Questions on using dual alternators as separate systems - PowerStrokeNation : Ford Powerstroke Diesel Forum
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post #1 of 1 (permalink) Old 03-01-2014, 05:58 PM Thread Starter
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Questions on using dual alternators as separate systems

I have a 2002 F350 7.3L that has dual alternators. I've been researching how to install 2 6v batteries (in addition to the truck batteries) to run an inverter that I would use for power tools, compressor, etc... My original plan was to purchase a DC Power 270amp alternator and install it in the upper location and use a Blue Sea ACR (battery isolator) to separate the two battery banks. The problem with this is I read the PCM cycles between the two alternators so you never know which one is charging. Also, if I disconnect the lower alternator and one battery bank is discharged more than the other, do both banks get the same amount of volts/amps? Would this cook the batteries that weren't discharged as much?

Searching the internet, I came across some RVers that are using dual alternators as separate systems, meaning the upper alt. maintains the truck batteries and the lower alt. maintains the house (camper) batteries. I would like to use this method but have some questions:

Can I reverse the above method and use the lower alt. (stock 110amp) for the truck batts. and install the 270amp alt. in the upper location to charge the house batts?

I would like to use the truck batts. just for starting and wire the fuse box to the house batts. What are the pros and cons of this?

What's the best way to wire the lower alt. as the primary alt (switch the wires at the PCM or make a longer wire harness)?

I read somewhere that I need to disconnect the stock lower alt. wiring at the passenger side fender and put some kind of jumper wire there to fool the PCM that there's only 1 alt. present. Then, I need to wire a switch to the upper alt. exciter to energize it to start charging. Is this correct?

With this system, it doesn't seem like a battery isolator is needed anymore. A great function of the Blue Sea ACR is that it can combine both battery banks in case the start batts. need a jump. Is it possible to still use the ACR or is there another way to combine the batteries?

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