well guy's after much looking here is what i found.
Adding an Auxiliary Battery
Where in the heck did you find the room to mount a second battery?
I removed the stock windshield washer/coolant tank and cut the tank apart between the two separate compartments. I discarded the washer fluid tank and kept the coolant tank. I then mounted the coolant tank to the Explorers fuel tank vent, which has two round plastic caps on top of it. The coolant tank is now attached to the vent housing with a piece of perforated metal strapping.
With the coolant tank relocated, there is plenty of room for a second Optima battery. I mounted a steel battery tray to the inner fender using a block of wood as a spacer to hold the tray level. The wood is bolted to the metal ledge and the tray is attached to the wood block.
I replaced the stock washer fluid tank with the smallest tank I could find at a junkyard (I think it was out of an old Dodge). I mounted it next to the master cylinder, towards the fender.
The second battery is charged using a continuous duty solenoid as the isolation device. With the three position switch mounted on the dash I can charge both batteries, isolate the auxiliary battery, or jump start myself.