An actual 'smart charger' (Battery Tender brand is one) helps maintain the battery's health, even when vehicles are driven often. With a 'flooded battery' they help keep the plates clean. How? Alternators and standard battery chargers only charge to 80% for safety reasons. Smart Chargers have special circuitry that allows them to push the battery to 100% charge, helping clean the sulfates that collect on battery plates.What do you do with battery tender to maintain battery? Is it a car that sits or are there benefits for regularly driven cars?