Depends on the car, sorry you do not say what age/model, as long as you jump in the start circuit should be OK, because the battery may be a small gell battery under the seat/rear seat by the rear axle only able to get at it by lifting the car
I jumped mine by one lead to the starter red, positive on the pre engage wire and other the the engine block lifting eye (1800 zetec) works fine.
I will fit a battery isolator in the bonnet on the tool tray front side which will allow shut off of the car and an easy jump point in future, I will use an old 24volt Oldham unit from a bus, these are very reliable.
Chris
