Battery Charging with Generator

[wlanford]

We would like to be able to boondock for extended periods with our 2012 Flying Could 25FB. I think it has the Parallax 7300 converter. If we run the batteries down to 50-60% at night, how long would it take our Honda EU2000 generator to fully (or mostly) recharge the batteries. I would be plugging the shore line directly into the generator. Even though my trailer is new, would I be better off to replace the converter with one of the 3-stage charger models? And what would be the approximate dealer-installed cost of this conversion?

[idroba]

I do not know how the Parallax converter works, as I have a 3 stage PD in all my units now. However, charging any battery to 100% takes 24 to 48 hours (that is the last stage of charging takes a very long time) I can usually get an 85 to 90% charge in a couple of hours with the double Golf Cart batteries I use, if not discharged too badly. A higher amp converter/charger will not significantly change the charge rate in most cases. Batteries only will take a charge at a limited rate which tapers off as they charge, and with the batteries used in most AS's a 45 amp charger will probably work just fine. Anything over 60 amps is overkill and will not shorten the time to charge to any significant degree.

There is probably no exact answer to your question, so much depends on the age and condition of the batteries, the true state of charge you start with, battery temperature, and factors like that. If you have an ammeter on your charge line to the batteries, and you see it drop to under 5 amps, you probably are close to full charge (85 to 90%). Just how long that will take with your system is best determined by doing it and watching it yourself. Our guesses will not be as good as your own experience.

BTW for boondocking a small solar system is always nice to do the last slow finishing charge during the day, after you have done the bulk charge with the Honda and converter/charger.

Your milage may vary....

[Phoenix]

Since you are basically replenishing the electricity that you consumed overnight (or since you last charged the batteries), charge time is mostly dependent on how much you used (since the converter is the constant in this equation). If you used a lot (e.g., using the furnace in winter), it will take longer to charge the batteries the next day. If you used comparatively less (e.g., running the FantasticFan overnight, it won't take as long.

I agree with the above post. You will just have to experiment a little until you figure out how long it takes with your Airstream and your unique electric load.

As a rough example, in the summer, we find that running the generator for about an hour during breakfast, and again for an hour or two during and after dinner replenishes the electricity we used the previous night. The generator isn't run specifically to recharge the batteries. It powers the microwave and television, and the batteries get recharged at the same time.

If we don't use the television or microwave, we can go 2-3 days before recharging the batteries; and a couple of hours of generator time is usually sufficient.

[ROBERT CROSS]

Originally Posted by wlanford

We would like to be able to boondock for extended periods with our 2012 Flying Could 25FB. I think it has the Parallax 7300 converter. If we run the batteries down to 50-60% at night, how long would it take our Honda EU2000 generator to fully (or mostly) recharge the batteries. I would be plugging the shore line directly into the generator. Even though my trailer is new, would I be better off to replace the converter with one of the 3-stage charger models? And what would be the approximate dealer-installed cost of this conversion?

The above posts summarize pretty well our experience.
Our generator use while boondocking is usually about an hour or so every morning.

The Lifeline battery and IOTA 55a DLS IQ4 upgrade definitely helps.

From the bestconverter website...
Note: "Parallax 7300 series are single-stage output converters providing a single voltage output of 13.8 VDC to the DC system for load and battery charging."

This was the primary reason for our converter up-grade. A 3 stage converter is a worthwhile investment.
It is not a difficult DIY project.

Bob

[JBinKC]

We boondocked about 21 days last year, two or three days at a time. I found that with all original equipment, my EU2000 generator had the batteries back up to full voltage before breakfast was over. Most of my boondocking was above 6,000 feet and at temperatures from 40 to 60 degrees. We gained a lot of confidence in ourselves and our Airstream with its original equipment. So I recommend using your new camper as is for this year's camping season. I'll be you'll be delighted with how well set up you are right now.

[mefly2]

Originally Posted by Phoenix

Since you are basically replenishing the electricity that you consumed overnight (or since you last charged the batteries), charge time is mostly dependent on how much you used ...

As a rough example, in the summer, we find that running the generator for about an hour during breakfast, and again for an hour or two during and after dinner replenishes the electricity we used the previous night. The generator isn't run specifically to recharge the batteries. It powers the microwave and television, and the batteries get recharged at the same time.

If we don't use the television or microwave, we can go 2-3 days before recharging the batteries; and a couple of hours of generator time is usually sufficient.

That's our process, too ...

[wlanford]

Is there any advantage to running two Honda EU2000's in parallel for charging the airstream batteries? If my understanding of DC electricity is correct, a 45 amp converter at 12 volts equals 540 watts, which could easily be supplied by one EU2000. Is this correct? Will the converter charge at full capacity from the generator?

[TG Twinkie]

No advantage to running 2 gens if all you are doing is powering the converter and misc DC stuff. The second generator would be need if you were running the AC for example.

[Ahab]

We just came back from Gunnison, Co. boondocking for a week above 10,000'.
Night time temps ran to a low of 28° so we ran the furnace every night and the 2000i for 3 hours every morning which worked real well.