The reason for unclarity is the OP has not looked at a 4-hour Intermatic Timer. They are spring wound tick-tick-tick timers and if by god I want one hour five minutes function it's resolution is +-2 minutes. Want 2 hours 25 minutes? 22 minutes? Twist that knob.
Two wires to connect. The knob's shaft and nut allows a hole to be drilled just like in my BORG.
I do not appreciate wasting my time outwitting a Singapore chip programmed in Calcutta. The object is to charge a battery. Flashing lights and Meaningless Menus are for mouth breathers.
Me, the one-and-a-half handed with a drill, crimpers, and 2 feet of 14 gauge wire could turn your wheeled charger into something that could knock that NoGo nightmare on it's sillyass rubber bumpers for $25.00
Is the concept beyond intellect? The instant you fire up a generator you FORFEIT brain-free RVing. People spend hours programming toy must-haves that require more expertise than an Apollo moon lander command module yet 5-year old's deduction how long to charge at a starting voltage of "x" makes them cranky?
Super Cyber Genius Psycopath Miracle One Touch...needs your money. So does your replacement battery store. Don't disappoint them...