Parallel Battery Harness vs Parallel Switch: which one is better?

Is it better to connect two batteries using a parallel wire harness which is the direct method or a parallel switch which only allows one battery to be used at any point in time? There is no right answer but one way is more efficient than the other. Using a parallel switch ensures that you are able to fully utilise the full power of your battery every time. Check out our parallel switches here: https://www.falconpev.com.sg/products/battery-solid-state-switch