OK, the manufacturers of portable generators have instructed their Dealers not to answer questions related to the use of the generators in boats. Their attorneys are quite adamant about the possible liabilities for an accident involving the generators, whether it be, CO poisoning, electrocution, fire, explosion or damages to expensive instrumentation. Now your question is whether a 2, 200 Watts will charge your battery bank, the answer is yes if it is used to power an inboard charger. Some generators have a 12V DC outlet but they do not do a very good job in charging batteries, more to use to plug in 12V fixtures.