That description may be because the Eco-charger has the word "charger" in its name and they want to make sure you don't think it is, in itself, a "battery charger" in the usual sense of the term. But yes, what you just described is what you want, though as has been noted, you'll have way more starting capacity than you'll ever, ever need with this configuration.
You can't go wrong listening to btrayfors' and Maine
Sail's advice: they're knowledgeable and have the hearts of teachers. I've benefited tremendously from reading them the last 5 years.