Power supply & Power inverter for boondocking

RoyB wrote:
It has been my experience to beef-up the trailer first to run all the things you want to run from the batteries. Then add the 2KW generator to that to be able to connect to the shore power cable to allow your on-board smart mode converter/charger to recharge your batteries in as little as three hours time which is the only way to be able to recharge a deep cycle battery setup.

Using the generator is the only "sure" way to re-charge your batteries as it will work in all weather situations.

Once you get successful running all the things you want to have with you then start adding some solar panels just for the purpose of re-charging your large battery bank during the daytime when the sun is out...

This is where I am now in my long term beef-up for camping off the power grid. As you start increasing the solar panels then you can start cutting back on the use of the generator. Eventually you can go several days without running the generator at all and still be able to run all the things you want to run.

But what I have found out you will need to always have the generator around for that last PLAN B effort for keeping the batteries re-charged. You may go weeks without much enough sun light to run the solar panels...

Got to have the PLAN Bs to be successful camping off the power grid...

Just some of my thoughts on how we have progressed along the camping off the power grid experiences...

Also if you are lucky enough to be able to have your RV Trailer parked at your house when not on the road then all of your Battery beef-up planning is like having a large UPS system for your house when bad weather storms knocks out your power for weeks on end. I have used my trailer setup to support the house on four occasions now, One event was for over a week without power here in the county when one of hurricane Irene came through a couple of years ago... this payed us back big time and also helped out in the community here helping folks keep their fridges powered up a couple hours a day. My neighbor RV guy and I put the 2KW Honda generator in a kids wagon and visited all the local elderly folks houses and kept their fridges going. All it cost was a cup of coffee and some conversations hehe...

Roy Ken

This works a treat... Have a Honda Eu1000i that I bought long before the travel trailer, for emergencies. Bought a 21 foot travel trailer and I've been struggling along with charging 2x a day and lights until around midnight on a single Group 24, 75 amp amp hour. It just gets sucked down too fast at night, think the refrigerator ignitor has a draw too, plus radio.

Bought a new Honda Eu2000i so I can at least run a coffee pot or a microwave in the morning, while doing the brunt of the heavy recharge portion for an hour.

Bought 140w worth of solar panel and a charge controller. Good for about an 8 amp charge rate under ideal conditions for 5 or 6 hours a day, where I go. Been told a watt per amp hour is generally what you need for solar panels. We will see, but with a generator, as Roy points out, you always have a back up plan B, when plan A gets FUBARed by a rainy day, cloud cover, or smoke from fires.

profdant139 wrote:
Niner, two ideas -- first, have you considered group 31 batteries, with 110 amp hours each? And 22 watts for the bulbs seems high -- warm white LEDs draw about 5 watts and give plenty of light.

These are the following figures for my 21 foot travel trailer, without a slide out.

I just did a power draw analysis with my Kill-A -Watt meter yesterday.

Parasitic draw in Amps at 122.V off my older EU2000i..


Parasitic .33 Amp

Plug in the 22" lcd TV, turned off .46 Amp

Water pump turned on, while pumping to near max pressure + above items. 1.88 Amps

Parasitic + TV plugged in + refrig 3.22 Amps

6 incandscent bulbs /3 light fixture2.17 Amps


lights plus my LED's all on. 2.26 Amps

5 LED's on in fixtures & TV .56 Amps

Water Heater on electric with parasitic 14.76 Amps. Usually run this on propane.

Charger is the variable, I have not run the battery low to 50% and seen the Amp draw yet on the motor.

If you want to save batteries and current drawn... run LED's instead of incandescents. I am still looking for LED's that will fit in those t-10 bayonet fixtures that will give an equal amount of light as a 22w 12v bulb.

My conclusion... if you can, run your generator in the evening/night, the last 3 hours before going to bed, if you can, or shut it off at 9 or 10 pm, and use a quiet generator. Your generator will be loudest when the charging rate is the highest/heaviest, right after start up.

I find that charging up 2x a day, 2.5 hours in the morning, and 2.5 to 3 hrs hours at night, seems to work best for me while boondocking.

pnichols wrote:
Mark,

Are your solar panels attached to the trailer roof with adhesives ... or with bolts through the roof?

Sorry -- didn't notice your question earlier. Our panels are connected through the roof and were installed in the following steps:

- Drilled holes in the roof
- Filled holes with Dicor
- Inserted anchors in the holes
- Filled the anchor holes with Dicor
- Screwed the panels in
- Covered the screw heads with Dicor

We've never had a problem with leaks. Also, there is lots of space around our panels for walking without having to step on or lean on the panels.

We started with a single portable panel, but it was impractical. With 490 watts on the roof all day every day we get plenty of electricity to live comfortably without hookups...

There's a photo of the panels on our roof on the top of this page so you can see how we walk around them:

Solar Power for RVs and Boats

Niner, two ideas -- first, have you considered group 31 batteries, with 110 amp hours each? And 22 watts for the bulbs seems high -- warm white LEDs draw about 5 watts and give plenty of light.

I am currently running a single Group 24 Deep Cycle battery. I need to run it 2 hours in the morning and 3 hours in the afternoon/evening, or the best is doing a 7 to 10 pm charge to get me through the night with the parasitic losses.

Today, after scouring looking for a good used Honda EU2000i for a couple of months, I gave up... everyone wants top dollar for beat to cr*p, run in the dirt, filthy motor oil and air filters weekend warrior Toy Hauler generators that are not in top shape, for 8 to $900, and looking hotter than a $2 pistol. Since I already built myself a pairing cable and a 30 amp box with circuit breaker, I didn't need to buy the Companion model. Now I own a new one, with a known history, mine.

Yep, I got a brand new one, for $900. Before the 2014 price increase, although Honda is getting more and more competition. Paired, I will be able to run my 13.5k A/C. I figure 4 to 5 gallons of gas to break it in for 20 hours and it's first oil change.

I am thinking of getting another group 24, but I may just wait for this group 24 to go soft and then go the golf cart 6v battery route then. Normally, at night, I run 6 22w bulbs, and try to do so with the generator running and the lights on, until shut down time, so as to effect discharge of the battery the least amount of hours over night.

I am curious what is causing the 1-2 amp hour parasitic drag all night long, when everything is turned off, on the battery?

Nice post. I am curious how you draw 150AH Per night?
That sounds awfully high! I find camping with DW, which requires the furnace, inverter for hair dryer, and at least 20 minutes of pump operation, we usually only use about 50AH / DAY.

NINERBIKES - Sorry I didn't respond sooner....

My battery bank is the standard issue GP24 85AMP Interstate Batteries that came with my off-road trailer. I started out with four in parallel and lost one rather quick due to my older converter/charger boiling out the fluids before I caught it. Bee running only three of the 85AH batteries since then. They are just now needing replaced as their performance is not what it used to be.

I probably getaway with using these batteries by watching everything real close with my BATTERY METER PANEL I made up of DC VOLTMETERS and DC CURRENT meter. I never let my batteries get below the 50% charge state (approx 12.0VDC) and re-charge back up to their 90% charge state as quick as I can.

My converter/charger is the PD9260C 60AMP smart mode charger and draws right at 1000WATTS from my 2KW Generator when being used to re-charge the battery bank. Being smart mode this will re-charge my three 85AH batteries in around three hours. I don't think the 1KW HOnda will be big enough to run my PD9260C. Its 1KW output will only give you around 800WATT of usable power to run things. If your converter/charger is dropped back to lower current output then the 1KW Honda would run it ok but in my case I need to draw close to 60AMPs with my battery Bank when it gets hit with the 14.4VDC smart mode charge. It would charge my batteries but "NOT" within the three hour time frame I am allowed to run my generator each day.

I use my DC Meter PANEL to watch this process to make sure the batteries are drawing current when being charged. After you do it a few times you know what to expect during the re-charge process.

My 2KW Honda Generator does just fine running my on-board PD9260C and I also get to make my fresh ground bean coffee for the day when I start this process at 8AM each morning. Alot of places I only get to run my 2KW generator for two hours in the morning and then I have to wait until around 4:30PM to do this all over again to make sure I get a good 90% charge plus before making that evening heavy current draw until lights out and to keep the parasitic drains happy until 8AM the next morning.

I'm not doing anything out of the ordinary just have it all planned and try to follow my plan for each day when camping off the power grid. Really been very successful doing this for the past few years.

I follow another rule not to mess with my truck items for anything except to operate the truck. This includes using the alternator to charge my trailer batteries. My truck is my only way to get home and its non deep cycle batteries will die rather quick if you get them on the down swing of charge.

The truck alternator is indeed a smart mode charging system but it is controlled by the close installed truck start battery and probably doesn't even know the trailer batteries are in the loop to determine the smart mode charging requirements. As soon as the truck start battery get full the alternator will idle back to its float mode charge of around 13.2VDC. If you look up Progressive Dynamics rules for charging deep cycle batteries you will find 13.6VDC will take around 40 hours to recharge a deep cycle battery to its 90% charge state and 78 hours to reach full charge. That would be along time to idle your truck.. If you had large jumper cables directly connected to the truck start battery then the alternator might see your trailer battery bank and stay at 14.4DC Boost mode and perhaps re-charge your trailer batteries in three hours or so. To reach full charge this takes around 12 hours but you really don't need this as your deep cycle batteries will do a good 12-14 50%-90% deep cycle charges without doing damage to the deep cycle batteries.

I am no battery expert here where there are several "real" experts on here that may be able to explain it better than I can. I just made it thru high school and all of my experience is sleeping in Holiday Inn select hotels I reckon...

I do know if I just throw a quick couple of hours charge on my battery bank and when I look at them it shows it might be in pretty good shape but when I really start using the batteries hard they will drop off very quick and the next thing I know I have gone beyond the 50% charge state. You see alot of folks on here saying they just run their generator a hour or so aday and do just fine. That may work with minimal load but it sure does not work with my daily planned out routine of running off my batteries camping off the power grid.

I suspect the same would hold true if I was using solar panels during the day. I would never have enough solar power (14.4VDC at 60AMPS output) to bring my batteries back up to their 90$ charge state in the average 5-hours of high sunlight with just a couple of 120WATT Solar panels. Every panel I read up on only gives you around 5AMPS per panel of usable DC power. I would need four 120WATT solar panel to give me 14.4VDC@20AMPS of DC charge. Thats only good for one deep cycle battery. Now I am not talking about just getting trickle charge from solar panels I want to get my batteries back up to their 90% charge state before I use them again after they have been run down to their 50% charge state over night. Otherwise I end up with bad batteries in the near future. I suspect this would be a hard feat to do with just a couple of 100WATT or 120WATT solar panels. I'm back to running my 2KW generator again but by now I have run out time I am allowed to run my generator. I'm in a pickle haha...

I hope you can follow my thought thinking situation here... I have heard from others I worry about it too much... just do it... maybe so... Again my usual DC power drain is around 1-2AMPS 24/7 for parasitic keep alive drains and I usually see 20AMPs DC being drawn from my Battery Meter Panel between the 8PM to 11PM times running all of the night toys... Check your battery specs and see how long they will produce 12.0VDC@20AMPs and plan from that. Then whatever you take out you have to put back in...

It takes good planning to do what you want to do with your setup.

Roy Ken

Mark,

Are your solar panels attached to the trailer roof with adhesives ... or with bolts through the roof?

If bolts through the roof, how have you kept these through-holes from leaking year after year? If by applying putty around each bolt entrance point ever so often - how do you physically get to some of the bolts without having to walk gingerly over, or lean down on, the panels?

Also, how do you get access to other stuff near the center areas of the roof without having to walk gingerly over, or lean down on, the panels?

P.S. Above are some of the reasons why we have never added roof solar panels onto our motorhome. I may add portable solar panel capability later so as to not compromise the roof's leak proofness (anymore than it already is), and so we can have sun access whenever the RV is parked in the shade. We use a built-in genny off the main 55 gallon tank for A/C and a little tiny Honda (650 watts) genny that just sips the fuel and makes "no noise for all practical purposes" for topping up the coach battery bank anytime regardless of the sun.

On our trailer, which we use for boondocking 100% of the time 6 months of the year, we have 490 watts of solar (three 120's and a 130) and 440 amp hours of batteries (4 Trojan 105 6-volt batteries). It is enough to live very comfortably in our 36' fifth wheel and run everything, including microwave and vacuum (but not the air conditioning).

We have had solar power on two trailers and a sailboat and have lived exclusively with solar power off the grid in these moveable homes for the past 6 years. We've got a lot of info on our website if that helps anyone here:

Solar power for RVs and boats

RoyB wrote:
A 3000WATT load will drain around 250AMPS @ 12.2VDC from your battery bank. Thats a bunch... I imagine the 3000WATT Inverters will require a 400AMP protection fuse be installed between the Inverter and the battery.. You will need a bunch of batteries to sustain this.

We camp alot off the power grid and our biggest load of course is between 8PM and 11PM watching HDTV etc... We use a 600WATT PSW Inverter. We do just about everything we do at regular electric sites except no air conditioner or no high wattage microwave when camping off the power grid.

We will draw around 20AMPS for these three hours from our 255AH battery setup. This along with the usual 1AMP or so draw for parasitic drains all day long will run down our battery bank to around 12.0VDC (approx 50% state of charger) by 8AM the next morning. This is when we will re-charge it back up to its 90% charge state by connecting the 30AMP shore power cable directly to our 2KW Honda Generator. Using smart-mode charging technology this will take around three hours to do which fits into the times allowed by most boondocking camp grounds to run a generator.

We can do these 50% to 90% charge cycles with our battery bank for 12-14 days before we must re-charge the batteries back up to their 100% charge state otherwise it will start doing damage to our batteries. Using the 2KW Honda generator to re-charge to the 100% charge state will take around 12-13 hours which most boondocking camp grounds will not allow you to run the generator this long of time here on the East side of the US so this is usually when we head for the house.

Of course all of this does not include use of Air Conditioning or high wattage microwave.

Usually lots of shade so don't miss the air conditioner anyway...

Roy Ken

Roy, what exactly are you running for a battery set up? Two group 27's or two Trojan 6V golf cart batteries? How many amps at 120v are you drawinng while charging the batteries for 3 hours? Is a Honda EU2000i mandatory to charge your battery system, or would a Honda Eu1000I get the job done?

How long idling a V6 TDI with a 185amp /hr alternator would it take to bring those batteries up to 100% charge every 12-14 days?