We're in the process of having a custom teardrop made by Minnesota Teardrops http://www.vistabule.com . We've lived and cruised on our sailboat for 10 years with 900 amps of Trojan T-105's and didn't want to sacrifice any of our electrical niceities on the teardrop. The only way to achieve that was to go with a LiFePO4 Lithium Ion battery bank on the teardrop. We purchased 2-100 amp hour LiFePO4 batteries along with all the goodies to satisfy our needs (1,500 watt pure sine inverter, battery monitor system, 40 amp charger, 200 watts of solar panels, etc.). I believe that with my research the trailer electrical system is completely worked out. It may even be the most advanced electrical system of any teardrop in existance (for the time being)
That leads me to the remaining unknown,,,, tow vehicle charging.
We'll be using a Jeep Wrangler as the tow vehicle and wanted to charge the LiFePO4 batteries while driving. It's my understanding that all 'charge while towing' systems are hindered by 12 volt line loss causing meger charge amperage as the voltage needs to be more than the battery it's charging for current flow. Because of this I was thinking of installing a dedicated wiring harness consisting of red & black 4 AWG copper battery cables to a plug at the back of the Jeep wired directly from the battery. The manufacturer of the batteries has told me that it shouldn't be a problem provided that the cables don't get hot. I wouldn't think that would happen with the 50 feet of #4AWG battery cables. I could also step up to #2 AWG instead of the #4 as a kind of 'chicken soup' concept. I'll also be adding a large fuse and battery isolator solenoid to protect the charge battery.
(as a note: The 200 amp hour LiFePO4 lithium Ion battery bank will accept 60 amps (or more) charging with no problem.)
Anyone have any input on using the system I've outlined above?
Any help is greatly appreciated.
Dan