Yes they do charge. Pretty much all outboards that have an electric start will re-charge the battery as it runs. Deep cycle batteries are more for things like trolling motors and pumps. The motor is (usually) ran from a cranking battery.Click to see full answer. Similarly, you may ask, how does boat motor charge battery?How does a outboard charge battery. Outboards use a stator instead of an alternator. When the engine is running, magnets on the flywheel spin around a stator, a do-hickey that consists of coils of wire and other stuff. This generates electromagnetic fields that eventually generate your charging current.Also, will outboard run without battery? Most electronic fuel injected outboards (including my Yamaha F225, and former F115) will not run without a battery connection (in fact, they won’t run on a highly discharded battery). I presume carbed engines will run if pull started and not connected to a battery. Consequently, do outboard motors have alternators? Do Outboards Have Alternators & Do They Charge Batteries? Yes. Almost all outboards that have electric start and that were built in the last 20 years, will have either an alternator or a stater that charges the battery when the engine is running. At what capacities and loads they charge the batteries is another thing.How do I keep my boat battery charged? In addition to charging your battery, there are a few other steps you can take to keep your battery happy and healthy: If using more than one battery in a bank, don’t mix battery types, or old and new ones. Keep your batteries clean and store them in a cool, dry place during the off-season. Check for corrosion.