I was in the same position as you when I bought my boat -- a excellent low-speed generator but no inverter.
I lived with it like that for a couple of years, then installed a Victron charger-inverter when the Newmar charger
Here are my observations:
1. An inverter is extremely useful even on a boat with a good, quiet genset. The reason is this -- you don't want to start up the genset every time you put a kettle on, make a piece of toast, watch a DVD
, run a vacuum cleaner for two minutes, charge a cell phone
, etc., etc., etc., etc., etc. It's not good for the generator to run it for short periods, under light loads, stop and go, etc., and besides that even a quiet genset does make some sound. So you want to concentrate your power production in intensive generator runs once or twice a day. So the inverter is tremendously useful for efficient use of your genset.
2. Victron is supposed to make the best charger/inverters; certainly they are the most expensive. The functions are wonderful; and the units themselves feel like good quality -- heavy, robust-seeming kit -- using transformers, not switch-mode gear
. But I have had a lot of trouble with all of my Victron gear
, including a dead failure of the charger inverter at a little over one year old. I would not necessarily recommend it. Do look for one, however, that has something like Victron's "power boost" feature; it is extremely useful.
3. Beware of power ratings. My inverters says "3000" on the tin. Does it produce 3000watts? Hah! If you read the fine print, it's really 2500 watts. Derate it from there for temperatures above 20C. Derate it more if you don't have battery
capacity to maintain 26+ volts under load. So in reality, although I am in a cold climate and with a large, fresh battery bank, I certainly cannot run anything over 2000 watts with my "3000" inverter without getting an "overload" warning. Comfortable "working load" for my "3000" inverter is probably more like 1600 watts. The good news is that this is probably all you need -- it's enough to run any one thing at a time, and if you need more than that, then you should be using the genset anyway.
4. The exception to that is the electric
kettle. I have not been able to find one that uses less than 2.3kW. I do run my kettle off the inverter, which complains of being overloaded (although the load at this temp and voltage should be ok according to the specs). But I am still looking for a kettle with a smaller element -- 1.5kW would be ideal. An electric
kettle is an extremely useful thing to have on board, by the way, especially if you have tea drinkers on board.
5. Having an inverter on board greatly increases the demand for battery capacity. If you don't have a big bank, or are willing to upgrade your battery bank, then you might think twice about it, or else buy a small one for just small power things like electronics
. I have 420 amp/hours x 24 volts -- that's just about enough. Any less and I would have to seriously curtail use of the inverter.
Good luck, and let us know how it all turns out.