What everyone is neglecting to see here, is that the current out in AC is 1/10th the 12VDC current. So sure, everyone wants to gripe and complain that 1.25A/150W IS TOO SMALL. So double that, you have now effectively quartered or worse the remaining current from the alternator. The battery can handle loads well enough, but in worse weather, and several starts/stops, it could get dicey. I know my outlet only works with the truck on. Hook an inverter directly to the battery, and you are asking to be stranded in a parking lot somewhere when you forget to turn it off. Car design is all about managing the balance of creature comforts, production costs, and efficiency, while minimizing service calls and warranty repairs.