That Orion charger is a overpriced pos, its only a 50w. The best bang for the buck is icharger, most watt per dollar that I've come across. Don't be scared away by DC only chargers, its simple cheap and easy to make your own power supply. Using a computer or server supply. Realistically speaking for doing a single battery charge you don't need any more than a 300w charger, to do some very quick charging.