The general opinion on these forums is that the original equipment Parallax converter should be replaced with a multistage converter. On the other hand, here is a quote from the Parallax website:
Q: Does my Converter/Charger completely shut-off when the battery reaches full charge?
A: When the battery reaches full charge, its internal resistance will stop, or resist the current being provided by the converter and current entering the battery is between 20 and 25 milliamps. Fully charged batteries will self-discharge themselves and will always accept some small amount of current to offset this self-discharge
They then go on to say:
Q: Can I leave my Parallax converter system constantly connected to 120VAC power? Will this damage my batteries?
A: Parallax converter models deliver a nominal "float voltage" output of 13.2 -13.8 volts DC. Leaving the RV connected to 120VAC and the converter output connected to the battery should present no problems as long as this "float voltage" is between 13.2 - 14.1 volts DC and recommended battery maintenance is performed.
(Does that mean constantly refilling battery water?)
Q: My friend has a "smart charge controller" that plugs into his converter system. Why hasn't Parallax offered a "smart" charger option for my unit?
A: The issue we have with "smart charger technology" (when used in an RV) lies more with the application of the technology than the technology itself. In a typical RV 12 volt
electrical system, the converter/charger and the battery or battery bank is connected in parallel with the rest of the 12 volt
distribution system. In "parallel" means where the charging source (converter/charger) positive and negative output is electrically connected to both the battery bank positive and negative, and the 12-volt distribution system positive and negative, at the same time. The voltage output of the converter "smart charger" is based on a "detected" battery voltage. The converter "smart charger" claims to "monitor" and respond to battery condition while connected to the entire 12 volt
system. Unless the charging source (converter) has a separate or isolated charging output, we do not agree that a converter or charger can effectively differentiate requirements of the batteries from other 12 volt loads while simultaneously connected to the rest of the 12 volt distribution system in the RV.
Detected use or voltage change on the RV 12-volt load system (i.e. lights, pumps, etc. being turnedon) generally keeps these devices at a 13.6 -13.8 "float" voltage. This raises the question whether any real additional benefit is being provided to the battery bank unless the coach remains in a "non-use" storage condition. If a converter "smart charger" is only connected to the battery bank and can therefore monitor only battery voltage or current, and is not also connected "in parallel" with the 12 volt distribution system, we have no problem with the application of "smart charger technology".
So I'm confused. Is Parallax blowing smoke? Or can I sleep at night and not worry about my batteries without changing out the converter?