I checked Centurians own information which states that it outputs constant 13.4 Volts this is a one stage poor trickle "charge", this is a con that goes on worldwide by the looks of it.
Here is what I use http://www.sterling-power.com/htm/ced.htm
People actually think an alternator is a battery charger too, but it suffers from the same problem lack of inteligent control. Thats why when I use the alternator to charge I use one of these
The one that Madjack as posted in his last post is a 3 stage Charger, the centurion is definately not any kind of staged charger, the WFC one is set to charge Gel etc I would prefer if it was set for lead acid (all stages would have higher voltage)
I know that sterling do the design work for an American company too and they both use the same manufacturing facility, but I cannot remember what Charles Sterling said the USA company was called.
Many chargers are called "automatic", but they only work like an alternator, ie after an initial inrusch of current the batteries internal resstance changes which considerably lowers the ampage thats drawn across, this is a function of Ohms law and is not any kind of "inteligent" change of charging parameter's. Many on this basis also claim to be 2 stage which is utter rot.
BTW the ones I have linked to work the world Over.
gotta get some grub catch you all soon