Amp to battery or MDP

[Jmac572]

Seeing conflicting advice on this.... I have a 2004 390 Sundancer and adding a second amp, I currently have a Fusion 4 channel 1400 watt amplifier connected in place after we removed the factory garbage amp, I am adding a Fusion 5 channel 1600 watt amplifier as well... Do I have to wire directly all the way to the batteries? Or can I wire it to the 12 volt area at the main distribution panel in the salon? The sat TV, guest head, and both lower accessory switches are open right now, also made the switch to all LED cabin lighting so that saved about 15 amps... As of now I am planning on going to the batteries unless anyone with knowledge in this field/boat knows the factory wiring can handle the extra load.

 

[dtfeld]

Pull up your schematics. Looks to me like the MDP is fed through a 80A breaker in the bilge. That has to feed everything on the panel above.

Each of those amps will pull a max of 80 amps each, so 80 x 2 = 160 amps total.

To do it right, I would put new breakers in the Engine room (there are empty slots), and run good quality wire. For that load and length, you probably looking at #2, possibly 1/0. Thats for each amp.

 

[Jmac572]

Pull up your schematics. Looks to me like the MDP is fed through a 80A breaker in the bilge. That has to feed everything on the panel above.

View attachment 124844



Each of those amps will pull a max of 80 amps each, so 80 x 2 = 160 amps total.

View attachment 124845



To do it right, I would put new breakers in the Engine room (there are empty slots), and run good quality wire. For that load and length, you probably looking at #2, possibly 1/0. Thats for each amp.

View attachment 124846

sounds good, I’ll do that, very much appreciated for the detailed reply. I do know certain 12v systems are fed through the starboard bank and certain ones through the port bank so I am wondering if there’s two 80amp breakers…. Either way not enough for two amps, and come to think of it I believe there is a breaker switch labeled “amplifier” in the engine room for the factory amplifier we replaced.

 

[Craig]

I like these fuses for direct to battery connections. Protects the entire length of wire.

 

[dtfeld]

I like these fuses for direct to battery connections. Protects the entire length of wire.

View attachment 124853

I'm using those for a LiFePO4 battery build, they work great.

The come in a dual fuse config from Blue Sea Systems, and would be a good

option.

Only downside is they only come on 3/8" mount, and my old AGM batteries have a 5/16" post, so measure what your batteries are. Batteries with a 3/8" accessories post would be perfect.