My LED driver keeps blowing up when connected to a Lipo battery
You set a current limit on your (I assume) lab power supply (what you called a “power generator”) so to obey the current limit, that set the output voltage to 7 volts. This is what your LED driver worked correctly with.
The way a current limit works is to reduce the voltage until the current drawn by the load is under the limit. By Ohm’s Law, this is they only way to reduce the current.
You then tried to feed it 14-15 volts and it started smoking. Clearly, despite the specs from the seller, it cannot handle that voltage. The same thing would have happened if you raised the current limit on the lab power supply so it was able to put out 15 volts.
You bought a piece of crap. Sorry, that’s how I see it. Either feed less voltage in or buy a better quality driver.