Naio wrote:
There is a 650 for sale near me! I could go try pulling on its rope . Do I understand correctly that it might put out 50 amps DC charging???
It's an outstanding coincidence that one happens to be available near you!
The EX650 would only be good for about 30 amps charging. That's assuming that you used it to power a charger to charge your RV battery that maintained around 14.4 volts on the battery's terminals during the initial charging stage (if the charger is a multi-stage charger).
Why do you need to use 50 amps to charge your batteries? I charge our large dual-battery RV battery bank all the time with only about 30 amps or less from the engine alternator when driving, or with only about 15 amps from the RV's converter in parallel with a cheap Sears 2-10-50 car battery charger when drycamping. When drycamping the EX650 powers both the converter and the Sears charger at the same time.
Remember that the little EX 650 runs for 4-6 hours on only 0.51 gallons of gas. I merely run it out of fuel each recharging cycle to "bring up" the battery bank when drycamping for several days in a row. When I drive to the next camping spot after camping, the engine alternator brings the RV battery bank back to full with 3-4 hours of driving. When I drive back home after camping, I plug in the RV at home and the converter brings the battery back to full within a day or two of continuously being plugged in.
I carry 2 gallons of spare fuel for the little Honda in a red colored all-steel safety rated gas container.
The Honda is so quiet, I can't hear it inside the RV, and outside it's sound is a low frequency sounding muffled hum that fades quickly a few feet away. It's sound is, to me, way more pleasing than the more mechanical sound of the plastic-cased modern inverter Honda generators .... and certainly more of a pleasing "white noise" than hearing the up/down changing RPM of inverter generators.
Our EX650 is at least 25 years old. A few years ago I replaced one of it's circuit breakers that I bought over the Internet. We carry it in the RV all the time for drycamp battery charging and as an emergency backup to the built-in generator ... and would do so even if we had solar.
All of the above is very simple non-rocket science. Our last RV battery bank lasted about 8 1/2 years treating it this way, and I'm not sure those batteries were real bad when I traded them in last month. However there may be one caveat to our RV battery charging procedures ... our RV batteries are of the AGM type ... which charge quicker - with any particular charging method - than wet cell batteries do.