So I've recently purchased a 2007 Chevy Express Passenger van 3500 with the 6.0. I'll be using it for camping and lake days. I already own a pair of 100w solar panels, charge controller, pair of 6v CG2 batteries and a 1000w pure sine wave inverter. It all works great, I use it for mobile power here and there (almost never).
That being said, I plan to add the above setup to the van for extended off grid use and I see two realistic setups, both with their pro's and con's. Regardless I'll be mounting the two 6v batteries in a box along the driver frame rail, I'll be running them in series to attain the 12v. Overall my goal is to never have a dead starting battery, nor make the wiring too complex (I'm nowhere near intimidated of it, just don't want to do more work than required).
In a general sense it comes down to either running the two in conjunction with the original starting battery, which adds to the overall capacity, but then I have to worry about draining all batteries to the point of not being able to start the vehicle. Solution at that point is the "priority start" (shuts down all vehicle power at 11.7v saving enough to start the car) - http://www.prioritystart.com/12vpromax.php
That product seems very well reviewed on amazon, I'd essentially have to just ensure all of my power was pulled from downstream of that, i.e. I couldn't hook an inverter direct to the dual 6v setup or it would be able to bypass the shut down.
Option B is to basically treat them as two different battery systems, I'd use the blue sea systems automatic charging relay - http://www.amazon.com/gp/product/B000OTIPDQ?psc=1&redirect=true&ref_=ox_sc_act_title_4&smid=ATVPDKIKX0DER
It would allow both battery banks to combine for charging but immediately disconnect them during discharge, thus never allowing my starting battery to discharge from me using the inverter etc. This gives me the most "guarantee" of not draining my battery, but also makes the wiring much more complex, I'd have to make sure certain things were connected to the bank, others connected to the original car battery etc.
My initial thought is to simply add them to the original system, use the Priority Start and not worry about it. It'll take a hell of a lot of inverter usage to drain roughly 300AH at 12v while also having 200w worth of solar. I'm not out there running a hair dryer all day, I'm basically talking about running a blender, watching some TV etc. Even if I drained them, it would cut off at 11.7 and I'd still be able to fire up the van.
Thoughts?
