FWIW, the V10 in our motorhome idles very, very quietly ... quieter than our built-in Onan generator or portable Honda generator.
I've lately started merely idling the V10 in our Class C to bulk-charge the coach batteries when drycamped on RV trips. It's alternator dumps up to 70+ amps into the 50% discharged coach batteries and tapers down from there throughout the idle-charging period.
I actually learned of the above charging approach from my father-in-law around 45 years ago when he did it with his GMC V8 powered motorhome, but have only been doing it recently when I realized how quiet the V10 idles.
