Many of the budget lights seems to use LEDs on a 20mm star. I don't know the exact ones, and it could vary from batch to batch. Try to find pictures with the light disassembled.
I just replaced the led in my sunwayman t20cs which uses a 20mm star 1.5mm thick. This was pretty straight forward, head screws off without the lense and reflector falling and easy access to the driver. It pulls 2 amps with fully charged cell which might be to high for a nichia? I used a xpg2 on copper noctigon with outstanding results [520lms and 30000lux] . Sunwayman make quality gear and this small mod was easy.