Final verdict on the MPPT as a faster charging input from a vehicle’s battery?

[PriusFan]

Many portable power stations offer higher maximum wattage MPPT solar charging than through AC bricks or cigarette lighter inputs. Sometimes as high as triple the watts and therefore much shorter charge times.

Just when I think it has been concluded one shouldn’t use MPPT input directly from a non-solar source I watch what Will does at four minutes in the video below (he connects a 30 volt desk input to the MPPT to test the unit):

In the related video below Will also complimented the hack to boost the input/output voltage from a DC source. If one has a pretty consistent DC input from a running vehicle’s 12v battery, and adequate cables for amperage, is there a reason not to use the MPPT input in the way Will does above?

 

[HRTKD]

Methods like this have been proven to work. As long as the power supply voltage and amperage is within the limits of the MPPT, it's OK.

 

[Bud Martin]

Hobotech does the same thing too, you can do it as long as your car power system can supply the needed power.

 

[HRTKD]

Adding to what Bud said (and I should have pointed out before), my Victron MPPT won't initiate a charge unless the input voltage is 5 volts higher than the battery. Once the charge is going, the voltage only needs to be 1 volt higher I believe.

Consequently, most automotive systems aren't going to provide the necessary start voltage for my MPPT.