I'm sure this has been covered elsewhere and maybe someone could redirect this question. I was out over New Years camping for a few days and my question on the thread above is how long does it take "typically" to recharge the camper battery/batteries from running the truck engine?? Was hitting low single digits where I was and of course using the furnace a bit more than usual along with lighting loads. I don't use my fridge in the winter.
Any help would be appreciated.
Craggy-
Each setup will be somewhat unique. If you are using the hookup to the truck the way FWC installs it then you know for sure you are charging at less than 30 amps or the fuse would blow. They also use 10 gauge wire in the hookup and you would want to figure out just how long that hookup is (from battery to battery) and then go off to a wire capacity table and find out what the limit of that is, I expect it will be somewhere around 15 amps.
If you take 15 amps as the limit then divide that into the current amp hour capacity of your house batteries and that will be about how long your truck would take to charge the house bank from full discharged. (of course for the longest life of your batteries you should not be using but about half the amp hour capacity, ie not discharging more than 50%. So to get a true answer to your question you would need to know the charge state of your house battery system, for instance.
That's a quick brush, you really have to pin down all the numbers as all those above are just estimates. and only part of the full picture.
And, of course if you are doing your isolation with a Voltage Sensing Relay and some really big wires and circuit breakers you might push through much more. Though then you will run up against your alternator's capacity, how much the truck itself is using, and just what sort of wiring capacity there is between your alternator and your truck's battery. My Ranger has a 170 amp alternator, but I doubt I can get more than 40-50 amps back to the house batteries. Assuming it's 40 amps and my 200 amp hour my house bank if fully discharged would take 5 hours of truck run time, or if it's only discharged to the ideal 50% discharged that would be 2.5 hours. Real world would be greater, that's an ideal and also assumes no appliances in the camper are using electricity while charging.
I'm setting up a Bogart Engineering TriMetric metering system in my Eagle. That monitors all the electric flow in or out of my House Bank. It will give me the capacity of the house bank as measured in use, current amp hours stored in the bank, amp hours input into the bank, and those taken out of the bank. And a bunch of other info on the performance of the system, far more than I likely will need except for troubleshooting purposes. Between that and a regular volt/amp meter I have that can check individual electric flow and voltages associated with each circuit and appliance I'll eventually be able to know for my Eagle fairly exactly how well the system is performing.
