Converting to LiFePO4 batteries and Sailor Man's LiFePO4 Build

[sailor man]

Good news. I was able to reach @sailor man - he has been dealing with medical issues but is doing well now.

I have to apologize about being silent for such a long time. I have been dealing with some medical issues and I have not been able to visit my Morohome since early August.
These issues are not life threatening but they have imposed significant restrictions on my ability to to move the renovation of the coach forward.
I am very grateful that Kendra stopped by to check out how I am doing.
I am having trouble with my knees that is making it very difficult to climb stairs in a normal way. I have also been limited in walking long distances due to significant pain in my glutes.
It has taken some time to diagnose what has been causing these problems and at 83 I began to worry that my sons would be coming for my keys. I have already had to take my mother’s keys from here when she was 70 and my father’s when he was about 77.
I am pledged to use my motorhome for many years in the future and am in very god physical condition. I have been tested for fitness on a treadmill and scored a METS of 10.1 with a pulse of 153 which is 135% of maximum heart rate. That means that I am as fit as a 42 year old man.
However, it has not been an easy task and I am now much closer to were I have to be. I am currently working three days a week, Monday, Wednesday and Friday. In the morning I spend nearly 3 hours working out and in the afternoon, one hour in physical therapy. This regime is very tiring, but I am almost there.
So I will be picking up my pen, writing and I am brimming with more stuff.

So get ready. Here I come!

 

[sailor man]

I would like to talk about what I am trying to accomplish by stripping as much as possible to reduce the air drag on my GMC Eleganza II coach.
Just how slippery was the initial GMC motorhome? According to GMC, the wind tunnel test was performed by an independent wind tunnel, not their own. What do these actually use in the wind tunnel and how was it configured?
The reported Air Drag of the test was 0.31. How does that stack up against the competition?
Well as one means of comparison, my front wheel drive 1989 Ford Taurus SHO had a measured air drag of 0.32 and that was pretty good.
If this is accurate, How did they reduce the air drag to that of a pretty decent 4 door sedan?
They made a test model and lucky they made about 8 additional copies of the model for some of the engineers that worked on the GMC motorhome as a retirement gift.
I was fortunate to find a photograph of one given to John G. Locklin and here is a photograph of it!

So how close am it getting to the test model?

My roof is almost as clean as this model with the following exceptions:

Pros: Cons
Front & rear bumper covers ZipDee awning on both sides
Bogie cover between read tires Sun shade over windshield
Air dam under front bumper Exterior side mirrors
(15) SunPower semi-flexible solar panels & wire
(pretty flat to the roof with no supporting frame)
Low resistance refrigerator streamline vent
Hopefully out of air stream
HVAC Mini-split heat pump
& Continental tire over rear over rear bumper

Hopefully, this is enough to get my coach very close to the listed 0.31 air drag.
Just how significant is the air drag ratio to how many miles per gal efficiency.


I have attached a chart called “GMC Aerodynamic Drag” that I found in the GMCWS technical seminar of 10/10/2006. This data was published by General Motors for a standard 26 feet Motorhome.

Speed Torque HP
40 40 15
55 100 50
70 180 100
80 290 145

When there are storage boxes, skylights, vents, air conditioners, antennas, railings, ladders, rigid solar panels/frames and all kinds of roof mounted items cause a very severe negative impact on the miles per gallon efficiency.
The charts states, “Power to overcome drag grows by the cube of the speed
2 times the speed = 8 x Power
The best payback is to get a much stuff off the roof as possible!

 

[gerryg]

Sailorman, there was a discussion here some time ago about drag figures. Link below. Basically the drag coefficient must be multiplied by the effective frontal area to get the actual drag. The GMC will have more drag than the Taurus by some margin.

Removing stuff from the roof will reduce the drag co-efficient and the area so it’s definitely going to help.

The electric GMC fully imagined -

I have participated in lots of meandering conversations on this so I thought i would put all my silly thoughts in one place. I think a 300-400 mi range electric GMC is totally doable. Some of these numbers are just guesses so feel free to challenge them. A Tesla S weighs 4200 lb with a 1200...

www.gmcmotorhome.org

 

[Matt Colie]

Sailorman,
Specifically to cause this thread to veer off course for just a moment. I thought I had a good knee and a bad knee. I got the bad knee replaced. That was when the calibration shifted and it was clear that I had had a bad knee and a terrible knee. Skip forward about a year and now I really want that bed knee replaced. This is turning out to be an issue as other things were discovered on the way to setting up the R&R one knee. Suffice it to say that I have been hobbling around on a load bearing cane for a while now, but it just changed sides. The best part of this story is that when I was going to get the first knee replaced, I took the advice of a man in one of my social groups and bought a used rollator. This is a 4 wheeled walker with a seat and hand brakes. I can open my gait up to near normal and if I snag a toe on something, instead of a spectacular crash, I lock up the wheels and have a solid and stable pair of handles to steady me. I will be glad to loose it when I have two good knees, but until then, it goes where I walk.
Matt_C

 

[Seankidd]

Welcome back Sailorman.

 

[GlenC]

I feel your pain, so to speak, mine is low back problems from an accident and haven't been doing the work I want on my GMC.

 

[tmsnyder]

Welcome back Sailorman, hopefully you continue to heal up.

I can't remember where I heard or read it, but I believe the wind tunnel was at Calspan (Cornell Aeronautical Lab) in Buffalo NY

 

[sailor man]

Sailorman,
Specifically to cause this thread to veer off course for just a moment. I thought I had a good knee and a bad knee. I got the bad knee replaced. That was when the calibration shifted and it was clear that I had had a bad knee and a terrible knee. Skip forward about a year and now I really want that bed knee replaced. This is turning out to be an issue as other things were discovered on the way to setting up the R&R one knee. Suffice it to say that I have been hobbling around on a load bearing cane for a while now, but it just changed sides. The best part of this story is that when I was going to get the first knee replaced, I took the advice of a man in one of my social groups and bought a used rollator. This is a 4 wheeled walker with a seat and hand brakes. I can open my gait up to near normal and if I snag a toe on something, instead of a spectacular crash, I lock up the wheels and have a solid and stable pair of handles to steady me. I will be glad to loose it when I have two good knees, but until then, it goes where I walk.
Matt_C

I am fortunate that there appears to be no issue with my knee joints, cartilage or tendons. However, I did not get sufficient post operative instructions after the procedure. I was worried about causing permanent damage so I was mostly not moving much that led to muscle atrophy. I now know that but it took a considerable time to get information from my othropedic surgeon. He said physical therapy to strengthen the knee muscles.
So yesterday, with normal activity, 3 hours at cardio rehab and 1 hour at PT, my cardio burn for move was 2,006 cal.
I exercised 256 minutes, stood 14 hrs, climbed 7 flights and took 21,051 steps for a distance of 8.82 miles. I was even able to to do the stairs in the normal fashion.
I have found that it is necessary to work through the pain to regain the strength, flexibility and endurance.
It may be that it is just how my body works but I am still considerably worse that the 10.1 METS treadmill I scored 18 months ago but I am determined to get there.
Never surrender!

I feel your pain, so to speak, mine is low back problems from an accident and haven't been doing the work I want on my GMC.

I have low back pain sometimes from falling backwards off the loading ramp as I was pulling a 5 drawer filing cabinet. I suffered a compression fracture in my L1 or L2 vertibrae along with a ruptured disc. It was very painful and I could hardly move. I could not tie my shoes. It took 2 months at PT to resolve and has never been a problems since.
PT is often more effective than surgery.
I also have a compression fracture in the T1 that attaches to the shoulder. I have several problems with every vertebrae in my neck and at one point lost 50% of motion turning my head. I now have a full range of motion.
I have never had any spinal surgery.
All issues were totally resolved at physical therapy (PT). Get an Rx from an orthopedic surgeon and religiously work at PT and at home using the therapist's recommended exercises.
It will take some time but you will never be sorry that you did it.

 

[sailor man]

The b est source that I have found that deals with a comparison of various motor, loads, gear ratio and speeds is in a GMCWS technical seminar on 10/10/2006. I think that it was mostly written by Chuck Botts with some commentary by Jim Kanomate and Grandpa Billy.

http://www.gmcws.org/Tech/Final_Drive_Ratios.pdf

SO far it is the only comparison that includes a GMC COOP 455 motor. It is limited somewhat because it does not include any data from fuel injection or switch pitch torque converters. I think that it is a vary interesting read even though it is 17 years old.
I am interested in your opinions after you read it.

 

[sailor man]

The best source that I have found that deals with a comparison of various motor, loads, gear ratio and speeds is in a GMCWS technical seminar on 10/10/2006. I think that it was mostly written by Chuck Botts with some commentary by Jim Kanomate and Grandpa Billy.

http://www.gmcws.org/Tech/Final_Drive_Ratios.pdf

SO far it is the only comparison that includes a GMC COOP 455 motor. It is limited somewhat because it does not include any data from fuel injection or switch pitch torque converters. I think that it is a vary interesting read even though it is 17 years old.
I am interested in your opinions after you read it.

I spliced together scaled (2) graphs and spliced them to see how the final drive ratios and the various 455 configurations pan out. It is amazing that the COOP with a 3.7:1 final drive is producing 370 ft-lbs @ 75mph.
Since my coach was already significantly modified before I bought it, I have to find out if there are any changes made to the transmission such as the Caspro Power Drive before I blindly select the 3.7:1 final drive.

http://www.bdub.net/publications/ClascoCatalog1998.pdf

If the Power Drive is installed in the tranny. my 3.21 final drive will actual be 3.66:1 according to Caspro.
I am very strongly inclined to go 3.7:1.

 

[sailor man]

I would like to talk about what I am trying to accomplish by stripping as much as possible to reduce the air drag on my GMC Eleganza II coach.
Just how slippery was the initial GMC motorhome? According to GMC, the wind tunnel test was performed by an independent wind tunnel, not their own. What do these actually use in the wind tunnel and how was it configured?
The reported Air Drag of the test was 0.31. How does that stack up against the competition?
Well as one means of comparison, my front wheel drive 1989 Ford Taurus SHO had a measured air drag of 0.32 and that was pretty good.
If this is accurate, How did they reduce the air drag to that of a pretty decent 4 door sedan?
They made a test model and lucky they made about 8 additional copies of the model for some of the engineers that worked on the GMC motorhome as a retirement gift.
I was fortunate to find a photograph of one given to John G. Locklin and here is a photograph of it!
View attachment 10397
So how close am it getting to the test model?

My roof is almost as clean as this model with the following exceptions:

Pros: Cons
Front & rear bumper covers ZipDee awning on both sides
Bogie cover between read tires Sun shade over windshield
Air dam under front bumper Exterior side mirrors
(15) SunPower semi-flexible solar panels & wire
(pretty flat to the roof with no supporting frame)
Low resistance refrigerator streamline vent
Hopefully out of air stream
HVAC Mini-split heat pump
& Continental tire over rear over rear bumper

Hopefully, this is enough to get my coach very close to the listed 0.31 air drag.
Just how significant is the air drag ratio to how many miles per gal efficiency.

View attachment 10398
I have attached a chart called “GMC Aerodynamic Drag” that I found in the GMCWS technical seminar of 10/10/2006. This data was published by General Motors for a standard 26 feet Motorhome.

Speed Torque HP
40 40 15
55 100 50
70 180 100
80 290 145

When there are storage boxes, skylights, vents, air conditioners, antennas, railings, ladders, rigid solar panels/frames and all kinds of roof mounted items cause a very severe negative impact on the miles per gallon efficiency.
The charts states, “Power to overcome drag grows by the cube of the speed
2 times the speed = 8 x Power
The best payback is to get a much stuff off the roof as possible!

Well, what would my 1976 GMC Eleganza II look like when the solar installation was completed. I was beginning to loose patience, so I bought a damaged Hess Training Van model to mock it up.
I could not put the full size SunPower 110w units in some places because of the various vents that I could not get rid of.
It is a good thing that I have already bought the SunPower panels. There is scuttlebutt that SUnPower may have to go out of business because of the dumping of Chinese panels. Almost all of the semi-flexible solar panels use their very efficient Maxxon solar cals.
I think that it will look very cool and not catch the wind.

 

[GlenC]

My rigid solar panels will go from the front vent to the rear clearance lights. I plan to have a wind deflector to eliminate some drag/turbulence from the elevated solar panels. Top of solar panels should end up about 5" above center of roof.

 

[sailor man]

My rigid solar panels will go from the front vent to the rear clearance lights. I plan to have a wind deflector to eliminate some drag/turbulence from the elevated solar panels. Top of solar panels should end up about 5" above center of roof.

From your comment, I am guessing that you propose to use a member, triangular in cross section in front of the leading edge of the front panel with the pointed end facing forward.
The roof is not flat. It is crowned. I don't know if you are keeping the roof rails or not. If you do, the bases of the roof rails are about 3" below the top of the roof. If the support members are flat, all the way across the roof, there can be an extra 3" of depth to the top of the wind deflector at the ends.
I recommend to use three rows of solar panels, as I do, to help accommodate the solar panels to roof crown. That way it is better to use (3) segmented solar panel rows. Many people use (2) rows and place the long dimensions running side to side. With the (3) rows, the panels are not in the same plane.
The GMC Motorhome is one of the few RVs that have crowned roof and most of the other ones are dead flat.

 

[GlenC]

From your comment, I am guessing that you propose to use a member, triangular in cross section in front of the leading edge of the front panel with the pointed end facing forward.
The roof is not flat. It is crowned. I don't know if you are keeping the roof rails or not. If you do, the bases of the roof rails are about 3" below the top of the roof. If the support members are flat, all the way across the roof, there can be an extra 3" of depth to the top of the wind deflector at the ends.
I recommend to use three rows of solar panels, as I do, to help accommodate the solar panels to roof crown. That way it is better to use (3) segmented solar panel rows. Many people use (2) rows and place the long dimensions running side to side. With the (3) rows, the panels are not in the same plane.
The GMC Motorhome is one of the few RVs that have crowned roof and most of the other ones are dead flat.

I have 4 440W panels and they will sit on 2, 12' aluminum rails that are longitudinal to the coach and mounted on supports at each roof rib. I replaced the rear vent with a Maxxair mini vent and the solar panels bottom surface will sit about 1/2" above the vent The popup shower vent will just clear the bottom of solar panel. I'll probably have the front of the panels an inch lower in front to prevent positive pressure under the panels. The MaxxFan will be moved about 8" forward to clear solar panel. The wind deflector will attach to the front solar panel on each side of the fan and contour to the roof curvature.

 

[sailor man]

This is what the coach looked like when I bought it. The aluminum storage box is really hard edged and very low to the ground.

This is what it will look like with the Thule Transporter Combi storage box. It is much shorter in length and much higher off the ground. Its bottom is above the the bumper while the original box was close to the ground. The through the bumper hitch is about 4" higher.
The old license plate can hardly be seen and I suspect that the box often dragged on the ground.
The new LED strip light above the window provides better protection from the rear and also also flashes as turn signals.
Although this drawing shows the storage box as black, mine has been painter to match the body color of my coach.


The actual bumper to bumper length is about 26'-5", being somewhat longer due to the bumper covers. However, with the added YMGI mini-splits in front of the new continental wheel and Thule storage box, the total length is now about 30'-0".

I have created this drawing to see what my coach would look like is this configuration.
There are two angle lined starting under the rear tire. The upper on is by GMC to determine the the rear road slope clearance when the coach high is in the standard road elevation. The lower lines are for clearance when the coach is fully raised.
Most grounding issues occur at driveway entrance aprons. This configuration appears to clear almost all obstructions.
I suppose that thee may be ample space above the mini-splits, wheel and storage box for a bicycle rack.
The trough the bumper hitch is rated for 15,000 pounds.
I have not yet put the Thule on yet.
The Thule box has an added feature feature. While still attached, it can tilt back to provide added access to the tire and mini-splits. It was designed to allow the rear hatch of an SUV to open while attached and can hold up to 350 lbs of stuff. It certainly is very accessible and many people admired it when we traveled with it on the back of our C-Max.
Of course, I may choose to drag my silver Ford C-Max Energi instead with the Thule box on its own hitch.
I also have (2) Thule Hullavator roof racks for my (2) Hobi kyacks to fasten on the toad's roof.
The Hullavator gas springs can lift amp to a 45 lb boat to roof position by itself with no human effort.

 

[sailor man]

I have 4 440W panels and they will sit on 2, 12' aluminum rails that are longitudinal to the coach and mounted on supports at each roof rib. I replaced the rear vent with a Maxxair mini vent and the solar panels bottom surface will sit about 1/2" above the vent The popup shower vent will just clear the bottom of solar panel. I'll probably have the front of the panels an inch lower in front to prevent positive pressure under the panels. The MaxxFan will be moved about 8" forward to clear solar panel. The wind deflector will attach to the front solar panel on each side of the fan and contour to the roof curvature.

View attachment 10470View attachment 10472

There are few rigid 440W solar panels. Are you using the LG NeON R LG440QAC-A6 440W solar panels? If so, they are 41.0" x 71.2" x 1.57" and 45 lbs. each.
If you are using two linear aluminum support. there are 10 fastening points to the coach frame in total. At speed, you are close to Cat 1 wind forces with considerable uplift.
I would consider using well nuts to fasten the supports to the roof. If there is physical space I would use (2) fasteners at at every fastening point. The well nuts have the advantage of being waterproof and are much stronger than using taping screws.
On my installation, I am using (6) well nuts for every solar panel in conjunction with industrial strength velcro.
Please calculate what the upload forces will be and size the fasteners appropriately.

It also appears that you eliminating the linear vent above the refrigerator compartment.

Your installation is 1,760 watts and mine is 1,470 watts. What have to done to reduce the electrical consumption and how much battery capacity do you have? Also, have you changed the alternator and will you still have a generator?

 

[GlenC]

There are few rigid 440W solar panels. Are you using the LG NeON R LG440QAC-A6 440W solar panels? If so, they are 41.0" x 71.2" x 1.57" and 45 lbs. each.
If you are using two linear aluminum support. there are 10 fastening points to the coach frame in total. At speed, you are close to Cat 1 wind forces with considerable uplift.
I would consider using well nuts to fasten the supports to the roof. If there is physical space I would use (2) fasteners at at every fastening point. The well nuts have the advantage of being waterproof and are much stronger than using taping screws.
On my installation, I am using (6) well nuts for every solar panel in conjunction with industrial strength velcro.
Please calculate what the upload forces will be and size the fasteners appropriately.

It also appears that you eliminating the linear vent above the refrigerator compartment.

Your installation is 1,760 watts and mine is 1,470 watts. What have to done to reduce the electrical consumption and how much battery capacity do you have? Also, have you changed the alternator and will you still have a generator?

Yes, I got the LG440QAC-A6 before they were discontinued. ($1.11/W) which was a good deal a few years ago.
I hope to minimize the panel uplift with installation and possibly side skirts. For mounting, I will attach aluminum angle at 10 points with 3M5200 and a bolt/nut through the rib. 10 - 1/4-20 SS bolts will handle 2,000lbs each.
I'm planning on an Isotherm 12V refrigerator, so don't need the vent.
I have 10,752Wh battery. I can carry my Honda EU2000i generator. Plan to get a Orion XS 12-12V 50A DC-DC converter for the standard alternator. Propane and Onan are out!

 

[sailor man]

I recommend installing an Isotherm Intelligent Temperature Control (ITC) on all Isotherm refrigeration products. It controls the dc motor speed and significantly further reduces the energy use of these refrigeration products. I have attached a .pdf file of the ITC control.
On my coach, I have installed a handheld shower+controls and a tankless lpg hot water heater, so I still need the roof vent.
Since the Isotherm refrigerators are so much less deep, there is additional space for various components behind the frig that are accessible from the exterior.
I also recommend that Isotherm frig and/or freezer normally do not completely fill the space in the cabinet and sheets of polyisonerate can fill the open spaces to further insulate the refrigerated equipment.

 

[GlenC]

I recommend installing an Isotherm Intelligent Temperature Control (ITC) on all Isotherm refrigeration products. It controls the dc motor speed and significantly further reduces the energy use of these refrigeration products. I have attached a .pdf file of the ITC control.
On my coach, I have installed a handheld shower+controls and a tankless lpg hot water heater, so I still need the roof vent.
Since the Isotherm refrigerators are so much less deep, there is additional space for various components behind the frig that are accessible from the exterior.
I also recommend that Isotherm frig and/or freezer normally do not completely fill the space in the cabinet and sheets of polyisonerate can fill the open spaces to further insulate the refrigerated equipment.

Totally agree, I'm looking at the dual compressor fridge/freezer and the ITC. Since I'm making all new cabinets, I do plan to insulate the fridge/freezer (except where ventilation is needed) with the polyisocyanurate rigid foam panels, which should also help reduce energy usage.

 

[odintech]

There is nothing wrong with the radiator that is in the coach now. I wonder if I could just buy the dual fan and controller and find a way to match them with the existing radiator.

I saw a YouTube video recently that a Hyundai sorrento electric fan nearly matches up with the original radiator, that might work for your desired fan setup.