Questiona about a dual battery setup for my diesel swap TJ

RustyAutoholicGuy

Diesel Wrangler Guy
Supporting Member
Joined
Aug 1, 2018
Messages
1,574
Location
Virginia
Hey TJers,

Trying to wrap up my diesel build and I'm trying figure out the electronics/battery setup. I'd like to dual battery setup so I can have one battery for the starter, winch, lift pump & lights and a smaller secondary battery for all my ECUs I'm now having to run, so the ECU for my TDI ECU and the TCU for my Ford 6r80. Having a dual battery setup would also assist with cold starts on the diesel engine when using the glow plugs as well.

In another thread I was reading someone recommend this:
Hellroaring Technologies BIC-95300B Battery Isolator/Combiner

Now I use to be an Optima guy, I'm actually still running the original Optima battery with a 2006 date code in my diesel Liberty and it doesn't seem to be stopping either which is incredible, but Odyssey seems the go to brand now. So the batteries I'm considering right now are these two:

Odyssey 34/78-PC1500DT - The main battery for the starter, winch and lift pump along with running all the lights
Odyssey PC680MJT - The secondary battery which will be the designated battery for the TDI ECU and Ford 6r80 TCU

I'm limited on space and the Right Hand Drive makes things interesting as well but I know I can fit the Odyssey PC680 in the other battery tray underneath my brake booster as well.

I realize most people wouldn't need this kind of setup but I've read from several people on TDI Swap Groups that sometimes the Bosch ECU struggles to work correctly when cranking because of drops in voltage. So my thought is if I could separate the voltage draw for the starter and winch from the ECUs it might make everything continue to work better.

Anyway let me know your thoughts, maybe this is overkill but I have some big trips planned for my TJ in the near future and I want this setup to be as bullet proof as possible.

Thanks
Grant