I want to power up for a few minutes a 50W LED (37V at 1.5A) from batteries. I have a bank of 10 NiMH rechargeable batteries (total of 12.9V), each in the 2.1-2.5Ah range. I use a DC-DC step up convertor with XL6009 to increase the voltage (made in China, 5euro, Amazon).
I KNOW that I need constant current not constant voltage! This is just an experiment to see if the batteries can keep up for 15 minutes or so.
The convertor is sucking about 2A from the battery bank but it only outputs 0.22A 24V. Why? I was hoping for an output of at least 0.5A. The LED is bright but the radiator is not even getting warm.
The batteries can deliver OVER 4A in shortcut, for a short while.
Summary: the converter draws 10V*2A and outputs 24V*0.22A. Efficiency: 25%!