Harbor Freight 10/2/50 Amp Battery Charger Review - FAIL

UPDATE: See part 2 for fail reason. Did not work well. Could not supply 50A for emergency engine starting. Relay clicks on and off. The 2A trickle charger was disappointing as well. Charger continues until senses full charge and shuts off. Not a trickle charge. The 10A setting works and charged a battery without issue. Unit seems to get very warm. Front panel is curling up.
Cen-tech item 60581 but HF also has 60653 that looks identical. Says it is a manual charger not an automatic charger. What is up with that?