When connecting a 4 channel relay to a Arduino Pro mini, there is a noticeable power drain from the board when relays are active. This is clearly visible as the 16x2 LCD dims. I remember reading that this could damage the Arduino, is this true?

In any case, since the entire project will be powered by a rechargeable 12V battery, I bought some buck converters to lower the voltage from 12V to 4.66V (this is what I identified the output to be from the Arduino, I even tried increasing it to 4.8V), so I can power the relay switch directly instead of going through the Arduino.

However, the relay does not power on and I have no idea why.
Can someone help me understand? I'm new to this.


[![4 channel relay][1]][1]
[![Buck converter][2]][2]


  [1]: https://i.sstatic.net/SO71C.png
  [2]: https://i.sstatic.net/1DuWJ.png