Split Charging Batteries

[LostPiker]

My boat only has one battery. I'd like to add a leasure battery and a split charge relay. The engine is a 2 stroke yamaha 60hp outboard, do you know what sort of amperage the outboard will be kicking out and so what amperage relay I need?

[Andy135]

My strong recommendation is that you invest in a Blue Sea Mini Add a Battery kit (https://www.cactusnav.com/bluesea-mini-battery-p-15255.html). It takes alternator outputs up to 65A which is more than enough. For context, my Suzuki DF300 alternator puts out 54A.

The Add A Battery kit is a fit and forget solution to battery charge management and also allows battery isolation and combination with an On/Off/Combine switch. I fitted one to my Predator 165 and it was a simple install with the instructions they provide.

[suzook12]

quick search shows the Yam as having a 16A alternator. Depending what you want to run from the 2nd battery, you could use more common cheaper components as the charge is much less......