The reason for doing this includes (But is not limited to)
1. the solar controller has temperature compensation (with a temperature sensor that hooks to the battery) which the converter does not have.
2. the solar controller is a four stage charger (the converter only has one or two - still trying to figure that out with this older converter)
3. The voltage regulation on the converter leaves a bit to be desired, as I have measured it as high as 15 volts then a few seconds later down to 13.4
Update - Just got an email from Morning Star. They say:
The PS-30 is rated for up to 30A of charge current. Provided the total combined charge current of the solar panel and 110V AC does not exceed 30A, then both can be connected to the PS solar terminals in parallel without issue. However, if the total potential current(amps) does indeed exceed 30A, the AC-DC converter should be wired directly to the battery.
