What I would like is a power supply to permanently wire into the RV's 12V circuit (in parallel with the stock Parallax 7345 converter) that was similar to the MEAN WELL RSP-1500-12 that not only had adjustable DC output voltage, but an adjustable DC output current limit as well.
Like MEX suggests, I'd just set it to 14.4 volts all the time - assuming that this wouldn't be too much voltage for the 12V items in our RV 24/7 - but set it's current limiter to around 35 amps. This way I could be forcing 35 amps into the AGM batteries drycamping whenever they would still accept up to 35 amps at 14.4 volts during recharging.
This would permit to make maximum use of my 650 watt Honda EX650 for battery charging when drycamping, but also have more than 35 12V DC amps available when using the Onan generator or when on hookups due to the MEAN WELL being in parallel with the 45 converter.
