Ctmaybury,
Yes the Suburban came factory with two batteries, but I am planning on only going back with one. The main driver for this was weight savings. (Yes my friends think I’m nuts.) The concern with this as you alluded to would be excessive voltage drop when the starter and other accessories pull large amounts of current. I did consider this and to compensate, I went back with a gear reduction starter versus the stock direct drive(lower current draw), am using an odyssey AGM battery which has very low internal resistance, and am using very large battery and ground cables (1/0 and 4/0 versus 4ga stock) with much lower resistance. With these modifications the starter should draw less and see less voltage drop so I don’t think starting will be a problem. Also since I will be manually controlling the glow plugs, I don’t plan on using them while I start, instead I plan on using them right before I start (like I do on my diesel tractor). And if it doesn’t work I can always add another battery.
Yes it is an interesting spot for the battery, and wasn’t my first choice. I wanted to relocate it out of the engine compartment and get the weight further back and lower down for better handling. I wanted to put it in the trunk, but that will cause issues later when I do some future planned modifications. My second choice was frame mounted, but it was too tall to fit where I wanted and would have been a maintenance and waterproofing headache. I wouldn’t normally suggest a battery inside the cabin due to off gassing, but this one is sealed AGM.
Cocyclist,
Thanks. I am trying hard to not to cobble it just to get it finished. That’s a good idea on the boost pack. I also have considered some assisting capacitors if it needs just a bit more oomph.
Edit:
Oh, and I appreciate all the feedback, it helps me make sure I haven't missed anything!