Renogy DC Battery Charger - Alternator Wiring

[siraXLe]

Hi,

I am wiring this system https://www.mobile-solarpower.com/simplified-400-watt-fewer-wires-and-alternator-charging.html and am having trouble with the alternator output wire.

Should the alternator output be wired to the DC Battery Charger Alt+ terminal or should the alternator output be wired to the starter battery / bus and the Alt+ from the charger wired to the starter battery?

Any assistance is appreciated

 

[TacomaJoe]

I will assume that you want to add the system to a vehicle or RV. The original wiring stays the same (Alt+ goes to starter battery). You will add a new wire between the Renogy and the starter battery + post.

 

[siraXLe]

It is being added to a yacht. Originallly the Alternator output was wired to a bus. Should I rewire this to the starter battery and then another wire from the DC Charger Alt+ to the starter? How does the DC Charger know what the alternator is outputting and when battery capacity is reached?

 

[TacomaJoe]

Basics: The job of the DC charger is to charge the LiFePO4 battery. It will use the solar input and/or the Alternator power to do the charging. A LiFePO4 battery can take a heap of power and will suck more than your alternator can provide without burning up so the DC charger limits how much will be pulled from the allternator to protectect it. The connection from the DC charger to the alternator can be to the Alt+, the bus or the battery terminal.

 

[siraXLe]

I don't think I fully understand. Is this how it is meant to be setup
The Renogy Alt+ is wired to the starter battery + terminal
The engine alternator output is also wired to the starter battery + terminal

Is that right?

 

[BobR]

Your alternator output can be wired to the buss bar if the buss is connected to the battery + positive.
You do not want a switch between the alternator and the battery (load).
If the load is suddenly disconnected from a running alternator bad things happen (voltage spike).

 

[BobR]

The DC-DC charger can also be connected to the positive + buss bar.

 

[BobR]

You will find some good information here: https://nordkyndesign.com/featured-articles/

 

[Goboatingnow]

The renology unit assumes the starter battery is connected to the alternator. In the normal way.