You're forgetting about voltage. AHr is only half of the equation when looking at energy storage, you really need to think about kwh, which is more useful here.
Let's say you can pull half of the energy out of the batteries safely, so 50AHrs each at 12 V gives you 1200 watt-hours or 1.2 killowatt-hours. Your EVSE draws 1.2 amps at 120 volts, for 1.44 killowatts. If you want to figure out how much time you'll get before you run empty, just take the total energy and divide it by the rate of usage, so 1.2 kwh / 1.44 kw = 0.83 hours, or about 50 minutes.
Your LEAF battery is probably around 75 Ahr or so but has WAY more energy stored than your little 100AHr batteries because the voltage is 30 times higher. Compare 75Ahr x 360V = 27kwh to the 1.2kwh present in your batteries. It's pretty clear you'll need substantially more storage and generation to charge your car for more than a tiny bit using solar.
Your original calculation can be useful, but remember that you'll put 12 amps out of the inverter, but going into the inverter you're going to have to pull 1440 watts out of the batteries, or 120 amps. Again it's clear your 100Ahr of batteries won't last long with 120 amps coming off them. 100Ahr / 120 amps = 0.83 hours = 50 minutes.
2015 SV w/ QC