LD-33 Triple XM-L 2.6A 9-17V Circuit board





Driver is from Intl-outdoor.com

Official specifications:

• Suitable for 3 or 4*18650 or 26650 batteries
• Suitable for 3 LEDs in series
• Step-Down (Buck) driver
• Input voltage: 9-17V
• Output Current and Modes: High (2.5-2.6A) - Medium (700mA) - Low (100mA), High (2.5-2.6A) - Medium (700mA) - Low (100mA) - Strobe - SOS
• Constant current circuit
• Memory function
• This driver does not use PWM
• PCB Diameter: 23.5mm
• PCB thickness: 2mm
• Total height: 15mm
• Cathode (Negative) pad diameter: 6.5mm
• Components height on the cathode side: 2.5mm
• Components height on the inductor coil side: 10mm
• Gold plated contacts
• Low voltage protection: Light will slowly flash at 9V (3 batteries) and 12V (4 batteries)
• Tinned leads

You can change between the set of modes by turning on the flashlight on low mode for about 3 seconds,the light will flash once, then quickly turn off the flashlight and then turn it on.



Measurements

Tested with: 3 Cree XM-L2 in series.
Diameter 24mm
Max. height: 14.7m
In first mode set the driver has: High, medium, low, strobe, sos
In second mode set the driver has: High, medium, low
The mode set selection is done from high mode.
The driver has memory, the actual mode is stored when the light is off for a short time.
A short off/on will select next mode.
Driver is buck only.
Strobe is 15hz


High



With four batteries the driver keeps full output down to about 14.5 volt, then the output drops and at 11.7 volt the low battery warning starts.
The low battery warning will drain the batteries down to 7.5 volt, before it turns off.






With 3 batteries, the driver will first drop in power at 10V and start warning flashing at 9 volt.
As with 4 batteries the low battery warning will drain the batteries down to 7.5 volt, before it turns off.







There is a slight difference in the buck frequency, depending on number of batteries.




The low voltage warning is not a fast flashing, but a slow (2 sec cycle time) ramping up and down.



Medium



On medium the light does not step down, but goes directly to warning flashes.






This works the same way with 3 batteries.









Low




In low mode the efficiency goes down, due to the drivers own power consuption.
Also note that warning flashes increases the current consumption.






In low mode the 3 battery curve does not start at 13V, but at 12.8V. There is a reason for this, the 3/4 battery threshold is just below 12V in low mode.









Strobe




With strobe the lower battery voltage has largest output.
The strobe frequency is 15 Hz.



Sos




The sos mode is nearly unaffected by the battery voltage.


Conclusion

This driver does a good job of driving 3 leds from 3 or 4 LiIon batteries with good efficiency, but I am not impressed with the low voltage warning, it activates at to low a voltage and it does not shut down the light.
This means it is important to use protected batteries (Always a good idea with batteries in series).



Notes

How do I test a led driver
List of all tested drivers