Instead of a bigger Battery

[mike837go]

When we camp, the battery has never been enough. Even in my more 12V efficient old trailer.

So, considering gasoline has about 300 times the energy density of lead-acid batteries (45,700,000 vs. 146,000 Joules per kilogram), I decided to go a different route to have enough 12VDC power when we boondock.

I built a 12VDC genset from a new ($100 Harbor Freight engine) and other bits and pieces:



The instructions for building one of theses is all over teh intarwebs. http://www.metalwebnews.com/howto/ge...-generator.pdf

Connecting it to the RV is more fun:


I used 175A genderless DC connectors (similar to a previous project).

The little bugger stows easily:


So one 2 gallon can of gas (about 6.3 kilos) has the equivalent energy of about 1,900 kilos (literally, a couple of tons) of lead-acid batteries.

Even considering the HUGE INEFFICIENCIES of converting gasoline to electricity, I'm still ahead of the game in the amount of weight carried vs. the amount of electricity I'll have at my disposal when camping.

Couple this little guy with the RV's battery and a 2,000Watt inverter (from that other project) and I can run my coffee grinder as much as I want.

[Murff]

Interesting, but is it noisy?

Murff

[Camper_bob]

Originally Posted by Murff

Interesting, but is it noisy?

Murff

+1

[mike837go]

Originally Posted by Murff

Interesting, but is it noisy?
Murff

Depends on your definition of "noisy".

Running the OHV 79CC engine with a modern muffler at under 2,000 RPM is a heckofalot less noise than the 5HP L-Head at 3,600 RPM.

And because it directly charges the battery, total running time of the engine is much less than using a 120VAC genset and charging via the converter.

Is it quieter than a good Honda inverter? I doubt it.

[Mustang65]

I hope you art going to store it in the TT's compartment with gas in it...
Don

[mike837go]

Originally Posted by Mustang65

I hope you art going to store it in the TT's compartment with gas in it...
Don

Long-term storage? No. It lives with the other gensets in the barn.

Transport to and from our boondock spot 4-5 hours? Yup. Strapped down.

The gas can goes in the pickup's open bed.

[Rhumphers9a]

Originally Posted by mike837go

Long-term storage? No. It lives with the other gensets in the barn.

Transport to and from our boondock spot 4-5 hours? Yup. Strapped down.

The gas can goes in the pickup's open bed.

mike837go-did you ever think of to use a stationary bicycle with a belt to the little generator, you could kill two birds with one stone!!! get yer battery charged up and daily workout at the same time???

[Bassdogs]

Harbor Freight has a 800W gen for less than $100 just about every month. Got mine for $89. Not the best but works fine for running the pole saw and other 110v tools around the property and used as a back up for my Honda 2000 when it needed service. Your thing seems like a lot of work [tinkering] so just asking, why didn't you buy one built for this purpose since you apparently have access to a HF store?

[Camper_bob]

Originally Posted by Bassdogs

Harbor Freight has a 800W gen for less than $100 just about every month. Got mine for $89. Not the best but works fine for running the pole saw and other 110v tools around the property and used as a back up for my Honda 2000 when it needed service. Your thing seems like a lot of work [tinkering] so just asking, why didn't you buy one built for this purpose since you apparently have access to a HF store?

I've been looking at those for some time. Wondering how well they would do to charge the deep cycle and handle the parasitic draws? We don't boon dock, but for $100 it would be nice to be able to charge up the battery when we need to for the few ocassions we might be out for a night or two without hookups...

[Old skipper]

Great project and is a good low cost answer in support of creature comforts.

[mike837go]

Originally Posted by Rhumphers9a

mike837go-did you ever think of to use a stationary bicycle with a belt to the little generator, you could kill two birds with one stone!!! get yer battery charged up and daily workout at the same time???

I've thought of it many times. But she just won't pedal it for more than 20 minutes at a time.

[djtho1]

That's why you have kids. They could take turns. And, as a side benefit, they would be happy to go to bed and sleep well throught the night!

[mike837go]

Originally Posted by Camper_bob

I've been looking at those for some time. Wondering how well they would do to charge the deep cycle and handle the parasitic draws? We don't boon dock, but for $100 it would be nice to be able to charge up the battery when we need to for the few ocassions we might be out for a night or two without hookups...

A night or two will not run down your battery. When you're into 3-4 with today's parasitic loads, is when you have to start to worry.

Besides, the tow vehicle will leave your battery fully topped up when you unhitch.

My old trailer would go 4 nights without recharging: 20 gallons of water pumped + lights. No radio, no CO detector, all gas appliances were mechanical... Some things I miss.

[mike837go]

Originally Posted by djtho1

That's why you have kids. They could take turns. And, as a side benefit, they would be happy to go to bed and sleep well throught the night!

Sorry, the 'kids' (mine are 25 and 23, hers are 41 and 36) DO NOT come camping with us.

There is exactly 1 usable bed.

Lets see...turn the kitchen into a dormitory for the galley slaves or carry a small cobbled-together genset? Feed a bunch of people who would much rather be somewhere else or carry 2 gallons of gas?

Very difficult decision.

[djtho1]

Lol

[Edd505]

Originally Posted by mike837go

Sorry, the 'kids' (mine are 25 and 23, hers are 41 and 36) DO NOT come camping with us.

There is exactly 1 usable bed.

Lets see...turn the kitchen into a dormitory for the galley slaves or carry a small cobbled-together genset? Feed a bunch of people who would much rather be somewhere else or carry 2 gallons of gas?

Very difficult decision.

I could send ya a 13YOA grandson I'm raising, ADHD & full of energy!

[mike837go]

Originally Posted by Edd505

I could send ya a 13YOA grandson I'm raising, ADHD & full of energy!

What part of "person who would much rather be somewhere else" is so difficult to understand?

Is there anyplace a 13YO actually wants to be? Other than "NOT HERE!", regardless of where "Here" is?

Good luck with your grandson. I'm hoping to start at the ground floor when my kids decide that reproduction is a good idea.

[Seann45]

Originally Posted by mike837go

\
Lets see...turn the kitchen into a dormitory for the galley slaves or carry a small cobbled-together genset? Feed a bunch of people who would much rather be somewhere else or carry 2 gallons of gas?

Very difficult decision.

Galley slaves only get bread and water..

[mike837go]

Originally Posted by Seann45

Galley slaves only get bread and water..

But they still need a place to sleep where the bears won't eat 'em. (The screaming may wake me up. Then I'll have to find new ones.)

So the dinette has to be converted to a bed and then back each day.

I'd rather just leave the genset outside. The bears tend to leave lumps of metal alone.

[RoyBraddy]

We camp alot off the power grid with our OFF-ROAD POPUP trailer.

Our game plan was to install as many items we could that draw less energy such as LED lights etv.. We also purchased a SMART MODE CONVERTER/CHARGER unit that always worded not like what happens with our original WFCO WF8900 series converter.

Then we beefed up the batteries to run all the things we want want to run off the batteries using an Inverter and direct connected to the batteries.

Our battery setup is three 85AH 12VDC Interstate GP24 batteries (255AHs) works great for us and gets to 8AM the next morning at their 50% charge state (approximately 12.0VDC) charge state.

The idea for us is to have all the things we want to use when camping off the power grid in a one day/night run off the batteries. Then at 8AM the next morning when allowed to run our generator we will connect the trailer shore power cable directly to the generator 120VAC panel using an RV30A-15A LONG adapter (WALMART). This will re-charge our 50% charge state battery bank back up to its 90% charge state in a three hour generator run time.

Doing this during breakfast also allows us to brew up our fresh ground and brew BEAN coffee for the day and store up in a thermos...

This works best for us here on the East Side of the US where almost everywhere we camp at including the Natl Forest trails have generator run time restrictions in place... Being OLD SCHOOL We like to follow the written rules...

My Generator lives in the TAIL GATE corner of my truck bed so it is always very noticeable when I am running it. Those of you that have them hidden in generator compartments can get away with running them anytime you want to in most cases.


We have found there is a double standard for those that have the high dollar RV setups - Money talks I guess. We hear the super big RV's running all night long at alot of places we are at knowing they have generator run restrictions in place..

The generator is a must have item for us and adding solar panels would be a great addition to use during the high sun day to help get the batteries charged back up and run the generator less. In my case I have around 52-53 AMPS DC CURRENT demand when my 50% charge state batteries first see 14.4VDC charge DC VOLTAGE. This would take alot solar panels to handle this since a typical 120WATT SOLAR PANEL only produces around 5-6AMPS DC current when in high SUN.

We would run the generator first for one hour to get past the high DC current demand then let the solar panels (typical 400WATT installation) continue the battery charge until we would lose high sun. It works out best for us to the batteries recharged to their 90% charge state as soon as possible. Knowing the solar panels might get them before we lose the high sun but that may be a calculated risk.

In our case we learned along time back not to ever start a day/night run off the batteries unless the battery bank is at a 90% Charge state. Otherwise it gets dark on us around 10PM at night...

We also have found out we can only do 12-14 deep charge cycles to the 90% charge before having to do a full 100% charge state which in our case would take a 12 hour generator run time. This would not be allowed at any of the public places we camp at here on the East side of the US. There are very few DISPERSED CAMPING sites here on the East side... I have never been to a public place where the generator use was allowed after 8PM...

This has been our routine for several years now camping off the power grid with our OFF-ROAD POPUP trailer since purchased in the late 2008 time frame. Camping off the power grid is second nature to us now...

Roy Ken