Email from Parallex Tech which is the old Magnatek:
"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. (To my knowledge) All of the RV "smart chargers" currently offered by anyone have a single output from the power supply that feeds the entire 12 DC system and none have a separate or isolated battery charger output whether they provide multiple positive and negative output terminals or not.
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 loads while simultaneously connected to the rest of the 12 volt distribution system in the RV. There are also 12 volt loads on the system that may not react well or could be damaged by the voltage imposed on the batteries (and thus the 12 volt system) while parallel connected. If using an external "smart charger" we recommend isolating the batteries from the 12 volt load system so that 12 volt system loads are not exposed to "equalization phase" elevated voltages etc.
If a converter "smart charger" is only connected to the battery bank and can therefore monitor only battery voltage and current, and is not also connected "in parallel" with the 12 volt distribution system, we have no issue with the operation or application of "smart charger technology".
We are soon to release an "upgrade" section for the 500, 6300, and 7300 series systems based on the 4400 series ParaMode circuit board that will be called the TCRU.
This upgrade unit will have a temperature sensor cable that would need to be run and connected to a battery negative post. The output converter output voltage will then be continuously adjusted based on the detected temperature at the sensor. This will provide a more appropriate "float" voltage to the battery system based on the voltage the battery needs for the temperature the batteries are experiencing. Maximum voltage to the 12 volt system and the batteries will be about 14.5 volts DC and minimum voltage will be around 12.5 volts DC making the system voltage safe for use with the other 12 volts loads on the 12 volt system.
This temperature compensated output voltage will not be affected by 12 volt load use or while the RV is in storage.
The upgrade will also have a 4 hour timed "boost" mode for faster recharge after initial power on.
The upgrade will replace the present converter section but cannot be added to the present converter section.
Look for more information on this upgrade to be added to our website at www.parallaxpower.com
in the near future. While the 7345RU upgrade is available now, I do not have a firm date at this time when the TCRU will be available for sale or what the price is slated to be. I know it should be soon."