Okay so here is what I have done with my DL380 so I can use it as a powersupply for my charging needs!
Okay so first things first you need to bridge these two terminals to signal the PSU to powerup.
Here you can see the yellow wire bridging the power on terminals.
This connection moves little to no current so wire gauge does not matter.
You can easily use gator clips to connect to the contacts and it will work just fine I however added bullet connectors by tinning the ends of them and adding solder to the contacts, after which I did add heat shrink tubing to the bullets for easier identification of the terminal polarity.
The larger contacts are Positive and Negative, one way to remember which is which is by looking at the PSU with the contacts facing you, the outer one will always be positive.
I am designing a plastic cover for it that I am going to be 3D printing and screwing to the end so you can't accidentally short it out. (Note the terminals are live immediately upon plugging the unit into the outlet so make sure that it can't accidentally short out on anything around it)
Ill be posting again for removing the internal ground so you can put two in series.