I started this thread little while ago, just to scope out a mod for my aliexpress J12. Out of the box stock, my light at 8.4V pulls around 28Watts, and delivers ~1.35A to each LED. The T6 XML will emit ~475 Lumens at 1.35A, for a total of 2375 bulb lumens. It gets warm at the 5 minute mark and needs 8-9 minutes before it reaches "hot to the touch" state. It needs another couple minutes to reach "painfully hot" to the touch. These numbers extend a little if I hand carry the light, with air circulating. So the stock driver is a moderate driven design, I think the sock light is a well thought out balance between output, thermal stability and power consumption.
According to KD specs (which look accurate) this new driver will pull ~55 watts. Factoring in an 80% efficiency (typical for FET-based drivers), this driver should deliver 44Watts to the 5-XML array. That equates to 8.8Watts & 2.6A into each LED. The T6 XML will emit ~800Lumens at 2.6A, for a total of 4000 bulb lumens.
Benkie and I have had some excellent J12 discussions in his "calling all J12 owners" thread here...
https://budgetlightforum.com/t/-/8573
...Where his light draws 55W at 8.4V and pushes his LEDs hard at ~2.5A each. So I think Benkies J12 is a good approximation how the J12 will perform with a ~55W driver upgrade. The idea of HOT 18650 cells (being pushed at a ~6.5A draw) and a HOT heatsink after a couple minutes, doesn't really appeal to me that much. I generally use my J12 as a constant ON, task flood-light kind of thing. So for me a cooler running ~2000 Lumens is very nice. Now if I could re-flash this KD driver to add another medium-high output mode at ~60%, and set the PWM frequency higher that would be really nice.
I would consider 5-XML pushed with 2.6A each more of a short burst only kind of light, like the DRY Turbo.
Question to others regarding 18650 safety.... how safe is it to run two cells in series with a ~6.5A current draw? Is there increased risk of a flame/vent incident using 18650 cells in a ~2C (+) application?
thanks!!!