I have read that there is a way to raise the voltage by adding resistors. (Still searching) I have also read that you can combine the output wires to the voltage you needed. My yellow wires currently puts out 10.8v and orange wires puts out 3.0v so total would be 13.8v, just like a standard bench top power supply.

I am currently using a 13.8v Samlex 6 amp Power Supply which is just enough for 1 dc charger.

If sucessful 34amps from the converted PS would be Plenty.

Comparing the guts of the two power supply. The benchtop PS has bigger power caps and large transformer, while the PC PS has smaller power caps and smaller transformer. I kinda find it odd that the PC power supply gives out more amps than benchtop power supplies.