Originally Posted by downunder
Would be useful to know what your loads would.
Northern lights, Onan, Westerbake are all good makes. I have noted numerous problems with the higher reving (3000rpm) sets such as Panda.
Sounds as if your are going for a smaller genset to run at 75-80% load for best engine life. The Vitron inverter charger
with boost will help with a smaller genset and allow for higher electric motor
Ensure it is low rev 1500/1800 - heavier but much more reliable.
If you can possibly fit it in your boat, definitely go with a 1500/1800 RPM genset -- the difference is night and day.
Northern Lights, Onan, and Kohler are all very good. They are simple, heavy, large displacement
, low-revving. As a result they are much quieter and much longer-lived and much more reliable. Go for a three-cylinder over a two-cylinder if you can -- the sound and vibration is more pleasant and less intrusive.
Avoid Fischer-Panda like the plague. It's the opposite approach -- a tiny, small displacement
engine screaming away at high revs inside a sound enclosure.
We have a 6.5kW Kohler on our boat. It has a 1,000cc three-cylinder Yanmar diesel
engine and is almost inaudible inside its own sound enclosure inside our sound-proofed engine room. We don't have air conditioning
(yet), but I would not hesitate to run the Kohler all night on a hot night to run air conditioning; you don't hear the genset and neighboring boat in the anchorage hear absolutely nothing.
When sizing your genset, consider using an inverter with "power boost" feature, like the Victrons. That way you don't have to size the genset for your startup loads (which can be very big if you have a lot of air conditioning). You can size the genset for the continuous loads, and the power boost will supply the short-term startup loads using inverted battery
power. You don't want your genset to be oversized, because:
1. It will be needlessly more expensive;
2. It will be needlessly larger, bulkier and heavier;
3. It will usually run with less load than it needs to be happy and healthy
4. It will usually run with less load than it needs for best efficiency