Do these have OC protection? I don't have one of these nor can see the converter part number, but I'd measure the voltage output and whip out ohms law and a resistor first. You can then determine current, adjust it into constant current mode or if you're satisfied it's not pulling more than 5A put your multimeter in series with the resistor and measure then set the current.
The Fluke 115 says:
DC current from 0.001 A to 10 A (>10 to 20 A, 30 seconds on, 10 minutes off). > 10.00 A display flashes. > 20 A, OL is displayed.
So 5A looks fine to me, but don't use a multimeter to test current on an unknown circuit and if there's the possibility of creating a high current short, well I wouldn't do that.