It's a stretch, but it is sorta home related. I want to add a solar battery charger to maintain the house generator. (house generator is the 'home' part...). I see units from 1.5 watts upwards of 25 watts. It's just a dinko little battery, similar to a small garden tractor battery. The engine is only 10 HP. What 'strength' (wattage?) solar charger should I use so as to keep it charged, but won't burn it up?