I will tomorrow. I need a break from all this. The thing is, i've discover that when i will plug board via usb IT ALSO gather the power from the output baterry even when switch is off. I measured this by multimetr. That's strange. I tried adding more baterry, i had 18,5V but still was the same. It's not about voltage. I tried to charge this vai USB from POWERBANK 5V. Worked fine ... but i had to have connected external battery to work, even if it was on OFF switch.