Civic VX MPG project (Delete Alternator, add solar)
 

After a year of searching, I found a 1994 Honda Civic VX (49state) to base my project on so let the fun begin!

As the title suggests, I plan on using a solar system from SunRNR.com to allow for the removal of charging system losses. This solar system is cool because it uses a 135Watt solar panel hooked to a small battery unit. The SunRNR unit has a built in 12VDC charge controller and power invertor to supply 120VAC.
Heavy gauge power cables will connect the rear mounted SunRNR battery pack in parallel to the stock car battery and electrical system. I anticipate that removing the alternator belt and charging losses will result in sufficient gain in MPG to quickly pay for the SunRNR unit and more.

The SunRNR solar panel has a very sturdy aluminum frame which reduces the chances of damaging the panel and should allow for easy integration into a boat tail addition. It looks like the best mount will use the existing upper rear hatch hinges to make the solar panel into a new hatch. I'll upgrade the hatch support struts to hold the extra weight which will make it a functional trunk lid. Initially I'll be building the boat tail out of foam for easy shaping and aerodynamic testing. The outside will then be clad in a skin of fiberglass or aluminum and the trunk will be hollowed out leaving a layer of foam which gets fiberglass. (EDIT: The solar panel fit better on the top of the car)

Sounds ambitious, but doable. You will find others on this site who have first hand knowledge with a boat tail add on.
I have a 15w panel on my dash that keeps keeps my battery at full charge, which is useful as my cars factory alarm and various components such as ecu ect.. slowly drain off my battery noticeable without the panel in place.
I leave my car for days at a time without driving it.

Vehicle Details:
1994 Honda Civic VX Hatchback (5-wire 49state model)
Stock 1.5L VTEC-E engine with lean burn - 130k miles
Aztec Green Perl exterior with black/gray interior

The previous owner replaced the distributor and plug wires but I didn't know any other vehicle history so I went through the entire vehicle.

Initial Work Completed:

New low rolling resistance 165/70-R13 tires
New Bosch 5-wire wideband oxygen sensor
Timing belt replaced(corrected incorrect valve timing)
Ignition timing set to 16deg BTDC
Thermostat replaced
Valve adjustment
Spark plugs replaced
Fuel filter replaced
Alternator belt replaced
Oil pan gasket
Clean EGR
Clean FITV
Clean air filter
PCV checked
Remove aluminum exhaust shield
Exhaust system heat wrapped
New exhaust gaskets
Rust spots fixed
Fresh 5W-30 Mobil 1 Synthetic (will use 0W-20 next time)
FRAM extra-guard oil filter

I also added air conditioning from salvaged parts

Quite a list. The solar system sound cool too. I'll look it up. What are you using for the internal antenna?

Welcome to the forum! Subscribed to this project.

Have you done the math on the solar payback time? How much does the panel/battery combo cost?

The radio antenna is a cheap ebay unit that is adequate but I wouldn't necessarily recommend.

The payback period of the solar system depends totally on the mpg change and current fuel prices but I put it at less than 150,000 miles if I gain a few mpg. Depending on how the unit works, I may also try using an electric motor to turn the air conditioning pump to eliminate those losses.

5/30/12 Project Progress:
Increased the ignition advance to 18deg BTDC

Mounting the SunRNR power unit
Using a large hammer, I made room for the SunRNR to sit inside the spare tire well. It is my hope that placing the unit lower to decrease the effect of it's weight on performance as well reduce the space loss.
(EDIT: I ended up taking the unit apart and mounted the battery behind the drivers seat)

More about the SunRNR:
Charger controller

12VDC - 30amp capacity
Multiple input formats (solar, windmill, 12VDC)

Inverter

Input 12VDC
Output 25.5 Amp @ 120VAC = 3060W

Huge Deep Cycle Battery Manufacturer Specs

1100 Cold Cranking Amps
210 Amp Hours
Valve Regulated
Absorbed Glass Mat (AGM) Technology
Lead Acid

https://lh5.googleusercontent.com/-B...725_192112.jpg

Solar Panel 135W

https://lh3.googleusercontent.com/-J...olar-Panel.jpg

I like the idea of solar assist, however the cost seems extreme.
Can you please give a link to the specific unit your using.
Also just a personal choice .. I run Mobil 1 Synthetic 0/20 in the winter and 5/20 in the summer, I would wager that unless your VX is spewing oil, all your doing is killing your potential MPG with the heavy oil.
I would never run a Fram filter .. Wix is the way to go.

Added this to the solar assist wiki forum links.

Solar 12v assist - EcoModder

I mounted the SunRNR solar panel to the roof of the VX using stainless steel brackets riveted to the roof.
https://lh5.googleusercontent.com/-9...626_195126.jpg

https://lh6.googleusercontent.com/-r...626_194903.jpg

https://lh3.googleusercontent.com/-C...626_194940.jpg

Have you tried it without the alternator? I am wondering if 130 watts is enough without the alt. I am running a 40 watt solar panel inside my car and it really seems to help hold the battery at a topped up level, saving gas by running the alt way less.

I added some side skirts to the panel.
https://lh3.googleusercontent.com/-k...0" width="640"

3rd Brake light is mounted to the tail of the panel for now. It will be integrated into an aerodynamic tail section as time allows.
https://lh3.googleusercontent.com/-V...0" width="640"

Welded up a battery box which will be mounted in the spare tire well.(EDIT: Ended up mounted behind drivers seat)
https://lh6.googleusercontent.com/-7...0" width="640"

I really like the effort, and I hope it produces enough power to have a significant impact. I have an idea, looking at your snaps. Is the angle of the panel off "the template" a little? If it is I bet you can adjust it fairly easily. Then maybe this is a nice opportunity to build a kamm back, consolidating a gain. I wonder if the over-hang out the back is increasing drag for you. Have you considered a kamm?

Looks better with closed in sides, can you please take a pic with the hatch open.
I think if the hatch opens enough, then a solid none moving kamback could be easier to make, and possibly more effective as well.

Here it is with the hatch open
https://lh4.googleusercontent.com/-1...0" width="640"

https://lh5.googleusercontent.com/-N...703_174435.jpg

https://lh4.googleusercontent.com/-o...703_174507.jpg

I plan to increase the rear angle and create a kamm back soon. For now, more open hatch area will be very helpful while installing the new 110# battery pack which should be here soon.

Today, I removed the alternator charge wire for testing. The panel seems to put out enough to run the car with little to no battery discharge.

Xenon HID 35W headlamps installed to reduce light load

That is a serious solar panel. It must put out 5 or10 amps on a sunny day. If your car uses 10 amps to run , lets say your panel is putting out 6 amps, your battery would only have to carry 4 amps. 4 amps an hour is not going to drain the battery. I have complete faith in your Solar charging system. Adding some high output led spot lights flush to the grill block would be a nice feature. One that i plan on doing to my Beetle. Its headlights are weak and suck amps.

It was time to make the car a solid color. This army green is more suitable.
https://lh6.googleusercontent.com/-k...725_191938.jpg
I built the side skirts and front lip for less than $20 worth of Coroplastic from Creative Press sign shop in Ruckersville Virginia.

The car wasn't lowered at all but looks very low. The coroplastic front lip will bend out of the way when it hits stuff so I made it pretty low.
https://lh4.googleusercontent.com/--...725_191956.jpg

very nice

Deep Cycle Battery Installed
 

I finally got the large deep cycle battery installed. The charge controller is now right behind the Emergency Brake so I can see it from the drivers seat. Under the charge controller is a fuse block to help prevent a fire.
https://lh5.googleusercontent.com/-l...725_192056.jpg
https://lh5.googleusercontent.com/-B...725_192112.jpg

The car is looking good! This will likely work to reduce your overall drag, from what I have read here. I had an airdam that low and it got banged-up noticeably quite quickly. If you have speed bumps or deep dips like I do, it'll happen to you too, likely. I now have a new dam and side skirts and I stay a little further off the pavement.

How many amp hours will that one give you, and how are you charging it? Just the panel? You have it well secured and vented?

The battery is rated at 210Ahr.

This project is just starting the testing phase. I disconnected the alternator wire and it is only using solar to charge. Hooking a charger to it at night is an option.

The battery and box are well secured with two ratchet straps.
The Valve Regulated Absorbed Glass Mat battery is meant for confined area's with poor venting and is currently vented directly to the cabin.

Wow!

I hope I can be some help for the plan/testing, having had a deep cycle battery and alt delete running for almost a year. So my questions are in that spirit: Won't a 210 ahr battery need at least a 90amp charger or an equally powerful alternator to get a true full charge? With less, won't the battery degrade in its ahr capacity kinda quickly?

SunRNR has done a lot of research on this combo of solar panel, charge controller, and battery. I trust that their system will hold up well.

Quote: California98Civic
Won't a 210 ahr battery need at least a 90amp charger or an equally powerful alternator to get a true full charge? With less, won't the battery degrade in its ahr capacity kinda quickly?
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I have not heard/ read about ah losses due to low amp charging.
I am still under the belief that slow/ low amp charging is superior to fast / large amp charging. In short the fast charge is reported to dissipate faster.
Could you enlighten me with some information or a link ?
I seem to have a gap in my knowledge bank.

Charging batteries fast wares them out like discharging them fast.

Charge them as slowly as you can get away with.

Here's the content of my conversations with the Odyssey factory people, the three substantive calls with Bruce (plant manager) about my charging strategy, my alt on/off switch, and my driving pattern. He recommended a 25amp charger--instead of their 6amp charger--because the lower amp charger on the 40 amp hour battery I bought will not, long term, be able to fully charge the battery even if I only discharge 20%-25%. Over time, sulfation builds up more quickly and cannot be as easily corrected by the charger. It also cannot be rectified by the alternator, which has modestly too low voltage for effective charging of a 40ahr deep cycle battery. He also recommended I modify or swap my alternator for either higher voltage (to 14.7 or so instead of 14.3) or higher amperage (from 40 to maybe 70 or 90). The latter is only if I cannot have the alt modified for higher voltage. He told me about a rule of thumb he applies: assuming appropriate charging voltage up around 14.7, then the charger should be rated for amperage not less than 40% the amp hour rating of the battery. Lastly, the 25amp charger has three stages: charging, "finishing," and float, which apparently means different amounts of current and voltage.

Probably most things are debatable, so what do you think might be wrong, partly or entirely, in that set of recommendations?

This road trip was 400 miles of hills in cloudy and rain. I didn't let the voltage go below 11 volts to prevent damage to the standard car battery. The results were impressive as I only had to run the alternator for 30min to charge the system before parking the car for the night. Olive averaged around 55mpg at 70mph on I-81 in Virginia which is mostly mountain driving.

California98civic

I think the 25 amp charger will knock the sulfation off the plates as well, also it may be useful with a battery to have a high amp charge if it needs to be fast charged before being put back in duty, much like the alternators do to our conventional car batteries.
Trickle chargers are for low duty maintenance , a high amp charger is more of a necessity with high drain battery systems.

I have read that you can change the voltage regulator instead of the alternator.

Results Are In
 

With 5000+ miles of testing on consistent routes, the results of this experiment are in.

The alternator belt was NOT removed.

Running the entire electrical system on only the solar system resulted in statistically insignificant mileage increase. (not expected):confused:

Ouch!

Since we know taking the electrical/alternator load off the engine is absolutely going to save fuel, I would say those savings were off-set by increasing other loads:

1) the weight of the solar/battery system (probably a relatively small impact), plus,

2) the added aerodynamic load of the panel mounted on the roof which increased frontal area (A) and drag coefficient, (Cd).

Aero losses were probably a relatively larger impact compared to the weight gain.

It's discouraging to do all that work and not see the effect you were hoping for (been there, done that!).

Thanks for reporting unexpected results though. It'll help the next person considering this type of mod.

Agree completely with Metro, and also want to thank you for writing in the results even though they were frustrating to you. Much integrity in that and very helpful to the community as a result. I'm sorry the mod didn't work.

Try this mod with the belt off the alternator.

With my suburban 100w should only make a difference of about 0.1mpg, which is impossible to track. I am going to guess a car that gets twice the fuel milage of my truck would see about twice that milage increase.

+1

It is just as important to report negative results as positive results.

The idea is good, though. My opinion: Your solar panels are much larger than you need given the size of your deep cycle battery. I suggest looking for thin film panels that could be glued to the original top of the car. That would maintain the original aerodynamics.

You said connecting a charger to the battery was optional, however have you tried precharging the battery since taking ownership or checking its current SOC?

Have you tried charging the battery before driving the vehicle?

Hondas have something that turns the alternator off and on as needed to aid in mpg, its called an ELD. Having said that, myself and a few Insight owners have noticed a signnificant increase in mpg whe precharging the 12 volt battery before driving on short vs long trips. After 7 miles or so the charge is worn off and mpg starts todecline vs increase.

For the Insight it cuts on the charging of the 12 volt battery when the power falls before 12.5 volts and off when it hits like 14.5 volts.

If you consider this a fail, get yourself a grid tie inverter and use it to supplement your power needs in your home. I have 6 panels and 2 converters and they save me 50 bucks a month on my power bill. :thumbup:

Or if you like, Ill take the panel off your hands. You anywhere near 288 and Hull St?

I agree withthe math above - My HX with alt delete does seem to need about 10A to run the car, as long as I'm not running headlights or fans. Headlights take another 10-12 amps.

I like this project. Nice job. I'm concerned about the aero losses from the roof panel but you may be improving that situation.

4A draw (after adding in the 6A from the solar charger) won't have much effect on your large deep cycle battery's state of charge, if you only do that for an hour or two. However if you've read into these batteries' behavior, you already know they last longest if kept well charged up. So top it off if you draw down more than 5-10 amps, is my advice. If you can top it off daily that's nice but I wouldn't go, say, a week, drawing it down 50A or more, and then recharge on weekends. If you want it to have a long life, recharge more often than that.

Kudos for building it with a large deep cycle. Mine is also pretty large, a Group 29 from WalMart; I estimate it at about 100AH by standard measurement. Enough to do the job without getting drained down much.