Thanks for the replies folks!

I guess my idea might work as planned as no one has poked fun at me yet. But you know what they say, the night is still young. ;)

I'm thinking of forgoing the 12v solar system, since the trailer will be in the shade when possible, rendering the 12v solar panel on the roof useless. I'll just make the 48v system a little beefier and use the factory converter to charge my 12v batteries. It won't be as efficient, (going from 48vDC to 120vAC back to 12vDC) but if I lose say 25% of the power in the process, my 12v needs only represent 10-15% of my total electrical usage, so it's not as bad as it sounds. 25% of 10% is only a 2.5% power loss - and I'm buying simplicity and economy with this small, planned inefficiency. Plus, I'll be able to dedicate more resources (time and money) to building an maintaining one robust 48v system with a battery bank of twice the capacity than initially planned. Do you think I would need to install a switch to disconnect the converter from unnecessarily depleting my battery reserves when not needed? Or would it be OK to leave the converter draw power as it sees fit from my 48v bank? I know there are 48v-12vDC/DC converters, but they are not true chargers and won't replenish my 12v batteries with a variable voltage charging profile they need to properly maintain them.

What would you guys think about 8, S-550 Rolls/Surrette batteries (428ah at 48v) rather than 8, GC-2s? Add a couple trailer mounted GC-2s for my 12v needs, recharged by a nice 4 stage progressive dynamics converter/charger powered through an AIMS 2000w PSW inverter/charger (note the charger is for the 48v battery bank) that will normally be used to power the TTs AC outlets. www.theinverterstore.com/2000-watt-pure-sine-inverter-charger-48-volt.html Of course those 8, S-550s will add another 488 lbs to the truck, putting it near its max payload capacity when everything else (including hitch weight) is tallied.

I will have a little EU2000 Honda genny for foul weather charging back-up, just in case. As small as it is, this little generator is powerful enough to run my planned 12,000 BTU heat pump (which only draws 560 watts for cooling and 600 watts for heating) with power to spare, through the AIMS inverter/charger. www.geinnovations.net/HSAC_Productline.html

Chip

Chip,

I built a portable rack system using a drywall lift and aluminum angle and tubing. I can lift the panels onto the truck top and roll them back as the race is on wheels. If we are staying more than a couple of weeks in one location I will take them off the roof and set the rack up towards the sun wit the proper angle to achieve maximum exposure. If we are staying short term I leave them on the truck and either use the motorcycles for transportation or I can disconnect the panels from the system at the truck. I always plan ahead if I will disconnect or reconnect the panels so that it is done during dusk or very early before sunrise so there is no power going thru them.

Here is link to our setup:

 http://s962.photobucket.com/user/mybigboomer/library/RV%20Solar%20System

Hope this helps 

Les

Chip,

Our batteries are in the front compartment of the 5er. I had considered putting them in the truck which can handle it but since most of the systems in the rig use 12v including the frig and furnace/ AC if we needed the truck we would disconnect the 12v which would turn everything off in the rig that needs it. Also some RV parks cannot handle our full rig in the same spot so although very very rarely we have to park it off site which would preclude using our 12v on board.

For us it is easier to disconnect the panels if they are on the truck.

Hope this helps.

Les

OK, here's the crude drawings I promised, so you can see what I'm talking about.



I'll do one of the interior framing with controller, inverter, battery and shelf placement another day, once I collect my thoughts.

Thanks for your comments and criticism. They have been very helpful.

Chip