What should the voltage output be? I’m reading 11.8-12v I realize this is not intended to charge a battery, but it seems higher voltage say 14v would help the starter spin a little faster aiding in startup.
Looking at a schematic for a model 708KVC the cable I mentioned that is cut off goes from battery positive to that “dimmer switch”, then to the output posts of both generators.
Not sure. I never put a volt meter on the output of the jump starter unit. I do remember it worked really well, spinning over those old carbureted car engines from the 70's and 80's, even on really cold below zero mornings.
To me, 12 volts should be enough. Yes, I agree that 13.5 - 14 volts would initially seem better.... However, as the voltage goes up, amperage goes down, and we both know amperage is king when trying to turn over cold engines with thick oil. I realize we're only talking about 1-2 volts so how much difference could it make in amperage output? Probably not much but if we knew the total wattage output of the jump start unit we could calculate the difference. Either way, more amperage is ALWAYS better when jump starting an engine... In my book anyway. Also, 12 volts really doesn't seem low when you consider that's all the voltage an engine starter normally sees while starting an engine because that's what car batteries normally put out.
Lower voltage results in higher amperage. (and visa versa)
It's the same principal of getting 200amps of output from a welder while only plugged into a 50amp receptacle. When you lower the voltage, the amperage goes up. The welder is internally lowering the voltage as you crank up the amperage. (and visa versa)
Put those clamps on a dead car and give it a try. I'm betting it works pretty good.
Don't take anything I say as fact.... I'm just speculating out loud.
