The Magnetek converter is a single stage converter. That is, it puts out a constant 13.8 volts, This is too low to charge a discharged battery fast, but is too high to maintain a fully charged battery.
The PD9245, that has been suggested, is a 3 stage converter. It starts out charging a discharged battery at 14.4v. After the battery is partially charged the voltage is reduced to 13.6v, and then later when the battery is fully charged it drops down to 13.2v to maintain the battery. I'm quoting the numbers from memory so I may be off a bit but you get the idea.
The PD9245 would be my choice.
Edit: just noticed I left a lot of "1"s off.
