Dear Sir,
bought 2 of this converters, one to power my raspberry pi and one to charge a 12v lead acid battery (due to its ability to limit current).
The first works as soon as i’ve leaved the raspberry attached to its output and then plugged the main power (before i always power the circuit first and then attached the raspberry). Now the output power is 5.1v as i’ve regulated until I plug in the raspberry, it works few istants and then the power lows down to 2v.
Raspberry is OK because now it’s powered by an usb hub.

The second one (battery charger) has a similar issue. I’ve regulated the output voltage to 14v as i needed, then i’ve power down the ‘charger’, attached the battery and plug in the charger. The output voltage raises to 37v (when the input was 24v) and no way to regulate even without anything attached to output.

The second one was refounded by Amazon, the first i don’t ask yet to be refounded.

Regards.