How to wire rectifier to charge spare battery?

[Toyextuh]

Hello, as stated. I want to run a spare battery when at idle so I'm not using the main battery. I want to be able to charge the spare when the boat is in motion but I dont know how to wire the rectifier, is this possible? Perhaps maybe running a solar panel is easier?

 

[mikidymac]

These do not use an alternator like an automotive engine. They barely make enough power to keep a good battery topped off and will not charge a depleted extra battery. Your best bet would be to have a separate deep cycle battery for your accessories and charge it every night.

 

[Toyextuh]

Thank you for your reply. I'm new to the boating game. What charges our batteries when the boat is running? Is it the rectifier?

 

[mikidymac]

The stator and rectifier charge the battery but it is a very low output system.