This is a starter kit by Renogy with two 100 W monocrystalline solar panels and negative-grounding 30 A Adventurer PWM charge controller. It especially suits to vehicles with battery negative on the chassis. The charge controller allows for the system expansion up to 400 W so you can add more panels later. On an ideal sunny day, you can expect to get 1kWh energy. Depending on the Sun's availability you can charge a 50 Ah battery from 50% to full in 1.5 hours.
Renogy 200W 12V Monocrystalline Solar Starter Kit w/ 30A Wanderer Charge Controller
2 x RNG-100D Solar Panels
1 x Renogy Wanderer 30 A PWM Charge Controller
1 x 20 ft 10 AWG MC4 adaptor kit, 1 x 8 ft 10 AWG tray cable, 2 x set of Z-brackets, MC4 connectors