Second batt to auxiliaries question. (1 Viewer)

[JayDoc]

Firstly, let me apologize for the lack of knowledge I'll probably be displaying with this question but in an effort to not burn down my rig, I'd like to run a something by you fine folks.

In the near future I will be adding a second battery and I'm thinking of the simplest way to wire up auxiliaries in the console, cargo area, and rear rack lights.
I'd like to have usb outlets out of the console, 12v outlets x 2 in rear cargo area, and a set of LED work lights off the back of the roof rack.

Can I (safely) run hot wire from the second batt (with inline fuse) -----> toggle switch ----->fuse box (located in console) ----> (1)-------> usb outlet ----->usb outlet.
(2) ------> cargo 12v outlet -----> cargo 12v outlet.
(3) ------> toggle switch ------> rear roof rack LED lights.

I think 10ga wire would be acceptable for the usb and 12v outlets.
Would you use a different gauge for the LED lights?
What would you suggest for the lead wire?

Thanks for any advice.

 

[JayDoc]

FWIW; this will be in an 1983 FJ60 with smittybilt security console with some mods to accommodate the above electronic changes.

 

[mmajsw]

Depending on the amount of amps you will draw, you will need a bigger wire. 10 gauge is rated for 15A over 15' with a 3% voltage drop (12.5 V at battery about 12.1V at plugs). I used the chart at http://www.engineeringtoolbox.com/amps-wire-gauge-d_730.html for computations.
A better way would be to use the switch to trigger a continuous relay located after the fuse from the battery that would be rated for a greater number of amps than all your accessories will draw. You would probably have to use 6 or 4 gauge wire to carry the total amount of amps needed. That heavy wire would lead to a fuse box close to the location of your accessories and then run the individual wires you need to the various plugs/lights/ USB outlets. Remember that you always end up adding more later on so build some buffer into your setup.
A sample wiring diagram can be seen here http://www.yotatech.com/f131/wiring-switchable-aux-fuse-block-264922/

 

[JayDoc]

Thanks for the reply and the chart reference.
After your suggestion and reading a little more, I think I will add a relay (located in engine bay) powered off the ignition after the inline fuse.