700 (shockli 5500, Keeppower 5500/6000, vapcell 5500) that has been discussed earlier.
Too high a drain battery will work, but might shorten led life.
I’m not sure. People have tested the SST-40 version with 30T and GA cells and the output difference was not a lot. I think it is basically maxing out and the more current just goes into heat which reduces output (output goes down as heat goes up). If you look at the output curve of any led it looks like a roller coaster hill (assuming it survives).
So the SST-40 tends to max out around 9A-10A. We can get this without a high drain cell. Even 8A is pretty close to max output.
The 3v 50.2 on the other hand maxes out around 20A-22A. Someone measured about 15A with a VTC5A. I think someone else got 16A. That means there is room for higher output.
The thing limiting the output of the SST-40 might be the forward voltage of the led and how it controls output. I don’t fully understand it. I believe the 50.2 can go higher than 16A. I’m not sure what the highest drain someone has tried on the 50.2 FT03. You might ask on that thread. Maybe someone tried a Golisi or a 30T. I just don’t remember.
JasonWW nailed it. The SST-40 needs only ~9A to reach peak output, while the XHP50.2 can almost double that figure. With a single-cell light like the FT03, the 3V 50.2 will basically take the best cell that you can throw at it.
The SST-40 FT03 gets warm fairly quickly, but the XHP50.2 version is best kept away from children ;). These are very nice value lights, though, and I’ll eventually buy more of them.