Hi, I've just bought a Bosch N70 batt for starting. Specs are 135 RC, CCA 300, 90-100 AH. The engine is a 3 cylinder Perkins. I had the idea of putting a small solar panel running through a reg to give it a small permanent charge to keep it topped up. I've seen some of thse panels for this purpose for sale but they are extremely small around 1.5 or 4 watts. Will these be a waste of time on a battery as large as this ??