Charging Battery with Generator

Keep in mind that a few days with only "pump and lights" won't require much charging. Even if you throw LP fridge in.

In my trailer the pump, lights and thermostat of LP fridge draw 25-30 AH. A pair of 6V batts with usable charge 112 AH will last 3-4 days before they drop to 50%.

In this particular case having the wfco converter may work in your favor. Since it is unlikely to go to boost mode it will not put as much load on the genny.

Does the generator have a 12 volt outlet? If so, that may be used 'in a pinch' to get the battery bank up to a level where the converter won't overload the genny.

I would test at home myself.

Plug the shore power cord into the generator and see what happens. Worst case it will trip the breaker on the generator. Make sure to switch your refrigerator to propane and turn off anything that would use power when plugged in.

Edit: Mex beat me to draw.

It would not be prudent to "assume" anything...

AT HOME NEAR A SHORE POWER SOCKET...

Disconnect shore power

Discharge your batteries to 12.0 volts by turning on all lights. This means 12.0 volts, AFTER you shut the lights off, wait one hour then verify voltage.

Start your inverter generator. Let it warm up.

make sure your refrigerator can switch to gas. Turn water heater selector to gas.

Plug in the shore power cord to the inverter generator.

Either it can power your converter or it won't. You'll be the first to know. At least you will be home where, if things turn out to be a surprise, you will have options. In a campsite, the number of options markedly decrease.

kohai wrote:
I go with simplicity and just plug my honda into the rv and let it do its thing.

Which is great as long as your RV's "thing" doesn't require more power than your Honda can put out. You probably have a 2000W Honda, which is more than plenty for 99.9 percent of the converters out there.

With the OP's 800W generator, he is VERY limited on how much "thing" his RV can do before he pops the breaker on the generator.

I go with simplicity and just plug my honda into the rv and let it do its thing.

First problem - it looks like you have a WFCO converter. These are known for NOT going into Boost mode when charging.
Second problem - you probably have 8ga wire from the converter to the battery. That results in too much voltage drop for good charging.

I'd go with using a good battery charger directly connected to the batteries.

A quick google for the owner's manual for your trailer says your converter will draw 8 amps. I suspect that's average so quite a bit more when it's first turned on charging depleted batteries. I don't think it will work with your tiny generator.

As has been suggested, get an external charger with current limiting.

As an aside, read the fine print on your generator / inverter: is it 800W CONTINUOUS?

800 watts is good for about 30 amps into the battery. A good chance the converter will overload the generator with a low battery. Use the portable assuming it is 15 to 30 amps output. Just connect it on the battery direct, no need to remove anything.

Once voltage gets up in the 14.2+ range continue for one more hour.
Most likely the converter would quickly taper to a trickle charge at 13.6 volts.

Give it all a test before you go.

You need to have a way to charge the battery without overloading the generator. More specifically, you need to keep the charging current limited to approximately 30 amps. Even if not horribly discharged, the battery will probably pull more than that in the first few minutes of charging. One approach is to just use a charger rated at maybe 25 amps maximum, or one that allows you to control the output. If you want to use the power converter, posting the make and model might get some feedback on how well it may or may not work with the small generator. This all assumes you'll be at a fairly low altitude. At a few thousand feet the generator performance goes down. Best to test it all out at home first.

I use an 800 watt Earthquake/PortaSource inverter generator, with two ways to prevent overloading it. One is to use a larger generator for the initial charge, then switch to the small generator. The other is to place the Progressive Dynamics converter into its 13.2 volt mode before starting, then bringing it up to 13.6 and 14.4 as the battery draws less current. Having an ammeter is pretty important to control all of this.