If you need to charge a dead battery, a normal charger is the way to go but you do have to watch it so it doesn't overcharge your battery. A trickle charger will take forever to get your battery up to snuff but you won't have to watch it. A smart battery is a combination of the two, not recommended for long term storage but if has some overcharge protection so you don't have to watch it constantly, and it'll get your battery charged faster than a trickle charger.