Battery Bank setup for a Skoolie conversion (with PV to be added later)

Hi AlleyCat,

It sounds like you plan on having something broadly similar to my bus's PV installation.   I have eight grid-tie panels in two separate sets of four, each panel individually tiltable from 21 degrees down against the roof, to level, or to 21, 33 or 45 degrees up.   Each set of four panels is wired in parallel and feeds its own 60A charge controller that in turn charges its own set of four golfcart batteries wired in series and parallel, then the two battery banks' outputs feed through 250A Schottky diodes to a common DC load center that powers the inverter and house DC loads.   I use 4/0 and 2/0 for all my battery cables, and 4/0 to the inverter.   You really can't have too fat cables when dealing with large DC currents  -  if I could find 250MCM-size cable and lugs I would have used that instead!   It's important to crimp the lugs well when making cables for high currents:  the common hammer-type crimpers won't do a good enough job, so a set of good circumferential crimpers like the FTZ 94284 are well worth it.   NAWS is still the cheapest source of tinned 4/0 lugs, less than $2 each, and decent 4/0 welding cable is no more than $4 a foot from eBay, so it's really not much more cost to do it right the first time, instead of using too thin cable and then having voltage loss.   I use Blue Sea switches and VTE pass-throughs and fuse holders, good quality and reasonably priced.

Before you buy an AIMS inverter you may want to research them carefully first  -  some folk have had less than satisfactory experience with them.   There are other brands which may be better quality for not much more money.   NAWS sells good inverters  -  check them first.   Samlex/Cotek are decent-quality inexpensive inverters, especially their SA-series that can handle reactive loads better than other budget inverters.

I would suggest aiming for the ideal 13% upper charge rate for however many batteries you'll have, if only because bus roofs often are not oriented ideally compared to home installations, then you should be able to keep the batteries correctly charged even in winter or if parked at less than the ideal position to catch the sun.   My 2kW of panels will (theoretically) charge 900aH of batteries at about 13%.   I still have enough space for two tiltable water-heating panels which should provide my hot water most of the year without needing to use my propane water heater, and any excess power from the PV in the afternoons after the batteries are fully charged can be fed into the water heater's electric element instead of going to waste.   I will use electricity quite sparingly, so 900aH should be plenty, enough to normally only discharge the batteries to about 75% SOC after each night.   With careful use of electricity I should be able to last three days before reaching 50% SOC if the sun's not cooperating, at which point I'll use the emergencies-only generator to bulk-charge the batteries back up to 85% or so.   I plan on using one or two small chest freezers, one converted as a fridge and the other maybe as a freezer, and they will be powered by their own separate small inverter to minimize standby power consumption.

I looked at a few Thomas buses before I found my Crown.   I almost bought a 1989 Thomas WestCoastER, but was outbid by a church   -  that was a neat bus, with full air suspension and disk brakes.   What engine and transmission does your bus have?

John