I have a pair of 120W solar panels on our roof, and they run through a solar regulator. I would NOT want a solar panel of any significant wattage connected directly to the battery as the battery could be dangerously overcharged. Many (all?) solar regulators have some intelligence in them so they will put lots of amps in to the battery when it's low, some when it's close to full, and trickle charge when almost full...then no amps whatsoever when the battery is fully charged.
Do you happen to know how many watts the solar panel is?
Chris