tarnold wrote:
I have subject jump start, and it indeed will jump a dead battery in a heart beat. BUT if I put a meter across the terminals I see no voltage, tried to use it to run a 12v diesel fuel pump, but nothing. It is Lithium , why canโt I see any voltage coming out?
Jump boxes in car starting mode do not "provide" any output voltage unless they see a voltage of 9V or more.
This is the same issue you get with a lot of the "smart" portable chargers, they will not charge a totally dead battery, there must be some voltage when you connect it.
The idea is to prevent you from causing sparks when connecting to a battery or if you short the jump box cables together or reverse connection.
Therefore they cannot run your diesel pump directly since you pump doesn't present some sort of voltage.
The only exception to this is if your jump box has say a 12V cig power port, then you might be able to power your diesel pump from the cig power port, but definitely not from the jumper cable..
According to the manual it is only a 19Ahr lithium battery, it isn't going to provide much pumping time anyways depending on how much amperage your pump requires.
