generator just to charge batteries

40a 14.4v =576w (output) / 75% efficient = 768w (input) / 80% power factor = 960va apparent power required.

Xantrex power factor white paper

ktmrfs wrote:
if you have a quality converter that will output 40+ amps, you'll likely find that a 1000-1500W inverter will overload when the batteries are deeply discharged. Converters draw lots more current than one would first guess. As an example, a PD 65A converter draws close to 13A @120V. My advice buy a honda or yamaha 2000W. cost isn't much more than the 1000W, noise level is virtually the same, and you won't risk overloading the generator.
If your converter is in the 45A range then a 1500W would probably work.

40A at 12 V is only 480W. Try again.

LeBout wrote:

ReneeG wrote:
A Honda? quiet - when cold weather boondocking, we run it in the morning when we are running our heater to warm up.

Why do you need to start a generator to run your heater?

We don't, but after a night of cold camping, if we set our thermostat to 45, heater will kick on in the night (but not as frequent). When we get up we will either turn on the Buddy Heater or turn up the thermostat to 65 and at that temp it runs constantly, hence why we will then start up the generator. Just left out the in between the lines.

ReneeG wrote:
A Honda? quiet - when cold weather boondocking, we run it in the morning when we are running our heater to warm up.

Why do you need to start a generator to run your heater?

The Honda's are pricey without a doubt, but you absolutely cannot go wrong with the 1000 or 2000 series. Super quiet, sip fuel, and as reliable as you can get. Period. Plus if you need more power later on, you can buy the companion version and link them together.

I have a Champion 1000w Inverter that runs as quiet as my Dad's Honda. I don't think they make the 1000 any longer, which is a shame.

Admittedly, its utility is limited. My Dad can run his large power saws and other things off his 2000, but I can't run much more than a drill off my 1000.

HOWEVER!!! Mine is smaller and lighter. And Champion is considerably cheaper than Honda. I wouldn't disagree with the "get what you pay for" mantra, but this is a component of a hobby...not something that my life depends on.

My 1000 is VERY quiet, will run all the mission critical systems, and will run for 10+ hours on a gallon of fuel. Obviously, I can't run the microwave or A/C, but will happily run whatever I can throw at it as far as lights and televisions. As well as running the battery charger. I run the fridge off of propane whilst on the generator.

Good luck with your decision!

K

We have had a Honda 2000w for 3 yrs. We have 2 24g 12v batteries in our new 5'er. We have never had a battery problem yet. Never had a problem with our last TT and 2 6v GC batteries either. We run the gen in the morning for 1-2 hrs, then in the evening for 2 hrs. Once in awhile we skip a cycle but it hasn't made any difference. To be honest, I'm getting tired of dragging the Honda out all the time. We tend to camp in wooded settings and I always try and stick the gen behind a tree or somewhere to cut sound. I carry a 25' cord that I used to use for my 220v welder. It is nice for the wife to be able to use a hair dryer after showering at nite or run the 120v ceiling fan in the kitchen. The key is to not let the batteries drain too much. Less battery drain = less gen run time. But lately I've been looking at solar panels. It's not always sunny here in Oregon but between the solar, the gen and 2-12v batteries I would never have any power shortage. Also thinking of another 12v battery which would allow me to run the gen only when needed. Right now the gen is acting as a solar panel sorta. I could never be w/o a gen, but solar certainly adds another convenience to camping. If I was starting out I would do as I did and go gen 1st, solar 2nd. Gens are just too reliable.

I don't know of an easy way to just use the generator to charge up a battery. You certainly can't use their front panel 12VDC 6-8AMP battery charge cable to recharge batteries in a short time frame.

Consider this progressive dynamics brochure on long it takes to charge a deep cycle battery.
"Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts.

14.4-VOLTS (Boost Mode) – Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours.

13.6-VOLTS (Normal Mode) – Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge.

13.2-VOLTS (Storage Mode) – Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge."

They don't even list using 12.0VDC at 6-8 AMP capacity. This will literally take days of continuous running of your generator to re-charge your battery. This is battery science at play here - not many shortcuts for you to use. If your Marine buddy Joe Schmuckatelli says I just run my generator for a couple of hours a day feeding 12VDC at 6-8 AMPs charge and it works just fine for me. Be sure to carry him a nice cup of hot coffee at 10PM to carry him over for the night.

The best way to do it is to use a SMART MODE Technology like the Black and Decker VEC1093DBD 40AMP portable battery charger plugged into the generator 120VAC receptacle and this will will re-charge your deep cycle backup to its 90% charge state in as little as three hours of generator run time.

We use the 2KW Honda Generator here and connect the trailer 30AMP Shore Power Cable directly to the generator 120VAC receptacle and this allows the trailer ON-BOARD smart mode Converter/Charger to recharge the trailer batteries in as little as three hours. Being connected to the trailer also allows you to do a couple of other things like make coffee etc... Our game plan is to run all of the 120VAC and 12VDC things we want to run when camping off the power grid and have a large enough battery bank to support the inverter and for the 120VAc items and 12VDC item directly from the battery for the one day/one night camping run. Then at 8AM the next morning when allowed to run our generator we can re-charge the battery bank back up to the 90% charge state so we can do all of this all over again for the next one day/night camping run off the batteries.

This allows us to live in both worlds of camping at electric sites and camping off the power grid with our off-road trailer.

Not many ways available to you to be successful about it... Not nice to have the lights go out at 10PM at night because you didnt plan things out so well...

Adding solar power to this layout is ICING ON THE CAKE. This allows you to recharge your batteries during the day time when the sun is out and they don't allow you to run your generator.

Just my thoughts
Roy Ken

If solar will not work I recommend a honda/yamaha 1000 and a Black and Decker 40 amp portable battery charger. Yes it costs more and I think a few years down the road you will agree it is money well spent.

You might be able to skip the portable depending on your converter. Most converters are either too slow single stage or too much power that will overload the small 1000va generator.

Brett50 wrote:
Not that I'm a cheapskate.. but I have a hard time believing that everyone has 500-1000 dollars to blow on a generator just to charge batteries! Doesn't anyone use the non inverter gen.? Maybe build a cover for them to quiet them down?

Many have tried, none have succeeded. A good muffler isn't the answer, much of the noise is internal to the engine. And providing cooling while maintaining the sound baffling is the trick.
I'd try solar but a lot of our favorite sites are shaded. And I'm not about to let some free-standing solar panels grow legs while we're out for the day.