Our previous review was about best and cheap 100W Solar Panels. To charge the batteries from solar panels, you also need a charge controller, which controls the output of solar panels and trickle charges your battery. Solar panels rated at 12V may product 8V to 22V depending on the sunshine it gets. So, if you are using it directly to charge the battery, you may damage it. Also, in the night, battery power may reversely flow into the panel and damage it. Below is the best and low-cost charge controller, which is rated at 30A that you can use for up to 12V360W or 24V720W panels.
AGPtek 12V/24V 30A Solar Charge Controller