Our old Foretravel is equipped with a Sharp Carrousel combination micro wave and convection oven. That means that all cooking done in that oven is electric. As those that have read our past notes know we installed a small solar system and a big bank of batteries complete with a 3,000 watt inverter before leaving home for our winter trip. RV Solar in Phoenix Arizona supplied the system that included 170 watts of solar panels, a Magnum 3000 charger/inverter/converter and the control panels needed to operate the system. The battery bank came out of our golf cart that was not making the trip with us. Read more
I have seen more than one thread in the forums recently concerning the charging of batteries. One question, “can the vehicles alternator fully charge a battery”? Another concerning the best type of charger/converter for battery charging and concerning the cycling of batteries and the effect on battery life.
LIVING WITH SOLAR AND A BIG BATTERY PACK
We added solar panels and redid the electrical system of the old coach, our 19 year old Foretravel. The up date was prompted by two factors. One, we were about to embark on a six month odyssey and second we wanted the option of operating the micro wave and coffee pot without firing off the generator. The question was, is it worth it?
This was more than just adding a couple of solar panels to the roof and some wiring. A good system will include:
- Solar panels
- A voltage regulator for the solar input
- A converter/inverter/charger
- A control panel for the converter/inverter/charger
- A decent sized battery pack
The system provided us from RV Solar Electric in Phoenix AZ included two solar panels rated at 160 watts, a Magnum 2000 watt converter/inverter/charger, the control panels and the 12 volt wiring. For the battery pack there was six Trojan T 105 batteries sitting in my golf cart that would only be sitting at home while we were on our trip. They ended up in a battery bank that also included an 8-D series heavy duty truck battery raising the battery capacity for the house side of the system from 250 amp hours to 1000 amp hours.
This means that we can draw one amp for 1000 hours or 1000 amps for one hour or any combination in between before the batteries are run down to a point that they will not safely operate the equipment. That is about 9.6 volts. The lower the voltage gets in a system, the higher the amperage draw is to operate a unit. It is the flow of amperage through a circuit that creates heat and increases the chance of an electrical fire.
The heart of the unit is the Magnum inverter/converter/charger. The unit has three distinct functions:
- First, it will take 12 volt direct current and turn it into 120 volt alternating current.
- Second, it will charge your batteries with first a fast or bulk charge rate of up to 100 amps, and then drop off to a float charge that will keep the batteries fully charged.
- And third it will take 120 volts, either from shore power or the generator, and provide 12 volts to maintain the batteries and support all of the 12 volt loads in your coach. A good inverter/converter/charger will have automatic switching that will kick in when running the generator or plugging into shore power.
WATTS, VOLTS, AND AMPS
Volts is the electrical pressure in a system, just like the PSI in a hydraulic system. Volts is the push. Amps is the flow of electricity in the system and is like gallons per minute flow in a hydraulic system. Watts is a unit of measure that is volts times amps. Lets just say that the electric toaster on your kitchen counter is rated at 500 watts of power needed to operate. If you divide the watts, 500, by the voltage, 120, you find that the toaster will draw 4.1 amps. In electricity if we are going to draw 500 watts out of one end then we must put 500 watts into the other end. There is a small operating loss but not enough to bother with for these calculations. So, on the 12 volt side again divide the 500 by 12 volts and it comes out to 41.6 amps going in.
In the inverter mode it will run any 120 volt unit that has a current draw of less than 2,000 watts. That equals about 16 amps.
On top of this the solar system will add to the charge rate when ever the solar gain is high enough to raise the voltage above other charging inputs.
DOES IT WORK THAT WAY?
On this trip we just finished 4 days of dry camping in a row as our Thousand trails membership is the 14/7 plan. That means 14 days in a TT park and 7 days out of the system. We did not economize on the use of electricity using the coffee maker and microwave as needed. We watched TV and ran lights and both furnaces at night as the temperatures are in the 40’s overnight. The solar panels are rated at 160 watts under ideal conditions. This 4 days of dry camping occurred in the Sequim Washington area and the conditions were less than ideal. The sun was low in the southern sky and the days were 30% cloud covered. Instead of getting an output of 13 amps from the solar we were lucky to get 5 amps and for only 7 hours a day. That figured to 140 amp hours of power from the solar for the four days which covered the complete needs of the two furnaces, or about an hour of micro wave time, or any combinations, but you get the point. In case you are wondering what happened to the other three days, well we sat those out in Tall Chiefs Resort in Fall City, WA. waiting for flood waters to recede so that we could get to Sequim, but that is another story.
In this latitude this size solar will act to help lengthen the time that you can dry camp but will not comfortably solely support the coach without really conserving use. The thing that appears to be important at this point is to have enough battery capacity to support your system.
After the four days of boondocking, it took a combination, of first three hours of driving and two and a half hours of battery charging with the coach plugged into shore power to bring the batteries back up to snuff. This would have been the equal of five and one half hours of generator time.
How does that compare to the old system that had no solar and only one 8-D battery to support the coach and a 45 amp converter? Before the new system we would have run the generator two hours in the morning to make breakfast and charge batteries and two to three hours at evening meal time to make diner and watch TV making sure that the batteries were up in case we needed heat during the night. That adds up to four to five hours of generator time a day compared now to one and one quarter hours a day average.
On the road we keep the inverter on full time providing 120 volts in the coach keeping the lap top running with Streets & Trips, charging Lucy’s camera batteries, and running the refrigerator on electricity instead of. We switch over to propane when we stop for the night. The alternator on the engine supplies the current needs and provide us with fully charged batteries when we stop for the night, usually around 4 PM.
Even with the limited sun the system has worked and cut our generator use by at least 60%. And at 3 bucks a gallon for propane, run the numbers, it works. Not counting the convenience of coffee without the noise. While it is true that the system, as configured, will not support the entire load and keep the batteries charged but it is better than what we had.
This has been our experience in the northern part of the country in late fall when the sun is low on the horizon and we are approaching the shortest day of the year. After we leave the Seattle area we are heading south and we will keep the log going to see how the system works when we get more sunlight.
The Inverter Is In, And It Works!
To answer a couple of questions first raised in the comments forms, as soon as this old goat learns how to send pictures with the text I will get photos in the blogs.
As far as how I figured how much current that I wanted from my installation, the answer is simple. I figured that this would be the first phase of the installation and that if I could cut generator use by at least 50% I would be happy. The second requirement was that Lucy could plug the coffee pot in when she got up in the morning without firing up the generator. She has the feeling that when firing the gen set up in the morning that it will disturb my beauty sleep, and god knows I need all the Beauty sleep that I can get. She forgets that I take the hearing aids out when I am in bed and without them I can’t hear the generator, as it is up front on a Foretravel.
Now I could go through all the numbers that I ran, but basically I increased the battery capacity from 225 amps hours to just a tad under 1250 amps hours. The term amp hour is a measure of the capacity of a battery. 225 amp hours means that the battery should be able to deliver 225 amps (units of power) for one hour or one amp for 225 hours before reaching a voltage (pressure) that is considered a dead battery. Usually around 9 or 10 volts. With the available 1250 amp hours available I should be able to run both furnaces about 85 hours. Since the furnaces run about half time when the outside temperature is near freezing, making 170 hours of heat for 85 hours of battery drain.
The microwave draws 65 amps of twelve volt power to run the inverter and make the 120 volt current to operate. Typically the microwave is run 2 minutes to reheat and 10 minutes or so for a frozen meal. So given all the figures that I compiled on the spread sheet I figure that the battery pack alone will run the coach for 4 or 5 days and add the solar gain that could stretch to well over a week.
Under ideal sun conditions the system that I installed will give back 100 amps per day. I figure that will be about 40% of what I need to recharge the batteries over the long haul. The inverter/converter/charger that I installed has a 100 amp charging rate, charging the batteries faster using less generator time and fuel. Now another factor is that if we move several hundred miles in a weeks time the engine alternator will bring the batteries up as the engine alternator is a 125 amp unit. I bought the package from RV Solar Electric in Phoenix Arizona because it more closely matched what I wanted for power than anything else that I found.
The last quest was a two parter, what did I find as an auxiliary circuit breaker panel and where did I mount it. The panel was purchased at Home Depot and is a Square D 6 bay unit 12 circuit model HOM612L100SCP for under $20.00. The auxiliary circuit panel is mounted under the bed beside the main panel with 10 gage romex running up to the inverter and back. The output circuits, 2 legs, are protected by a pair of 30 amp breakers in the main panel and then six thirty amp breaker in the auxiliary panel form all the plugs and stuff. There was one more question about a progressive surge protector being hard wired into the system. To be honest I did not consider a surge protector when putting this rig together, but it is a good idea.
As to where did I put the batteries and the inverter? That is where the rub comes in. We drive an older Foretravel by choice. The older Grand Villa’s were a low profile rig. I have a walking disability and stairs are a problem. When we were looking to get out of the front engine Southwind and into a Diesel Pusher I began counting steps. The Southwind had two steps outside and three inside. That may not seam like much to those with no problems but for me the more steps the fewer times in a day that I can negotiate them. Some of these new rigs have six or more steps to get into the living compartment. The Foretravel is three steps from the ground onto the main floor and does not need outside steps.
The problem with a low profile is the reduction in the height of the storage bays. To install this system we lost one complete storage bay, the one in front of the center entrance door where the six Trojan golf cart batteries and battery tray takes a footprint of 24 inches by 27 inches. The height of the batteries leaves just enough room over the batteries to make the connections and service the batteries. The converter/inverter/charger mounts in the same cabinet and it does allow room for a shelf over it.
Now the system has been up and running for two days as a stand alone. Yesterday I was doing some rewiring on my car trailer lights and had the lights on on the coach. I had the Aux switch on connecting the engine battery into the system. The solar pumped away all day and the batteries registered 13.4 volts at the lowest. Today it is raining and cool meaning that I need to turn the coach heat on to get the freezer to work as we are loading up for an early Saturday take off for the grand Adventure. Even in the rain the solar is producing energy and the battery voltage is in the 13 volt range. It works.
The next installment will be from somewhere on the Lincoln Highway in Pennsylvania.
Brad & Lucy aka The Geezer and the hedgehog, and oh ya Earl the Kitty Kat.
Not even close Bunkie, not even close. There are so many different theories on what a good shock is supposed to do that it makes picking one of old Howard Johnsons 28 flavors of ice cream a simple matter. It would appear that Koni, a European company that introduced European ride and road feel to this country, has the heads up at least in the marketing department. Now before you throw something at me, hear me out.
Koni build a very good product, no doubt about it. Koni build a very expensive product, no doubt about that either. Koni builds a very difficult to install product if you are going to use their features to the fullest, no doubt about that either.
Now, the Koni adjustable shocks is a great device. We used them in sports car racing when I was younger, lighter, and had red hair and a red beard (both now gray). There are to ways to install the Koni adjustable shocks. One read the instructions and guess that you would like a ride quality some where between firm and soft, pre adjust the shock, and install it. The adjustment of the shock cannot be done once the shock is installed. The shock must be fully compressed. This allows a spanner wrench built into the shock to contact and engage an adjustment nut in the bottom of the shock. This will turn the adjustment nut when the top of the shock is turned and the bottom is held from turning. Then re-install the shock and road test to see if that is the ride that you want. That is great, you can dial in the ride that you want.
Koni realizing this has come out with a new shock called the Frequency Selective Dampers. According to Koni, “We have combined the benefits of performance and comfort into one shock absorber. FSD is firm for control over large bumps and corners, but soft for comfort over expansion joints and rough roads.” This sounds good and if they re up to Koni’s reputation they should do just fine.
What appears from reading the forums is that Bilstien is the next shock of choice among the aftermarket brands. I have Bilstiens on Rover II, our older Foretravel, and am quite happy with them. Bilstien again evolved from the European sports road sedan market and again like Koni were very succesfull in the variable valving of shocks to be soft under minor bumps in the road and yet stiff enough for good overall control.
Bilstien says in thier web site, “Motorhomes are a great form of travel and recreation. But are they a joy to drive? Wallowing, top heavy, boat like, all phrases that have been used to describe the ride and handling of an RV. But not with Bilstein. Instead words like precise, confident, controlled and safe are what is said about a Bilstein equipped coach. With Bilstein, you won’t find a generic ‘heavy duty’ shock with ultra stiff valving and terrible ride characteristics, but rather a shock designed for your specific motorhome application providing you with a safe and compliant ride.”
Bilstien claims in it’s site that working with Monaco it has, “The World’s First Active Damping System Developed for the Motorhome Industry. BILSTEIN’S ACD SYSTEM (Active Control Damping) automatically reacts to changing road input and coach motion to deliver optimum ride comfort and safe handling.” The claim is that it is a computer controlled system that adjusts the shocks to road input. This type of suystem is a factory installed option as the cost of retorfit would be prohibitive.
Well as usual I have used up all my space for this week and next week we will look at what other companies are offering for ride and handling control. Till then keep camping.
This trip has been a year in the planning and preparation. Last summer we trekked across the US to attend daughter Becca’s wedding. The trip was a six week adventure that ended all too soon. Just around Christmas we were informed that a new grand daughter would arrive in the Seattle area in mid summer, so another trip cross country was in order. Then the gears in our heads began to churn and we came up with a grand plan.
Back in the dark ages, 1984, when I was younger, I did things that normal people would consider a bit on the loony side. One such adventure was dreamed up by Brock Yates, former racer and auto journalist, called One Lap America. It was the natural progression of Sea To Shinning Sea Dash that duplicated the fabled coast to coast non stop dashes in the thirties by racer Cannon Ball Baker. The run, made famous in a movie cannonball Run staring Burt Reynolds among others, started in New York City and ended in California some 30 plus hours later.
One Lap was a little different. We left, spaced at one minute intervals, from Derian Connecticut determined to drive the perimeter of the country in seven days. We did it, and it was for the auto nut a true blast. Well now in my seventh decade of life, I have decided that seven days is too quick and seven months ought to be about right.
Back then our steed was a modified Mazda Diesel Pick up. My son Steve took the truck and modified the suspension and added a turbo charger to the engine. He tweaked fuel injection system, added a roll bar, trip computers to the dash and a lot more. My co-driver on that trip was Bill Scheller a Vermont based free lance writer who was sending reports to the Christian Science Monitor and I was doing TV for PBS. We had one overnight stop on the trip, at the Portafino in Redondo Beach California.
This trip will be in our 1990 Foretravel Grand Villa, Rover II, pushed by a Detroit Diesel. The co-pilot is DW Lucy and there will be many stops along the way. Tagging on the back will follow our car trailer with Subie the Subaru Outback along for the ride.
So this trip is New Hampshire to Seattle. A visit and thanksgiving with Becca, Tobin, and Elise, the new grand baby. Then down to San Diego and hook a sharp left. Of course stopping In San Francisco, and other points along the way. Then investigate the great southwest and on to New Orleans. More family and Jazz festival are the plans for visiting the Big easy. Across the gulf coast to central Florida and more kids and grand kids to visit. While traveling north up the east coast we are going to try to find some friendly blue fish and stripped bass along the outer banks. And then back to New Hampshire after the roads dry out from spring mud season.
Both Lucy and I will be writing blogs along the way and posting them here. Lucy is a former news gal and managing editor of the Mansfield News in Mansfield Massachusettes. We are both published photographers and will try to learn how to post our photos with the blogs.
But right now I am making lists and checking them twice to be sure that I have done what I need to to make sure that an 18 year old motor home is ready to go. The next blog in this series will be a list of what I have done to get ready. I will be interested in your comments as to what I have missed.
My next regular Monday blog will look at Shocks, not the electrical kind, what they do an how they work.
Brad & Lucy
Well I really stepped in it last week and as Sven pointed out about a minute after I posted that I did not answer the question in the title. That was what is the correct tire pressure? Well, if we hang in a bit I promise that I will answer the question. A hint is that there is no one answer but perhaps we can clear up the formula.
Larry wrote that the “air limit is stamped on the side wall of the tire”. That is basicly true but there is also a weight stamped with the PSI number and usually more to the statement. larry has it half right. The Firestone T559 tires sized 9R22.5 12PR on my old Foretravel says the following: “max load single 4540 LBS at 105 PSI cold,” and then a second sentence, “max load 4200 at 105 PSI cold.” First of all why the difference in the tire pressure between single and dual? According to my sources it is the clearance between the dual wheels to make sure the tire side walls do not touch during deflection.
The statements on the tire side walls says that you can carry 4540 pounds of weight at a specific pressure and the tire will have the correct foot print and side wall deflection for a combination of low heat build up, good ride and handling and good tread wear. The entire statement must be taken in context and does not mean that this is the correct tire pressure under all conditions for this tire.
Jerry wrote, “OK under inflated is not good. So where do I get an accurate tire gauge? Where do I find a air pump that will properly fill my tires?” Well Jerry I use a digital tire gauge that I bought from the Northern Tool catalogue. My compressor is a Campbell Hausfield 110 volt 100 PSI that came off the shelf at Wal-Mart. It is a bit slow but it does do the job.
Roger, a tire designer, wrote, “I am a tire design engineer with 38 years experience. I teach tire failure analysis ( Think CSI for tires) so let me correct a few minor points and answer some of the questions.
The correct inflation is based on the actual load you are running. The inflation information in your owners manual is based on some assumptions on how much weight you are carrying. I have heard of some vehicles being only capable of adding 5oo# over their empty weight before the tire is overloaded so the only way for you to know the real answer is to get your vehicle weighed for each position. Then contact a tire dealer and ask if he has a load inflation chart (or check the manufacturers web site). If he doesn’t find a different tire store. The correct inflation should be something below the max infl on the sidewall of the tire. Only check your inflation when it is cold – not in the sun and not driven on for at least 4 hours.”
Roger says it all. Weight the rig, at least each end and preferably each corner with your travel load, and then compare the weight with the makers tire chart and determine the correct pressure for conditions.
Now stay tuned for next weeks blog when we will hear Gordon say, “I recommend doing a Google search on Nitrogen in tires. The information will make the choice a no brainer”.
Just Some Thoughts
During the past two weeks, DW and I cruised the coast of Maine on a lobster and lighthouse tour. The RV traffic was light and there was not one “No Vacancy” sign to be seen. We had our choice of campgrounds without reservations. We took all blue roads and kept the speedometer below 55. I was playing as usual, only this time being very intune with fuel economy while being a safe driver. Below are a few thoughts that ran through my addled mind while on the road. Oh, doing a lot of stop and go driving, you know those antique shops keep hollering STOP, we managed 10.79 miles per gallon for a thousand mile run. That is not towing and Rover is a 1990 38′ Foretravel with a Detroit 8.2 and 4 speed Allison.
Meet Tommy Knocker
Growing up around Boston sixty years ago, every kid knew what a Tommy Knocker was. Do you? It was what you used to clobber Tommy over the head. Today my Tommy Knocker is a small ball peen hammer that sits under my recliner right by the door of Rover. It is not used to knock Tommy over the bean with but rather to play the 6 kettle drums on the coach when I stop after a run.
Yep, the tires on your rig are a musical instrument and can be tuned by changing inflation pressure. If you walk around your rig and knock the tires in about the center of the tread, it will let out with a musical note. Now that note will not tell you the inflation pressure of that tire, but if all six tires (if they all have the same pressure) will have the same note. A lower pressure will have a lower note and higher pressure will have a higher tone.
The other thing that shares the same place with the Tommy Knocker is a digital infra red thermometer. As I make the circle check of the rig right after pulling in off the road I check the temperature of each tire tread and the center hub of each wheel. Tire temperatures that are uneven can indicate uneven tire pressure. High temperature of the thread indicates possible low pressure. High and uneven temperatures of the hubs can indicate uneven or dragging brakes or problems with a wheel bearing.
BMW several years ago stated that getting up to speed quickly actually saved fuel. What I did was use the turbocharger boost gauge as a driving signal. During acceleration I kept the boost in the lower third of the turbo range. That gave decent acceleration while letting the transmission upshift at lower speed.
When climbing hills, and there are plenty of 9% grades in Maine and New Hampshire, I worked the shifter, the boost gauge and the tachometer when climbing. That is keeping the RPM’s up to 3/4 of red line with the boost gauge somewhere in half gauge range. The RPM’s keep the coolant circulating and the transmission cool preventing overheating. And remember to descend a hill in the same gear that you used to climb the other side using as much engine braking as you can. It also saves a lot of brake.
There are other tricks to fuel economy as well. Try to never accelerate going up hills, accelerate on the down hill side using gravity to help get speed up. Drive ahead, watching cars stop lights 5 or 10 cars ahead allowing you to let off the go pedal well before hitting the brakes. Coast up to stop lights, remembering that using the brakes you are scrubbing off speed that you paid for to get.
A little practice you can get real smooth, not be a slug obstructing traffic, and save some real bucks at the fuel pump. Well with that said it will be back under the coach next week.
More Under the Coach Stuff….
By Brad Sears
Ok, when we last left our hero he was under Rover (our old Foretravel DP) and just exclaimed OUCH! Yes, you are right, I would not have exclaimed OUCH had I had on my mechanics gloves. When we started this journey into the ragged edge of the coach (the interior is finished but there are many sharp edges underneath, even the best built units.) For that reason we need to add mechanics gloves to the safety glasses that we mentioned in the first of this series.
I need to add a bit here to the Polygraphite bushings that I removed from the sway bar links on Rover. The bushings that I removed from the sway bar set up on the front of Rover were not totally worn out. But being a hard material, they had enough old age and wear that they would not absorb the sound of them working when the rig hit a bump in the road. Do not get the notion that I am against the Polygraphite or any of the newer material bushings that some consider the second coming of the bushing prince. But each type of bushing has it’s place.
Lug Nuts latest blog on Aluminum Wheels was, as his usual product is, great. I have aluminum wheels on Rover, our 1990 Foretravel DP, and they are great. But there is one great advantage and that is that they are lighter as Lug Nut said. And as he said that reduces unsprung weight.
With Lug Nuts permission I would like to expand a bit on the mystery of unsprung weight other than the general weight reduction of the rig. Unsprung weight is the weight of the components between the springs and the ground. That includes the tire, wheel, bearings and hub, brake rotor or brake drum, caliper and pads, brake shoes and springs, wheel trim rings, lug nuts, and suspension members between the springs (or air bags), and the ground.