by mskobier » Sun Jan 23, 2011 5:16 pm
Russ,
I just did a little research on your Honda EU2000 generator. The spec sheet says it will deliver 7.5-8 amps on the battery charge circuit. That should be plenty to keep up with your DC loads. When the batery finally reachs full charge, with the generator disconnected, it soould not drop more than about .5 volt when the furnace first starts up. Remember, when the motor first starts and the electronic ignitor is lighting the furnace, you are probably seeing a 5-10 amp load for those few seconds. After that, the current load should be about 3.5 amps while the fan motor is running. So the measured voltage should recover pretty quickly.
As for efficiency, as long as you are running other 120v ac items, then then it makes sense to run the generator. I would not run it just to charge the battery.
Is your truck wired to supply power to the trailer when it is being towed? If so, you can also place one of your batteries in the bed of your truck, strap it down some how, make up a pigtail to plug into your vehicle trailer wiring, and hook to the battery. That way, when you are driving to the library or running around town, you can be charging one of your batteries. All of the 7 blade RV trailer plug have a connection for a trailer battery charge circuit. Most that I have seen are set up to deliver about 30 amps to the trailer battery. Since the charge circuit is capable of large currents, you could completely recharge one of your batteries in just a couple of hours. Now, you really will not get 30 amps to the battery. The internal resistance of the wiring will limit it some. But if you are driving anyway, might as well take advantage of it.
Mitch