You don't want a charger
, you want a battery combiner or similar. Your shore/generator power has its own switch to select which one is supplying power to your boat. You almost certainly have a shore power
charger driven by shorepower or your genset. Today, these typically have two DC outputs- connect one to the house bank and another to the starting battery.
Finally you have to deal with your solar
DC outputs. If you simply connect them to both battery banks you face the risk of running down your house and start battery while on the hook (because they are both connected together) and being unable to start your engine
So wire the alternator and solar
panel output (from a controller, right?) to the house battery. Then you need something to pass the charge on to your start battery. Combiners, ACRs, Echo Chargers, Duo Chargers all do this. Yanmdina at www.yandina.com
has inexpensive combiners.
And with all due respect, from the nature of your question you need a marine
electrician to do all of this for you.