This thread
and
this long thread,
this thread and
this website should give you some help.
For what it's worth, I have had PD converters with the Charge Wizard in my last two trailers and would not have anything else. They have been reliable, well working units. :) My trailer stays plugged in almost 24/7 for 8+ months of the year and we have had no battery problems and our batteries have lasted about 7+ years each time. I just replaced the batteries in our present trailer that have been in there since new in 2004.
Barney