This light is also sold as Mateminco MT18. Check out for pictures and additional data. Either the run time data is completely off, or there is going to be a huge thermal step down (although temp is set at 60 C) accompanied with aggressive reduction in output for the fairly high run time of 4 and 3.5 hours for the highest two outputs. Price is $55, but not sure how to interpret Taobao prices.
Edit:
Based on the run time data, I see a possibility that the light steps down aggressively when reaching 60 C to the 1100 lumen mode (for the Nichia version), and stays there until batteries are depleted. So there is no feedback control for output as a function of temperature.
If so it’s a bit unfortunate that there is no 2500~3000 lumen mode where the light can sustain output fairly continuously.
This is my concern as well, after five or ten minutes this great big light won’t be much brighter than a single xml2 light.
Why wouldn’t they add a few more modes to it? When they added the 1100 mode they also dropped moon. If it was because doesn’t have enough memory for more modes why not get rid of one of the flashy modes? Why handicap the design that way in the first place?
The board Lexel designed will add a lot of functionality to the light but how much heat will the driver make with all those 7135’s when making 2500 lumens? Is eighteen led’s wired 2S9P on a single channel reliable over the long term? Its hard to say how matched the led’s are and if thermal runaway will happen when running the light hot for a long period of time.
A version of this light that made 7500 lumens max would be so much more useful.
you can modify the sense resistors to do less current
I aggree that a sustained level of like 2500/3500 lumens Nichia/XPG3 should be possible, as you can see the temperatue drops after the light stepped down to 1100 lumens
I’m thinking about doing that but it would be tripling the value of the sense resistor to get the mode levels where I want. That might be too much of a change and the driver could stop working. Not sure if it will cause the sense resistors to overheat as well.
The other option I’m cosidering is using your driver and limiting the maximum PWM.Then popping the inductors off the old driver and putting them in series with the led’s.
They would smooth out the waveform and do some load balancing as well. If one set of led’s gets too hot and starts drawing too much current the inductor will heat up increasing it’s resistance. They probably have the wrong parameters for this application so there’s a good chance they’ll overheat.
This light looks perfect for task lighting, but the UI is set up so bad.