my chinesee srk clone uses 3*xm-l2 in parallel and 4*18650 in parallel
roche m170 uses 3*xm-l2 in series and 4*18650 in parallel (LD35 -stock driver from roche m170 designed for 3*XM-L2 in series ~$10 in GB store.)
from cree site:
XM-L2 - Typical Forward Voltage 2.85 V @ 700 mA
XP-L Typical Forward Voltage 2.95 V @ 1.05 A
XHP35 Typical Forward Voltage 11.3 V @ 350 mA
XHP50 Typical Forward Voltage 5.75 V White @ 1400 mA (6 V) or 11.5 V White @ 700 mA (12 V)
I ’m not sure about the original idea but if we are to use 4*xp-l in series (i.e. forward voltage 2.95 * 4 = 11.8V) it is almost the same as if we use 3 * xhp35 in parallel.
to put all in a nutshell - we can use “s” or “p” for 18650 . all depends on driver
All true, but going to a non-standard series cell arrangement is probably more $$$. If a boost driver is needed, than the high amps is not going to be easy or cheap.
Really hope we stay on course here - 4 regular 3-4v LED’s (219C, XP-L, XM-L2, etc.), 4 parallel cells: simply, a few LED options, up to 5+K lumens, maybe up to 3.5-4K using 219C’s.
Of course doing the math on the high voltage LED costs probably rules them out from the start. Qty 4 LED’s on copper per light, goal of the light being $40 shipped.
Didn’t know that the m170 has a boost driver.
But still, if the driver puts out 3A (which is pretty high for a boost driver) then its only 1A per led using 3 xhp35 in parallel.
If you use 4 18650 in series and use a buck driver you might get 9A in total or 3A per led.
That is really a big difference.
Yes 4 x regular emitters
Cells in parallel.
But with the integrated shelf and good threading nothing is stopping people to mod it into a XHP, cells series light
Do you mind me asking who you have been in contact with at Thorfire ?
They have an employee who is on this forum named Barry but my communications with them via email have always been answered by someone called Celine, who TBF is very helpful.
Also remember that due to the time difference Thorfires replies will be arrive in the middle of night here (think they are 8 hours ahead of me here in the UK).
I did once actually stay up till about 4am & was able to message Celine via email with virtually instant replies from her.
BTW with regards to the light I would keep it simple ie no onboard cell charging, no power bank facility etc.
Have you given them an expected number of units for the GB ?