[Magician]

I have to add to this thread. I installed 1 panel and then a month later a 2nd.
I have been solar charging 9 months of the year and the other 3 I simply put the belt back on and turn my added toggle switches to the wiring back on for those 3 months. I could charge with a car charger, but it's an added task that I don't feel like doing and only charge this way when I have rainy days.
I have a 13 watt and a 18 watt solar panel in parallel with a controller. It charges the battery much faster than what you'd think. Also, my Civic VX has very little draw on the battery when running. Especially since I EOC 1/3 of my driving distance. I can drive an hour before the battery drops to a level that would even remotely concern me. Most of my trips are 10-20 miles round trip, so the solar option works quite effectively. I don't know the exact fuel savings, but when I take the alternator belt off, I instantly see my tank fuel economy start rising. If I had to take a stab at it, I'd say easily 5-10% savings.