did you find these at a junkyard, or just buy them new from ford?

i'm wondering if it would be easier to just make a box for both extra batteries
out of 10 Gauge stainless, make up the terminals, lift the whole assembly
up in place on the drivers side, bolt it in, then run the cables over
across the groove in the underside of the transmission crossmember?

i was going to run + and - both across the crossmember, as i want
everything grounded at one single point, not on each frame rail.
i wasn't gonna bother with a battery isolator, just put a 300 amp
fuse on the crossover cable, near the OEM battery location, in case
of a nasty short. my main concern is having 4 65-PC1750 Oddesy
batteries in parallell, and having them go to ground. HCA is 1,350
per battery, and short circuit amps is in excess of 5,000 amps per
battery. that'll vaporize any conductor i could bolt to them. fault
current is somewhere between 5,300 and 20,000 amps. that will
vaporize a 900 MCM diesel locomotive cable. the OEM cable to the
alternator would just fuse if shorted, but heavy cable will burn.
i'm going to use 4/0 cable with crimped lugs and cold shrink tube
on the crimps to make good connections.

i'm not really worried about killing the batteries, and if i did discharge
all of them flat dead, i could pull the 300 amp fuse, and be able to
revive the two main batteries, and then charge up and reconnect the
other two later on.

so, junkyard, ford, or make my own? your suggestions would be
appreciated.

 

I had to make a backer plate anyway (which I did from old stainless plate). Saying that, I would probably just make the boxes myself if I were to do it over again.

The boxes were somewhat of a pain.

As to the main reason for the switch (sorry JR2980 for such a late reply), was so that when I go to remove the spare batteries, I can assure myself that I have no power at the hot terminal on the wire from the equipment under the hood. I also will run most of my time w/ the switch off and will open it up to charge the batteries every month or so.

 

thanks... i'll make my own.... the good thing about making a
single box with divider is that i can make up the cables tight
and put the whole thing in at one shot, then hooking up the
cables... the bad thing is you won't be able to do it without a
floor jack...

now, i found this place, that has feed thru battery terminals up to 4/0...
they have all the configurations of lugs needed for fabricating this

Catalog

and i have a 6 ton cable hypress... so i can swage all the connections.
onward.... maybe the end of this coming week if i've got a day or so off
to work on it.