Just recently I did a trip to Broughton Island & I took my Honda generator to charge the batteries . I'm pretty lucky that the generator fits under the front cast deck nicely - so its not in the way.
OK ….. running a generator while still remaining on board is crap - Even the quiet Honda is annoyingly loud - specially running it for 2 or 3 hours when sitting at anchor . The killer was the fumes - the boat points into the wind & the fumes come back into the cockpit area ….. so you end up tying off the stern.
The generator is fine if you are able to get off the boat when it's running .
I'm planning a trip up to a reasonably remote part of Qld coast next year …… & leccy charging is one of the big considerations but now I know what it's like when you remain on the boat - i'll make sure we can get ashore somewhere when charging.
Yes a portable generator will do the job - but you need to keep in mind what charge rate …… I have 2 x 25amp chargers hardwired - so I actually needed a 2KA generator as a 1 KVA would not provide the power required.
Chris