I am sorry if this is a dumb question, but we plan to tow a camping trailer with our F150 PB with 7.2kW generator. Can it charge the camper batteries while we are driving? Or, does it need to be stationary?
I would appreciate any clarifications, pluses and minuses. Thank you!
That is an excellent point! The trailer SHOULD have a full relay built in such that if plugged into shore power, it charges the trailer battery off the 120V-AC => 13.4V-DC converter, and physically isolate the trailer 7-pin battery line from the truck. I do this all the time in my street, I leave the trailer hitched and plugged to the truck 7-pin, and I plug 120V AC in to my house to pre-cool the fridges overnight.
Perhaps older trailers do not have the proper isolation between the trailer's converter and 7-pin charge line, which would likely blow a fuse?
Yes, you should use a VSR (Voltage Sensing Relay) in the trailer. it allows the trucks 12V to connect to the trailer only when the truck is running. when truck is off, the VSR disconnects the 12V. otherwise you risk draining the truck's battery while sitting. When connected to 120VAC, my trailer's onboard charger not only charges the trailer batteries, but the VSR allows connection to the truck's battery and charges it too. But yes, it is a 4-stage smart charger so it regulates the charging, depending on a dead battery versus just a trickle charge level.
Now maybe some people here can tell me if the "modern" F150 has something similar already built into their tow wiring circuits? I heard that the 12V Aux on the plug is not powered unless the truck "senses" that a trailer is connected. but does this same capability protect your truck battery when trailer is left connected with the truck off? My dealer was useless, with no answers.
