Basic but good quality and reliable solar system design

[Mwilliamshs]

32 vs. 36? No idea, I simply went with what AM Solar sells.

I was staring at trees and missed the forest. # of cells isn't worth worrying over, voltage is voltage.

I think that you will find that your alternator is the fastest charger that you have. As you noted, however, the charge rate tapers off and, as I stressed, the last 50Ah or so can be hard. 6v camper batteries are way too large to go under the hood. Mine are at the frame level, but rather further back than I would like. I run 2x1/0 cables which is grossly 200A over a 40 foot round trip. That is 100mm2 of copper. I would not go smaller.

Cabling sounds spot on. I will go as far forward with my house batteries as possible. I wouldn't put them in the engine bay even if they'd fit; these vans are notoriously hot under the bonnet. Frame rail mounts are convenient for saving interior space and putting the weight down low but the batteries or their mounts are always filthy and thus hard to maintain and always in the elements which isn't ideal for long life and must hinder charging in cold conditions when the van is heated. I have even toyed with the idea of a vanagon style box under the passenger seat. Ford van seats sit on a pedestal that resembles a piece of 6" steel pipe standing vertical with flat flanges on each end. I think a box with length equal to the pedestal (seat height stays the same) but of sufficient width to house the two 6v batteries (under 15" total width even with .5" between them) [still narrower than the seat] would be SLICK. They would be up front for short cables, down low for CoG, up front is a good place for their 124 pounds, and since VW has been doing this for years I think a safe, secure system could be devised (copied) quite easily. My mention of available underhood real estate was rhetorical. I'd only add a battery there if winching or some such load was anticipated, it's not. Alternator charging is the reason for my 130amp upgrade. Stock is 60-100 depending on options and the existing part, a 2G series, is a liability due to poor design (they leak smoke) so will be swapped out before the van is even driven much.

I would not bother to upside my starter battery, in fact, If I could, I would reverse the common logic. That is, I would attach the alternators directly to the camper batteries and simply have a small branch circuit to the starter battery. (Even discharged 50% my camper battery is still twice the size of my starter battery.) Can't do this because of vehicle warranties, etc., so I do the next best thing. I also recommend an intelligent relay and a manual override switch.

I agree with oversized start batteries as detrimental and plan to use a VSR (battery isolation relay that senses voltage and is "smart" about when to connect them) with a manual jumpstart feature.

Based on years freezing my ankles off on the Altiplano, I would urge that you pack long undies and have a good heating system. This from someone who didn't and watched the water freeze inside his tent. The two classic errors of overlanding are:

-- Selling your sand ladders after the Sahara. You need them for Congo mud.

-- Thinking that South America is warm, after months on the beach in Central America.

The Altiplano is bone chillingly cold. Ironically, it can be worse in summer as it is cloudy and rainy. The winter tends to be dry and sunny. You will learn why people worship the Inti Raymi. :Wow1:

If South America plans firm up cold weather equipment will definitely be included and coats and thermal undies are permanent fixtures in my camp gear. I think a propane stove is becoming more likely (re: our pm convo) so adding a heater will be as simple as plumbing it. I will add an engine coolant loop toward the rear for a hot water system and adding a rear cabin heater with that is just TOO cheap (zero extra hose) and TOO easy (2 hose clamps and 2 wires) to NOT add. Thanks for the info!