Something is not right there @Winnie.
Amps = Watts divided by volts, nothing changes that simple electrical equation.
Even at 14.8 volts that an alternator more or less peaks at you should see double the amps your meter showed.
Of course undersized cable, faulty connections etc all have an effect on the amps that will flow. You are an electrician or connected to the trade? so will have that covered.
Is it false advertising?