Propane vs Auxiliary Battery both with Solar Panel

cmockbike

New member
I am an avid outdoor adventure seeker/ mtn biker fanatic/ DIY'er. Im finally going to pull the trigger and give myself the living accommodations to fit my lifestyle. Ive sold my house, and will be trading in my car, and am totally ready to start my adventure and begin appreciating all the little things that make life so awesome :) With that Im going to be converting a Sprinter van for living quarters, mostly basic, but with some splurges.
The Sprinter I am accustomed to was all ran off a generator and or an auxiliary battery under the passenger seat. Now most of the conversions Im seeing, all the appliances are ran off of propane. Which is more efficient both energy and cost? I really want to have a solar panel, but unfortunately I lack any knowledge in the department of wiring, voltage, etc..

Basically, I guess I really need to know where to begin. After I make my purchase of course :)
 

showkey

Well-known member
I lack any knowledge in the department of wiring, voltage, etc..

Basically, I guess I really need to know where to begin. After I make my purchase of course :)
One suggestion would be to buy a completed conversion and make minor upgrades to fit your needs.:thumbup:

Any start from scratch construction or major renovations is going to involve a ton of wiring, relays, batteries,switches fuse panels, chargers etc (electrical knowledge). NOT to mention woodworking and cabinet making skills.

Heating and cooling anything (air or pots and pans) microwave with battery power is challenging that's where propane excels.......cook tops, furnace, hot water heater, propane frig and (gas, diesel or propane) generator to run A/C and recharge batteries off the grid if needed.
 

icarus

Well-known member
Arguably, propane is a cheaper alternative.

While solar panels are a reasonable alternative to stretch the run time of house batteries, in fact enough PV to run an off grid RV 100% is not really viable. Propane for cooking and fridge is a good place to start. Very high efficiency electric fridges are an option, but most will draw ~ .5 kwh/day.

All battery based design considerations should be based on the (real) estimated loads. Add up all the loads and their duration to get an idea of how much electrical power you will actually use with various scenarios. Two truths exist in the off grid world. The first is that people always underestimate their loads, and at the same time they over estimate their solar capacity.

A simple rule of thumb, in the off grid world is,, take the name plate rating of the PV, divide that number by 2 to account for all cumulative system loses, then multiply that number by 4 to account for the average hours of good sun one could reasonably expect on an average daily basis through out the year. (Most people think they can get more hours,, but in the real world, between cloudy days, shade events, seasonal changes etc 4 is a pretty good daily average).

So a 200 watt PV set up (which would be about the limit on a sprinter roof might look like this. 200/2=100*4=400 watt/hours/day. In an RV application it actually gets much worse, primarily because the PV is seldom if ever oriented ideally. That 400 wh would barely run a good fridge for the day as a simple example.

Like I said before,, do a good, accurate load calculation before you buy/build anything and consider your options. For example, a 9 gallon propane tank keeps us going with cooking, fridge, water heat for about a month. A small Pv would allow us to keep the house batteries charged to run the water pump and efficient lights. Remember, for example a TV might draw ~75-150 watts depending on if you are running a dvd or sat box. Watching that TV for 4 hours a day would use all the available power from said 400 watt PV.

Icarus
 

cmockbike

New member
Quite frankly, a purchase with a full or partial build out would be too costly. I should have given a bit more info in my original post. Im not concerned with the build out, for I have a secret weapon, my brother :) He's an unbelievably talented craftsmen. He also knows wiring, however, this project will be completely different than anything he's ever done. I just want to understand as much about the right approach as possible. Like where to start and what should/could be added later as finances allows.
My two main splurges will be the Espar heater (i like that it runs of the diesel in the engine, and i've had great experiences with this type) and the fridge. As far as Im aware, the heater doesn't use any additional energy, but if it does, its minor. I haven't decided which kind of fridge to go with. I used an ARB cooler all summer, I was told it runs off the amount of energy as 1 LED light, which is why I thought just using the auxiliary battery would be sufficient, but I do not like the cooler set up. Its not convenient, whatever you were looking was always at the bottom, but it kept everything very cool even in the hottest days.
I am leery about doing too many cuts into the body, which is my concern about the propane. It seems there need to be a lot of ventilation which means. I kinda feel like maybe I should do some trial & error with just a camp stove and wait to add this later if I see it fit.
With all of this said, if Im headed down the wrong track, I want to know.
My reason for the Solar panel was mainly to continue charging the auxiliary battery while Im off on a mtb adventure for the weekend. Would this be more practical then expecting it to run a microwave or refrigerator? Or would the generator take care of that issue?
 

icarus

Well-known member
As I said before,, don't discount any load, no matter how small. The Espar heater will draw some power, and the cumulative draw, if you were to run in for say 23 hours while cold weather camping would be significant. For example,, a 2 amp draw over the course of 24 hours is a 24 amp/hour draw, which is a pretty hefty daily draw on a 100 ah house battery. Add in other loads,, and you can see they add up pretty quickly.

I would be skeptical of any fridge (or cooler for that matter) that only uses as much energy as "1 LED". I don't think that is even theoretically possible, much less true in the real world. Like I said a good quality electric fridge will use as much as ~ 500 watt hours/day.

A very efficient Engle fridge will use between 1-4 amps. Estimating a duty cycle of 1/2 time, a 3 amp load, would be 36 ah/day, or ~ 432 wh.

Icarus
 

Top2004Cub

'08 3500 Extended Mega
There are some obvious "Apples and Oranges" issues going on here... :thinking: In comparing systems for heating, cooking, and other energy consuming activities, I made up a grid of what benefits each system could offer, and at what cost.

Diesel is already on board, requires no additional space for storage, and is not explosive. It can supply heat for cabin comfort, heat for cooking, and heat for domestic hot water. It can also supply pre-heating for the engine. Diesel furnaces are more expnsive, and will require some maintenance... service about once a year I am told.

Propane is likely the least expensive system to install.:hmmm: It is capable of supplying heat for all the systems mentioned above, although I know of no-one pre-heating their engine with their propane furnace. (this should be easy to do) It does require tanks that come with a host of issues and special requirements, and if anything should crack or leak for any reason, you and your family could wake up dead. Alarms are mandatory, as are venting and care to keep all appliances in good working order. It is by all accounts a good value as far as BTUs per dollar spent, and you can power heat sources as well as refrigerators. (not nearly as efficient here though)

Batteries and solar systems are expensive and limited in their abilities. :wtf: They can be used for cooking, running pumps, fans, communication, and entertainment systems. Typically batteries are charged by running the engine, or plugging in to shore power. A solar panel simply extends the time interval between either running the diesel engine, the generator, or plugging into shore power. If battery capacity is great enough, this interval may exceed the duration of the camping trip.:bounce: Large battery/inverters systems offer the additional capability of allowing virtually any 110 volt appliance that can be envisioned including air conditioning and microwave ovens. Batteries and solar panels can both be easily mounted so as to not use up precious "living space". Solar panels are always mounted on the top of the vehicle, and batteries can be buried down in the "innards", particularly if they are the AGM variety.

You have to have batteries with either diesel or propane to power the various systems, timers, thermostats, etc. You don't have a choice in this. The question that remains is how often will you need to charge your house battery, and with what methods. You have an alternator on the van engine that is available, and maybe shore power, but maybe not...:rant:

Generators are powered with propane. diesel, or gasoline. The cheap ones are powered with gasoline, requiring separate fuel storage issues to be resolved. Propane generators work fine if you have already made the decision to install a propane system. Diesel generators use fuel already available in our Sprinters, but they are the largest, heaviest and most expensive of the three types. All are noisy and all require places that can accommodate the heat that comes with their operation. :shhh: Assuming an inverter, a generators only function is to charge the house batteries. Vehicles without an inverter will essentially only use the generator to power the air conditioner.

There are many ways to skin the proverbial cat, but in consideration of the above, I chose to go pretty heavy on the batteries, with four big ones, and to supplement their charging with solar panels. I'll forgo the generator and propane system, and rely on my superior planning to be where it is sunny when I am on vacation. If I am lucky, I should be able to camp without running the van for several days at a time in the sunshine. If it is raining, then I am going to charge the batteries with the van on my way to where the sun IS shinning!:clapping: I'll cook with either an induction cooktop, or microwave when I am inside the van, and hopefully enjoy grilling over a campfire when I have indeed been able to correctly anticipate the weather. Since I anticipate using the van for mostly one or two day jaunts, I doubt I'll need to worry about running the batteries low even in rainy conditions. In any case, with good monitoring equipment, I have lots of options. If my solar system can generate it's rated capacity for four hours a day, and I use twice that per day of camping ... I can stay in one (sunny) place for over five days without starting the engine. (I can use 4200 watts per day at that rate.) Without the sun, I am a two-day weekender.:thumbup:

So, how are you gonna skin YOUR cat? :rolleyes:
 

PeterInSa

Active member
I suggest 2 x 80watt Solar Panels on the roof upgrade to 120 watters if you have the roof space + 120Amp/Hr Deep Cycle battery along with a 20Amp Sola Controller.

For Heating would fit a Diesel Heater which in Australia can be done by a handyman where as a Gas Heater needs to be installed by a licenced plumber. But if you are also installing Gas Hotwater system and a gas stove along with a 3 way frig (Gas/12v/110vac) all be connected up by the plumber at the same time.

Peter
 

icarus

Well-known member
Most Dometic items are widely available in th US,, even at places like Camping world.

Icarus
 

cmockbike

New member
Diesel is already on board, requires no additional space for storage, and is not explosive. It can supply heat for cabin comfort, heat for cooking, and heat for domestic hot water. It can also supply pre-heating for the engine. Diesel furnaces are more expnsive, and will require some maintenance... service about once a year I am told.

Where can I find the diesel units for cooking and hot water?
 

nugget

Member
Looks like a great products but way too expensive. Propane is easy to plumb and price competitive. I wish someone could prove me wrong.
 

david_42

Active member
My reason for the Solar panel was mainly to continue charging the auxiliary battery while Im off on a mtb adventure for the weekend. Would this be more practical then expecting it to run a microwave or refrigerator? Or would the generator take care of that issue?
One of the good compressor fridges, yes. A microwave, not likely. Figure 1100 watts at 110. That's 100+ amps out of a battery. Looking at the calculations above for solar, 400 watt-hrs is ten or so minutes on the microwave per day.

There are some very nice small diesel generators out there. Not cheap, but you'll be able to run them for decades.
 

cmockbike

New member
So what if I hold off on the idea of propane for the moment, but get a refrigerator that runs efficiently off of the auxiliary battery and use a trickle charger?

My hold up with propane is a)storage, b)explosive c)cutting into the body to create proper ventilation..

Thank you all for your awesome responses, you all have truly valuable advice/arguments :thumbup: and info!:bow:

I think Im definitely going with the gasoline generator. Honda makes a super quite geny that runs up to 9hrs on one gallon. Pricey yes, but well worth it in the end.
 
Last edited:

cedarsanctum

re: Member
I do not recommend the Wallas stove, and Scan Marine will not sell it to you to install in an RV (been there, done that). Webasto makes one very similar but without the 'heater conversion lid' (which is too noisy anyway), but it's hard to find and expensive. Stick with a small camp stove.
I have an efficient compressor fridge (made by Waeco, now Dometic) powered from the factory 95ah auxiliary battery and a 130W solar panel. In the summer when there's lots of sun available there is no problem keeping things the right temperature, plenty of power as long as i get 3-4 hours of good sunlight a day on the panel.
The Espar D2 furnace has more than paid for itself as a heating appliance, and i would recommend this as one of the best purchases for camping if you do a lot of cold weather camping.
I chose to not have any propane devices plumbed into the van for simplicity (one fuel source for heat and cooking), safety (gas is explosive), and cost. Adding the price of having a propane system installed would negate any savings from the price of the appliances available. If i had it to do again, the only change i would make is to not get the Wallas diesel stove. Most of our cooking is done outside in the summer, and during the winter i mostly don't need to cook inside.
Just my 2¢
Jef
 

d_bertko

Active member
I have an 02 158" 2500 DIY that I built for year round drycamping. My first conversion and everything I needed to know I learned from helpful folks on the Web.

My van has well insulated walls and ceiling and the goal was to cut the heat load down. The Espar d2 diesel furnace is wonderful. It is fairly efficient electrically. (Many complaints about noisy propane furnaces that run a single battery down overnight. This is better but the electric draw can not be ignored.)

My design goal electrically was to be able to run an efficient Engel dc fridge for a few days and a compact microwave and magnetic induction burner for a couple of meals. My 2000w psw inverter paired with a 420 ah bank essentially gives me the equivalent of a stick-house outlet. So almost any consumer product will run. The bank is large enough to support both the short 110a draws for the ac kitchen appliances as well as the round-the-clock low draw of the dc fridge.

My roof is full with a walk-on boat rack and my New England is shady and cloudier than the dry West. A solar installation was not too practical and much more expensive six years ago. So I bought a quiet Honda eu2000i genset figuring I would have trouble maintaining the batteries otherwise.

Well, I was mostly wrong about the genset. As long as I drive somewhere, even food resupplies, every four days I can run off alternator amp-hrs alone. No shore power needed. No solar needed. Mobility is a key to owning a "B". Larger campers get greater solar benefits since they don't move as much when drycamping.

The secret to our luxurious camping lifestyle is the propane locker. We cook a huge proportion of our meals outdoors on a campstove and bbq. Also use the bbq tank to heat water for our portable shower. Lots of btus needed so this is our in-camp method. I used a standard plumber's propane locker and drilled the floor and sidewall holes to give it the required venting. Making your own is straightforward and lots of examples from the marine world.

Meals on the road essentially offer unlimited kw-hrs from the alternator and no propane is needed. The electric "inside" kitchen is cool, safe, convenient.

No underside tanks because of the freezing temps sometimes. No propane plumbing since we have diesel heat and an electric kitchen when needed. Replaced the Portapotti with pee bottles and a wagbag system. Portable shower is used inside or outside.

I can carry four road bikes on the hitch rack and three canoes on the roof. I park on a city street at home and have the option to daytrip with both a boat and/or a bike stored inside.

I will leave it to the others with less compelling cargo needs to go the fine furniture route.

Dan
 

brassarl

2006 T1N 2500 Long & Tall
Arguably, propane is a cheaper alternative.
A small Pv would allow us to keep the house batteries charged to run the water pump and efficient lights. Remember, for example a TV might draw ~75-150 watts depending on if you are running a dvd or sat box. Watching that TV for 4 hours a day would use all the available power from said 400 watt PV.

Icarus
FWTW yesterday I sent a friend over to Sams Club to buy a 19" LED TV @ 22 watts; they came back with a 21" LED@ 32 watts (3 amps) $190 and it uses an adapter to reduce 110 to 12V. So its a 12V LED TV, Ideal for our applications, no inverters.. just plug it in to 12V. You want to watch DVDs, use your laptop with HDMI cable and your off and running!

Happy New Year!!
Lou
 

icarus

Well-known member
Or avoid the middle man'and watch the DVD on the lap top.

There are several small flat screens that are native 12 vdc.

Icarus
 

windsolar

New member
I lived off grid for 20 years with a solar and wind systems and batteries with inverter. From my experience the main problem with batteries is they only hold so much energy and even if you increase your solar input the batteries end up fully charged by a few hrs of sun and then you go into trickle mode, then at night when you need that power it gets used up real fast. Especially if you start running a lot of appliances. Propane is great as it can meet a lot of your energy needs, but it is a fossil fuel and is expensive. The entire point of having a Sprinter in my humble opinion is to decrease your dependence on fuels. Thus, the only way to do this is to use less. Make the conversion simple and limit your electrical needs. then the propane should meet your needs. solar is good as a supplement for lights and TV, but not good for higher load needs like the fridge. By the way, I now am on the grid and have a 10K solar array that turns my meter backwards. I have three VW TDI's that I run on filtered veg oil. Check my blog out.
www.solargrease.blogspot.com
Windsolar

So what if I hold off on the idea of propane for the moment, but get a refrigerator that runs efficiently off of the auxiliary battery and use a trickle charger?

My hold up with propane is a)storage, b)explosive c)cutting into the body to create proper ventilation..

Thank you all for your awesome responses, you all have truly valuable advice/arguments :thumbup: and info!:bow:

I think Im definitely going with the gasoline generator. Honda makes a super quite geny that runs up to 9hrs on one gallon. Pricey yes, but well worth it in the end.
 

icarus

Well-known member
I have lived off grid for better than 20 yeast as well. Two rules,, amongst many more. All loads grow with time, batteries need to be properly sized for loads, and finally people always underestimate the amount of power they use. (I guess that is three)

Icarus

PS the fourth is that people often kill thier starter set of batteries due to ignorance, and five, RV owners tend to be much worse than true off grinders. I guess I will stop,,,
 

Top Bottom