Battery charging via outboard w. alternator

[TY375]

I've got a TY with very little in the way of electrics (battery, running lights and radio). I also have a 5 hp Merc outboard with an alternator that connects to the battery to keep it charged. The wires from the alternator just connect directly to the battery posts. I'm planning on adding some lights to the cabin (my daughter prefers to read rather than pull strings or steer), so may increase the drain on the battery somewhat.

The question is, should I have some kind of a voltage regulator in there somewhere to stop the charging if the battery doesn't need it? I don't know what kind of charge the alternator puts out but believe it is small, but then so is my battery drain at least for now. The most testing I've done on the battery is to occasionally check it with a multi-meter to see how many volts it shows.

If not a voltage regulator, should I have something else in the line to make sure the current only flows from the alternator to the battery & not vice versa?

Thanks in advance for the expertise!
John

[Mark Yashinsky]

The Mercury should have a basic, internal regulator in the alternator. Look at the owners manual.
With that said, dont get fancy on the battery it charges or start trying to add batteries. Its a BASIC INTERNAL REGULATOR and not smart in any way, shape or form. The owner's manual should say how much power teh alternator itself, can put out, so keep your drain well under that, and your battery will be happy.

[WaywardWind]

The output of an outboard alternator is pretty low, especially so if the motor is running at something less than full rated horsepower. The alternators are designed for low charge rates for use on small boats where the engine is running all the time and at near max horsepower. Putting a regulator in the system would be fixing a problem the system doesn't have.