Alternator Inverter Battery

[Hawkshaw1]

I have a question about my 2001 Mainship. The engine alternator charges the main two 8D batteries but does not charge the separate inverter battery (also an 8D).
That battery is only charged by the inverter\charger when on shore power or when running the generator.

The inverter battery powers the bow thruster and the windlass, in addition to the inverter.

Is it simple or difficult to modify the wiring to allow the alternator to charge the inverter battery too?


Thanks
Hawk

 

[tiltrider1]

It’s not particularly difficult but a complete review of your electrical system is required to do it correctly.

 

[DavidM]

It’s not particularly difficult but a complete review of your electrical system is required to do it correctly.

Including:

Proper sizing of additional wire
Fusing of same
Switching and/or isolation to prevent one load from running down all batteries

David

 

[Cold Duck]

Mine is simple, a perko switch so you charge one or the other. Can run inverter on either bank. But I have a separate group 24 battery for thruster with it's own pattery charger all located at thruster that runs off inverter or shore power. If you want to charge both banks at same time get an isolator is the easy way.

 

[backinblue]

My boat has one of these:

https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A

Lots of good technical and wiring information on the BlueSea website would be worth reviewing as a start.

 

[Lepke]

When I was a commercial fisherman, it was common to use a HD switch to switch in other batteries. It's best if they're the same rating and age but it didn't seem to hurt the lifespan.
After starting and the engines were up to speed, I switched the other batteries on.
No issues.

 

[jbbmillar]

Battery Combiner

I've used these for years: https://smartshoremarine.com/products/combiner-100. Simple, easy, not that expensive.

I think they sell them at a discount at Defender.com