Cool ideas for AUX battery?

[davepl]

I don't want to deviate from stock wiring TOO much, but I've got the TP2 AUX battery option and I don't plan on camping.

From the schematic it looks like the batteries are connected in parallel when the relay at the AUX battery receives power (IGN UNFUSED). If that's active during cranking then I don't understand why the aux battery doesn't get involved with the cranking, but there sure isn't enough cable gauge to carry that kind of load.

I could wire it up like my boat, with a 1/2/ALL switch and an isolator so they both charge, but it'd be easier just to carry a set of cables and boost myself if ever needed.

So besides carrying around a charged battery, any good ideas? No stereo, no fancy lighting other than HID and cab lights.

How hard would it be to wire it such that the dome, headlights and park lights are on the AUX battery so that if left on they don't run down the main?

[Dunenutt]

My PS battery starts the truck, The DS battery runs everything else. If I run the lights and battery at shows, it still starts. I have an RV isolator.

[davepl]

Schematic!

I have a 120A Warn isolator right here. But when running the two batteries (in factory config) they are connected in parallel anyway, so they'd both charge, right?

It also disconnects when IGN is off, so I'm not sure what I'd use the isolator for. On my boat I have an isolator so that the battery that's not connected gets charged, but in the trucks they're always connected when running.

I could certainly steal your idea of running the lights off the AUX battery, but how did you go about that? Did you re-route stuff from the engine-bay side of the fusebox?

[Dunenutt]

I installed it like that when I was installing the painless harness. I have a junction block on the DS that all accy wires go to. The DS battery cable goes to it. The pass side batt goes directly to the starter. Alt wire goes to isolator, then out to each batt.

[DeadheadNM]

I have TP2 aux batteries setups and running a LH battery in both my K5 and K20 - I was of the understanding that wired correctly as per the GM schematic the RH battery was isolated such that lights etc. are powered off the LH battery saving the RH for starting the motor.

[flykelley]

If I remember from my days at the plant when you have the TP2 option the second battery will get charged but its not hooked into the main wiring. Its for running other large draw items you would add like plows, to power a winch and not kill the battery you use for starting they truck. In a nutshell it gets charging power but if your main battery dies it will not crank the truck. You need jumper cables and you can give yourself a jump. Been there and done that more than once.


Mike

[jjzepplin]

I ran mine to a furd relay and both batts start the truck. I have an isolater so both charge.
No need to carry cables.
I also have a furd relay on the main starter so there are two wired together.
Thing starts awesome!