The total current after connecting two normal 12V 45A batteries in series should be?

When two batteries are connected in series, the voltage of the batteries adds together while the current (amperage) remains the same as that of a single battery. In this case, each of the two 12V batteries has a maximum output of 45A. Therefore, when you connect them in series, you do not add the current ratings; instead, you simply maintain the same current rating of 45A, since both batteries provide the same amount of current.

The total voltage in this setup would be 24V (12V + 12V), while the current remains 45A. This is why the correct answer is 45 Amps; the current flowing through the circuit after connecting the two batteries in series is the same as the current rating of each individual battery.