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Correct method to battery relocation

EFI Wiring Fundamentals

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Discussion and questions related to the course Motorsport Wiring Fundamentals

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I was wondering what method you guys use or recommend for relocating the battery.

When I move the battery to the boot (trunk), I run the positive through a 200A circuit breaker and battery switch with a field cut, then to the starter motor. From there I run 2 cables to alternator charging post and to another 100A circuit breaker inside the car which powers supplies the vehicle power and ecu/relays equipment.

For the negative side I run a cable from the battery to the body close to the battery and from this point another cable directly to the block. I also star ground my ecu and coils to the block

I use minimum 0 B&S battery cable for both positive and grounds

is this the best method or could I be creating ground loops or other issues?

I tend to run 200A megafuses as my first line instead of a thermal breaker but this is usually in weather/vehicles that run hot enough in the backhalf of the vehicle due to weird exhaust routing (sound requirements in California) that the breaker gets overly hot, sometimes popping, when you don't want it to. Other than that its similar to how I route things.

The way you've laid it out makes sense Anthony, but your isolation system might not be working the way you would expect. If your isolation switch only cuts the rotor field supply to the alternator, its possible the alternator will be self-exciting by that stage (if the vehicle is running), and still supply current. If it's output is then run to the vehicle side of the isolation switch, it'll continue to supply the electrical system of the vehicle, and cause a load dump spike.

Thanks for the advice.

How would you recommend connecting the isolation switch?

do you recommend the method in my attachment?

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