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Don't laugh yet!


IMPORTANT NOTE: All thoughts here are just conceptual. Some of them would likely void your warranty, or could cause damage to your car. Tampering with the NIMH batteries is dangerous. The purpose of exploring this topic is to devlop ideas. Often, bad ideas end up producing great results after proper thought, modification, evolution and innovation. Hopefully, in the end, a well organized, safe, benefit-yielding design can be made.....maybe not! We will see! Please don't harm your car or yourself with premature ill-conceived ideas yet to be thought out. Over time, I would like to develop a well conceived plan that takes all factors into consideration -- safe, non-warranty-voiding, and a productive addition the Insight.

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Background: I have a 2004 CVT. Here are some observations I have made since purchasing it. I think some of these observations are different for 5 speeds. My solar thoughts appear later, and are based upon these observations.

Battery
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(1) My battery never fully charges. It is at 2 bars below max 95% of the time! In the other 5 percent of the time, it is 3 bars less than max -- never lower. This is obviously a unique characteristic of the CVT and possibly newer software in the 2004 model.

IMA
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(1) IMA assist (the way I drive) is never more than 4 or 5 bars. In order to get more, I would have to drive like a maniac. When flooring the gas pedal, it goes several bars higher, but simultaneously the MPG goes below 10 MPG. Therefore, I feel I am better off with 4-5 bars assist and "learning to like it" (gets about 25-50 MPG when using 4-5 bars assist in highway driving). I get 4-5 bars assist in City driving too (more if I lay rubber when pulling out!)
(2) The ASSIST always stops assisting before I am finished accelerating -- both highway and city ... this is very frustrating.

I often wonder if a contributing factor as to why CVT's get poorer MPG is due to the restrictions on how and when assist is applied. I know everybody attributes the primary difference to the lack of lean-burn, but I am not so sure. Perhaps restricted assist is 1/2 the reason, and lean-burn is the other half.

Momentum REGEN - Highway Driving
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(1) 4-5 bars assist is very helpful on inclines
(2) On descents, I get 4-5 bars (green) battery charge
(3) The 4-5 bars charging on descents SLOWS DOWN THE CAR BADLY!
(4) I often have to apply pressure to the gas pedal on descents in order to stop it from charging the battery in order to maintain spped DOWNHILL. Using the vehicles power resources to travel down slopes on the highway doesn't make any sense to me. It makes sense when you want to slow down, but that is almost never the case traveling on the highway. But, that's the way it is designed. Remember -- I got a CVT. I owned a stick all my life prior to the Insight. With a stick, putting it in neutral, yields far less resistance on descents than automatics; you just can't 'coast' like you do with a stick. ASSIST complicates this even further creating a real problem looking for a solution.
(5) On ONE (just one!) occasion my battery was fully charged. it coasted very nicely on descents ... it was a real pleasure to drive! As a rsult, I got significantly better mileage because the car did not engage regen, and therefore DOES NOT SLOW DOWN THE CAR!

Momentum REGEN - City Driving
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(1) When I take my foot off the gas pedal in City driving, 95% of the time I do so with the intent to slow down. In the city, momentum charging is helpful for both purposes -- slowing down, and charging the NIMH's.

REGEN -- From the brakes
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(1) I can't detect any slow-down whatsoever from brake electrical regeneration. When extreme light pressure applied to the brake pedal, I often get about 10 bars! I can't feel any difference (slow down effect) between (a) momentum regen alone and (b) combined momentum and brake regen. The mod I saw on a thread in this message board to activate brake regen with a button seems like a good idea!

SUMMARY -- AND IMPORTANT OTHER CONSIDERATIONS
====================================
(1) Momentum REGEN is costing me MPG on highway driving (on descents)
(2) Fully charged battery saves me MPG (and frustration) by not having to apply gas pedal going downhill!
(3) Boston, MA climate can be extremely cold during winter
(4) Extreme cold bad on battery system?
(5) MPG suffers badly from cold and extreme cold engine starts
(6) MPG suffers from continued cold engine temps while driving
(7) Extreme hot interior temp is bad on battery during summer?
(8) Extreme hot interior temp is bad on me during summer!
(9) 12V battery draws power from main system to recharge itself, thereby reducing the potential for full-charge-state of main battery.
(10) Having a fully charged battery system each time you drive it (both 12V and NIMH) would be great!

THE FANTASY BEGINS?
===============
(1) Cover/replace the entire roof of the car with a large solar panel, or panel array. It could be supplemented with more solar panels in other places, but my thought is to not make this thing look like a science project -- keep it's rather distinguished appearance by making the roof panel(s) neatly designed, packaged, etc. -- make it look as good as it can. Note: My idea to use the entire roof for solar panels is a result of posts from other threads suggesting only trivial power can be generated by smaller panels. If this proves untrue, a less dramatic solar system would be used. People smarter than I can hopefully aid in this aspect of the design. Also, smaller panels could be used if a more effecient application of available energy were to be developed thereby reducing the need for additional power.
(2) Acquire a hand-held pocket-pc or palm computer (lowest power consumption possible, minimal RAM, etc.)
(3) Acquire or create a panel controller to connect the panels to the NIMH batteries -- it has to prevent overcharging (of course!), and have a diode to cut off the circuit during non charging time periods. Since the NIMH batteries charge the 12V battery, I don't think it would help to attempt connecting to the 12V for charging purposes (redundant?)
(4) Install exhaust/intake fans on cargo area air vents as described in other threads. Computer would compare indoor/outdoor temps to determine when fans are needed, and only run when needed. The fans move air bidirectionally depending on circumstances. The computer could detect when little or no further benefit could be achieved by running the fans for additional time, and shut them off in order to devote electric resource to some other system.
(5) Install 3 liter thermos to connect to coolant system to help increase engine temp when car not in use, or help heat it while driving during extremely cold temps where desired engine temp can not be maintained. (This was a mod proposal/thought from another thread).
(6) This one might be a bit extreme! Install an electric blind on the rear window. (The purpose of which would be to enable unobstructed vision while driving, yet could be controlled to block sunlight while the vehicle is not in use (to keep interior cooler during summer, and possibly keep it warmer by acting as an isolator during the winter by automatically closing it when car is turned off. During winter, if the computer detects that the outside temperature is higher than the inside temperature, it would open the blinds. Otherwise, it would close them -- 24 hours a day -- all automatic. (Cooling fans could act as both heating and cooling with some added smarts, and would operate in a similar fashion)
(7) install a set of sensors (a) Interior temp, (b) exterior temp, (c) coolant system temp, (d) daylight sensor, (e) car-in-use may not need a sensor since I suppose you could connect to the cig lighter wiring, and detected the presence or absence of current, thereby indicating verhicle in/out of use.
(8) Install a thermal resistance heater someplace in the car for interior comfort.
(9) (NEW) Add a series of peltier thermoelectric device and develop some type of indoor/outdoor thermal transfer system to cool and heat the interior of the car. These devices are used in coolers that plug into your cig lighter adapter. This idea was mentioned in a couple of other threads on this forum. Clearly, they won't cool and heat very much, but every little bit helps. The "every little bit helps" concept is proven by the Insight's design --- Honda apparently measured every nut and bolt that went into the Insight to produce an 1850 pound car. It appears to have been accomplished by taking advantage of every savings possible. Each on their own may be trivial. However, when considered as an aggregate total, trivial savings can be significant.

IMPLEMNTATION
==========

All of the sensors would be connected to the hand-held. The loads would have to be connected to some type of controller which would interface to the handheld to allow the handheld to programatically turn each attached load on or off.

All the computer has to do is (a) be programmed, (b) be able to read input from sensors, and (c) turn on and off 12v DC loads.

THe computer would operate (unattended) on a 24 hour basis. When the software detects low charge on handheld battery, it would shut itself off (or perhaps hynbernate) and disenable all attached loads and power sources. It might be a thought to attach a private backup power source (perhaps an array of D size NIMH's) to the handheld to allow it to operate for entended periods of time when external charging is not available. (Of course another option would be to implement this system with a programmable controller (chip) for very extremely low power consumption -- more difficult to build!)

Other than an obvious mod to the roof, this system needs to be minimally invasive (if at all) to the "stock" function and operation of the vehicle. Warranties must be protected, and it must be safe to install. This is important to me, as I really don't want to redesign or change the way the car was designed to operate in any way (In other words, I am don't want a mod that simply "tricks" or "fools" the system into doing one thing when it was designed to do another. As an example, I would not want to install a regen-cutoff-switch, or a i-didn't-let-up-off-the-gas-pedal button to fool the Insight's systems into doing one thing when it really should have done another -- and thereby damage the system.

SOFTWARE Fantasy
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I'm a software developer by profession, so this part seems the easiest to me.

The overall purpose and design of the software would be to manage all resources as appropriate ... as needed, as available -- on a 24 hour a day basis. It would turn systems off when generated electricity is not available, and distribute them based on a needs-based criteria when they are available.

I would develop a desktop based application with a friendly user interface to configure/program the handheld. It would likely use a Compact Flash or SD memory card to allow me to easily transport it back and forth from the car, and allow easy reconfiguration.

The computer would allow you to monitor the environment, and make intelligent decisions as to how generated electricity could best be spent.

During the cold: (a) you might want to focus on engine temp while car is parked. (b) you might want to focus on NIMH charging while driving, or (c) perhaps interior heat. During cold, once computer detects NIMH battery is fully charged, it could then switch from the NIMH charging load to interior heat, or perhaps engine coolant heater.

During summer: (a) while parked, you might want it to concentrate on NIMH charging and once it detects full-charged state, switch to interior temp reduction. Or (b) perhaps, you might want it to split the electrical resource between interior temp reduction AND NIMH charging (not by running them both at the same time, but by programatically splitting the amount of time devoted to each load). Or, (c) it could turn off the other loads for a few seconds, and adjust the rear electric blind such that the sun is blocked.

In other words, make it smart. Another possible enhancement would be to add voice recognition to the handheld, and have it give audial beeps and/or computer generated voice status reports. The "magic" of the system would like in the computer and software. With the hardware in place as described, the features of the software are only limited by your imagination.

LOGGING DEVICE
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THe handheld could be used as a logging device to measure how successfully different systems perform. As an example, while using the coolant heater, it could log coolant temperature in 5 minute intervals over an extended period of time. This would provide you with precise knowledge of how each system preforms given environmental considerations With this data, you could then better configure the software to allocate energy resources. Overall system effeciency could be tightly managed. The log could easily be examined on your in-home computer.

802.11b or BLUETOOTH
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I already own an HP 5555 Pocket-PC. It accepts SD memory cards, Compact Flash. It also has built-in 802.11b as well as Bluetooth. For long term use, it has way too many features needed for this application. However, I would likely start with it with the intention of replacing it later with something smaller and less power consuming.

With wireless capability, however, I could have the pocket-pc log performance data directly (remotely) to my indoor desktop PC. Also, I could reconfigure it wirelessly without having to run outside. This would allow me to study how well different heating/cooling systems work, and easily make changes to test lots of different configurations. The intent here would be to optimize the Solar systems resources to achieve the greatest return.


SOLAR PROPULSION?
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I started with "Solar Propulsion". If this idea could make a car able to (on average) move from point A to point B with improved MPG, would it qualify as "Solar Propulsion?"

Solar charging the NIMH's while driving would give me a better chance of reach ing full power -- something it has only done once since I have owned it. Again, full charge means no descent slow-downs from regen charging --- improved MPG! Also, Higher engine temps in the winter helps propel the car more efficiently. Coolant engine heating would help while parked (for startups), and keep it warmer while driving -- both helping MPG.

CONCLUSION
=========

It is true – solar panels can’t create large quantities of electricity on demand. They can, however, produce large amounts over extended periods of time (for example, while the car is parked in the parking lot, and you are inside working for 8 or more hours).

Based on the input from many of you in other posts, it became clear that solar power is a limited resource. So, I decided to focus on how to find the best possible application of a limited resource to produce a greater benefit (and also, to intelligently direct that resource to the most immediate need!)

Ok, so have I really lost it? Need to be committed? or What? I have decided not to show this document to my wife. Reasons should be obvious.

This would obviously take some time to implement -- probably more design and planning than actual installation. While I have the software skills, I lack in the required hardware skills. Also, I lack other knowledge dealing with electricity and solar power generation.

I would welcome any ideas, suggestions, problem identification, and knowledge, anybody might be willing to contribute to this exploration.
 

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I don't think you would need as much in the way of solar panels as you have proposed, but they could definately be used to charge the battery. One important note, however, is that you should find a way to route the power from the solar panels through the battery controller. The battery controller doesn't actually measure the charge in the battery, but rather keeps a running tally based on current flow in either direction through the battery controller.

Also, the battery normally only charges to 80% of it's capacity, and discharges to 20% of it's capacity. (The guage is adjusted to compensate for this, so "no charge" is actually 20% charge and "full" is 80% charge.) Limiting the cycle like this preserves the life of the battery. So this is another reason why you should route through the battery controller.
 

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Since you asked for opinions:

I don't mean to sound negative but, a primary consideration you are overlooking is keeping the batteries "happy". Not too full nor too empty and during charging, not too hot nor too cold. Failure to correctly account for these paramenters will severely shorten battery life.

Also if you do the "math" in regard to the amount of energy useable from a solar array and the mere seconds of engine operation that it equates to you will see the very limited return on your investment. And don't forget the weather and "efficency" losses.

Using solar for cooling (ventalation) of the interior in the summer is a better inventment.

The hot air mod and the cool temperature radiator block along with driving in the high MPG style are simple proven methods that are _very_ cost effective.

See:

http://www.insightcentral.net/forum/vie ... fdd3075a64

For more thatn you probably want to know about the IMA pack.

HTH!
 

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Don, I've been a solar enthusiast for decades, building a model solar car before the official solar races started and more recently a one man solar boat. As a technologist with a background in power conversion I'd love to see something done with our cars.
 

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Discussion Starter #5
Thanks for the comments Trekker... Actually, I am seeking the negatives regarding this thought! Any you may have are welcome! I view negatives as "problems which have yet to have found their appropriate solution". If something is a bad idea ... PLEASE LET ME KNOW!

You mentioned:

Insightful Trekker said:
I don't mean to sound negative but, a primary consideration you are overlooking is keeping the batteries "happy". Not too full nor too empty and during charging, not too hot nor too cold. Failure to correctly account for these paramenters will severely shorten battery life.
In my original post, item #3 under "The Fantasy Begins?" reads:

(3) Acquire or create a panel controller to connect the panels to the NIMH batteries -- it has to prevent overcharging (of course!), and have a diode to cut off the circuit during non charging time periods. Since the NIMH batteries charge the 12V battery, I don't think it would help to attempt connecting to the 12V for charging purposes (redundant?)

Foxpaw noted I should investigate using the vehicle's battery controller -- a good suggestion. I will have to find out if it requires power of it's own to function, and if so how much. If it has to be "powered up" to work, maybe topping off the batteries only while driving could be something to look at. I have a good bit to learn about charging NIMH's -- Foxpaw's point of counting instead of measuring would have to impact the design. His idea would clearly be a great solution for keep the battery "happy" -- better than the one I proposed in item #3.

With regard to how much propulsion I would get from extended solar charging ... my purpose is to "top off" the batteries in order to avoid regen on descents. It's not to propel the car directly any distance at all. Clearly, though, I need to investigate how much power it would take to charge the NIMH's (for example) from 75% to 80% capacity given available solar energy as a function of time. From what I know so far, I get the sense that the NIMH's don't hold a large amount of electricity as it is. My though was that "topping them off" might be something to look at.

I guess my thinking is this .... If I invest in solar panels to drive 12v fans during the summer, do I just let them lie there and do nothing all spring, fall, and winter long? It's a fascinating line of thought ... fun to think about!
 

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DonWatson3558 said:
<snip>

With regard to how much propulsion I would get from extended solar charging ... my purpose is to "top off" the batteries in order to avoid regen on descents.
If I am understanding your terminology correctly "regen on decents" would equate to "charging on deceleration". Which is almost "free" in that the car's momentum is slowing for some reason. Why not convert some of the energy to electricity?

The bigger loss is that of a forced charge event which is due to depleting the batteries on acceleration faster than is recharged on deceleration or braking. Power is drawn directly from the ICE (Internal Combustion Engine) during this type of charging event.

But if you've got a CVT (automatic) Insight then the above "rule" doesn't apply. A CVT equipped Insight allows for an additional dimension of battery happiness in that the ICE's RPM will be infinitely adjusted in balance with IMA assist or charging. Which adds flexibility in battery thermal and load management. Forced charging events are virtually "transparent" to the driver (for most situations). In any case a CVT forced charge and a 5spd event are very different animals from behind the wheel. My understanding from postings and exchanges with several CVT owners is that they have never experienced a forced charge. See my old post link as referenced in my earlier reply.

And to reiterate: charging a NiMH battery when its too cold will cause damage. The Insight's battery management uses thermo sensors to determine just how to treat the batteries according to their temperature. A much more sophisticated system than a diode.

HTH!
 

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Discussion Starter #7
Insightful Trekker said:
If I am understanding your terminology correctly "regen on decents" would equate to "charging on deceleration". Which is almost "free" in that the car's momentum is slowing for some reason. Why not convert some of the energy to electricity?
Trekker -- that's precisely my point. With my CVT, charging on decererations during highway driving is not free. It costs! I have to apply the gas pedal (pulling power from available energy sources) to get down the descent! The "some reason" you mentioned is because it has incorrectly assumed that my intention is to slow down rather than continuing foward.

My "real intention" only happens when the battery is fully charged. I can drive on the highway the way one would expect to drive on a highway. Up and down small slopes without the car assuming I want to stop -- and then applying the momentum regen "brakes".

It even goes into regen on very mild descents when I let up on the gas pedal slightly! (I let up on it trying to coast a little or increase MPG, but the darn thing forces me to put the pedal back down. I get the sense that 5 speed drivers don't suffer from this problem.

If the batteries were charged to full (80%), I could go down a descent normally during highway driving. Clearly, the car MUST regen if when (if ever) the batteries are low -- so the basic design of the system can not be mofified. The only option is to improve the chances that the NIMH's are fully charged, thereby providing the opportunity for non-regen descents to occur.

Solar enhancement to charging the battery is not a total solution, but my thought was that it would at least increase-the-ever-rare-occurance of getting down hills avoiding regen. I get the sense 5 speed drivers don't suffer from this problem. BTW, I have only had a full-charged state once since I bought it.

Insightful Trekker said:
The bigger loss is that of a forced charge event which is due to depleting the batteries on acceleration faster than is recharged on deceleration or braking. ..... But if you've got a CVT (automatic) Insight then the above "rule" doesn't apply.
I noticed that. I read your thread and didn't identify with much of what was said due to differences with CVT. Also, I don't think I could deplete the batteries if I tried. I am at 2 bars below full 95+ percent of the time. The other 5- percent is at 3 bars below full.

Insightful Trekker said:
And to reiterate: charging a NiMH battery when its too cold will cause damage. The Insight's battery management uses thermo sensors to determine just how to treat the batteries according to their temperature. A much more sophisticated system than a diode.
Yes, I clearly learned something important here. As both you and Foxpaw have stated, any added charging capacity to the system must use the NIMH's battery controller with all it's built in safeguards.

Thanks again for all the comments!
 
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Hi Donwatson3558:

___As Insightful Trekker has already mentioned, the energy output of a roof full of solar cells is so small as to be almost meaningless other then topping off the pack over a few hours period of direct sunlight. Our packs are good for maybe 1 mile of actual propulsion so after a little math, it just doesn’t add up.

___On the modding of your CVT, it almost sounds like you might prefer the 5-speed? The efficiency gained by lean burn alone will do far more for fuel economy then a yard full of solar panels charging our smallish packs.

___In terms of high external temperatures, keep the windows cracked a small amount or ventilate before taking off. The solar panel fan mod was a neat idea but in Boston, just as in Chicago, it isn’t that hot on most days? In terms of cold, an engine block heater is available for out Insight’s and the cost is < $35.00. Plug it in and you are done considering a thermos to hold coolant at higher temperatures (ala Prius II) or whatever … Mine is still sitting in a box waiting to be installed in another 3 or 4 weeks.

___I don’t know? Fuel efficiency can be extended and maintained using Hypermileage driving techniques and the simple setups far more then anything discussed so why not start there instead? I love reading about the mods many do to our little beauties but after driving my own for almost 30,000 miles now, fuel economy comes from the simple stuff like using the car as it was built with warm air mod(s) and high pressure tires, not the wild ideas and there implementations some here have tried in my short experience. Not that I am not interested but Honda built one hell of an efficient automobile and asking for much more with lots of HW changes is like diving into a pool devoid of water. It is going to be painful and the outcome may not be what you expect.

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:3dcdfrf8][email protected][/email:3dcdfrf8]
 

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DonWatson3558 said:
Ok, so have I really lost it? Need to be committed?
Well if you're off to the loony bin then I should be going too!

I thought about this possibility in terms of the Daihatsu UFE-II a while back, calculating how many miles of daily range could be achieved using today's best solar cells on the roof. The answer was amazing, 53 miles per day with today's commercially available solar cells. 8)

So here are my thoughts on that translated to a modified Insight....

1) The Insight is 1695mm wide by 3945mm long. From above, that's 6.7metres squared of footprint. However, only about 70% of that will be available for solar panelling, so call it 4.7 metres squared.

2) In much of the US, the average incident solar energy is about 5 kilowatt hours per metre squared per day, (averaged over the whole year - in summer a lot more, in winter a lot less). That means the cells on the modified Insight could be exposed to 4.7 x 5 = 23.5 kWh per day.

3) However, no solar cell can convert 100% of that to electricity. The best you can buy today are SunPower A-300, independently verified at 20.4% efficient. So, the modified Insight would only absorb 23.5 x 0.204 = 4.8 kWh per day.

4) The amount of power provided by the cells on the whole roof is tiny! You're looking at a maximum power of just 960 watts, or just a fraction over 1 horsepower! There is no way this amount of power can propel the car directly.

5) Therefore, the 4.8kWh has to be stored over the whole day in a storage battery, and the Insight has to be modified to have an EV mode (say 100 miles worth of lithium-ion storage).

6) Assuming an efficient EV drivetrain, at 7 miles per kWhr, you'd be looking at an all solar EV range of 7 x 4.8 = 34 miles per day, or about 12,000 miles per year.

Of course when the sun doesn't shine or you park it in the shade, you'd have to use the ICE. But as an eco-friendly alternative to gas, you can't go far wrong with pure solar! 8)

[Edited to update weblinks]
 

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xcel said:
___As Insightful Trekker has already mentioned, the energy output of a roof full of solar cells is so small as to be almost meaningless other then topping off the pack over a few hours period of direct sunlight. Our packs are good for maybe 1 mile of actual propulsion so after a little math, it just doesn’t add up.
That's good news! Although I had never considered trying to directly propel the car any distance at all with solar, perhaps it's something to think about. I think I'll keep my focus limited to just topping off the batteries. Topping off the batteries once a day would be a great improvement compared to the ONE time it has ever been topped off since have I owned the car. Topped off batteries means good improvement in downhill MPGS on a CVT.

xcel said:
On the modding of your CVT, it almost sounds like you might prefer the 5-speed? The efficiency gained by lean burn alone will do far more for fuel economy then a yard full of solar panels charging our smallish packs.
Could be true. I have had a stick since college. I'm now 46, and the Insight is my first automatic. However, I didn't buy the Insight because of fuel economy alone. I bought it because of a life-long passive interest in the technology. Also, I feel in my own small way, it's my contribution to the war effort. While I am not unhappy with the CVT, I would not be any "happier" with the 5 speed. In fact, if I owned the 5 speed, I would be exploring ways to improve it's economy from XXXMPG to XXX+YMPG -- likely via solar. I think much of the discussion on this message board explores Insight mods for the same reason -- not because something is bad, but an interest in how to improve/enhance the technology and make it beter. In this case, I don't want to modify the technology -- only augment it.

xcel said:
___In terms of high external temperatures, keep the windows cracked a small amount or ventilate before taking off. ..... In terms of cold, an engine block heater is available for out Insight’s and the cost is < $35.00. Plug it in and you are done considering a thermos to hold coolant at higher temperatures.
True. Cracking the windows helps. I just bought a Covercraft sun shield, and also installed the Honda engine block heater last weekend. But I'm not done condidering the thermos. I do fear issues with it ... difficult to install, impact on warranty, etc. In the end, it may never get done, but from a technology improvement viewpoint, I want to consider it to see where it takes me. One idea usually leads to a better idea.

xcel said:
Honda built one hell of an efficient automobile and asking for much more with lots of HW changes is like diving into a pool devoid of water. It is going to be painful and the outcome may not be what you expect.
Very true ... as a matter of fact, almost most all of the mods I have heard fit this description. Second guessing how the internal software works, and modifying the engine and/or fooling electrical systems sounds like driving through quicksand to me. When and IF I install a solar system, I just want to help top off the batteries and do some other projects that don't involve monkeying with the Insights internals!
 

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clett said:
Well if you're off to the loony bin then I should be going too!
Maybe we could get a discount if we placed a group reservation!

The data you provided is fascinating!

clett said:
That means the cells on the modified Insight could be exposed to 4.7 x 5 = 23.5 kWh per day ....However, no solar cell can convert 100% of that to electricity. The best you can buy today are .... independently verified at 20.4% efficient. So, the modified Insight would only absorb 23.5 x 0.204 = 4.8 kWh per day.

.... The amount of power provided by the cells on the whole roof is tiny! You're looking at a maximum power of just 960 watts, or just a fraction over 1 horsepower! There is no way this amount of power can propel the car directly.

... Therefore, the 4.8kWh has to be stored over the whole day in a storage battery, and the Insight has to be modified to have an EV mode (say 100 miles worth of lithium-ion storage).

.... Assuming an efficient EV drivetrain, at 7 miles per kWhr, you'd be looking at an all solar EV range of 7 x 4.8 = 34 miles per day, or about 12,000 miles per year.
As you indicated, It looks like a system could be devised to actually store away energy and use it to propel the car. If a 3rd battery were to be solar charged for a day, you could spend 4.8kWhr of energy to move you about 34 miles down the road in about 34 minutes. Cool.

That might be something I could look at after my 7 year, 100,000 mile warranty expires! (I'll put your post away for safe keeping, and look at it again in 2011! Ha!)

If enough energy "could" be generated to propel an Insight 34 miles per day, then could not that same amount of solar eneragy go a very long way towards keeping the NIMH batteries topped off (with power to spare)?

Moreover, assuming only the roof had panels, couldn't 960 watts per day more than accomplish the same task?

The SOC displays a 20-80% battery state. I have only ever dropped to 3 lines below max. 95% of the time, it is only 2 lines below. 0% of the time it is full (representing the crux of the problem I am trying to solve).

Assunming the SOC shows a battery charge state of 60% of its capacity (range of 20% to 80%), if the NIMH's hold X amount of stored energy when "full" (80%), and the SOC shows 2 bars below max out of Y number of bars total, how much power would it take to charge (E kWhr) such that the SOC shows full (80% capacity), and in what amount of time (T)? (Assuming some constant for watts produced by available panel array)?

I guess my next job is to seek an answer to the above questions. I realize the SOC probably does its best to show a charge state that is more polynomial rather than linear, but maybe a ballpark estimate could still be made.

It would be intersting to know these numbers. At first glance, looks to me like a solar roof panel could perform the top-off more than once per day.
 

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Wow, the longest post record has been shattered! :wink:

DonWatson3558 said:
...I often wonder if a contributing factor as to why CVT's get poorer MPG is due to the restrictions on how and when assist is applied. I know everybody attributes the primary difference to the lack of lean-burn, but I am not so sure. Perhaps restricted assist is 1/2 the reason, and lean-burn is the other half. ...
I think you are right about that.

Let me back up a bit. Your sole goal is to avoid charging while coasting, right?

Why would you not consider a "I didn't let off the gas pedal" mod? I think this would have much less chance of causing damage to the rest of the system than adding an outside charging source, and would solve your problem in the most direct fashion. I don't know, however, if such a thing is actually possible, but look how easy the forced regeneration switch is.

What about (gasp) cruise control?

Don't get me wrong, I am all for harnessing wasted energy (that's one of the main reasons I drive an Insight), I'm just askin'

If you are set on solar charging, more power to you (ha ha). I can't help you much there, but would be highly interested in the progress.
 

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DonWatson3558 said:
Assunming the SOC shows a battery charge state of 60% of its capacity (range of 20% to 80%), if the NIMH's hold X amount of stored energy when "full" (80%), and the SOC shows 2 bars below max out of Y number of bars total, how much power would it take to charge (E kWhr) such that the SOC shows full (80% capacity), and in what amount of time (T)? (Assuming some constant for watts produced by available panel array)?
The Insight battery is made up of 120 NiMH cells, each rated at 1.2V. Total voltage is 144V, and at 6.5Ah that gives a total capacity of 936 Wh. However, if the software ensures it only cycles between 20% and 80% SOC, 60% of capacity is available, which is 562 Wh actually available.

The 960 watts I mentioned was peak power, ie noon-day sunshine, when it's usually about 1kW/m2 incidental. At this time it would take (562 / 960) = 0.58 hours or about 35 minutes to top up from zero bars to full bars. A smaller install, say only 1m2 on the roof, would take 2hrs 45mins.

However I still think it would only be worth your while doing if you had a big enough battery installed to make the most of it. Maybe a LiIon pack in the boot driving the back wheels to "assist" the fronts when the accelerator is depressed? :wink:
 

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"With my CVT, charging on decererations during highway driving is not free. It costs! I have to apply the gas pedal (pulling power from available energy sources) to get down the descent!"

I don't think you quite understand the way the Insight works. When you're going down a hill and it's showing charging, that is the equivalent of the braking effect you'd get from a "normal" car at zero throttle. The Insight is in fuel cutoff, so using no gas at all.

Now if you press the gas pedal lightly, just enough to turn off the charge bars, you're no longer getting the braking effect, but are still in fuel cutoff and using no gas. Only if you press still harder will you start actually pulling power from the engine.
 

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James: I will support DonWatson on that issue. The "charge-braking" or "coast-charging" is real. Times when my battery will not charge further, or if I choose a gear that results in rpm's being below the charge threshold, allow me to coast much more freely.

At least for the manual transmission, I know about this. I have no experience with the CVT.
 

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"Times when my battery will not charge further... allow me to coast much more freely."

Yes, that's what I'm saying. Charging takes energy, and this energy comes from the momentum of the car (and ultimately from gravity, on a downhill). However, if you press the gas pedal just enough so that the charging stops, you will still be in fuel cutoff mode, and thus burning no gas. So the driver has a choice: foot completely off the gas slows quicker & recharges, light touch coasts further with no charging but no fuel used.

I know you all, being on the east coast, don't have a lot of long steep downhills, so you probably don't get to see it in action as much as I do, but I think the Insight is actually set up fairly reasonably. On a long downhill, mine maintains around 60 mph with my foot off the throttle and charging. When I get near the bottom, it'll generally be fully charged, and then speed will increase to something over 70. I don't know exactly what, as there's a stoplight at the bottom, and a sharp left turn :)
 

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James: Thanks for the post. In fact, my experience matches your description exactly. In my big 1st post (I realize it's too big), I said:

DonWatson3558 said:
(4) I often have to apply pressure to the gas pedal on descents in order to stop it from charging the battery in order to maintain speed DOWNHILL.
With the method you describe, we CVT drivers can overcome the problem. I guess my concerns with it are as follows.

james said:
... going down a hill and it's showing charging, that is the equivalent of the braking effect you'd get from a "normal" car at zero throttle. The Insight is in fuel cutoff, so using no gas at all.
I know -- I expect too much, but I didn't buy a normal car, I bought an Insight. Knowing regular cars with auto trans have a somewhat analogous slowing phenomenon when lifting up from the gas, doesn't give me great comfort. If they had CVT transmissions, then one could say the Insight slows downhill, but normal cars with CVT do not. But, in fact, you are very correct. I just get a little disappointed because I feel the car has very incorrectly assumed that I want to slow down. I feel it's bad a bad error in judgement! (Ha!) It seems like the software engineers at Honda made a design mistake here, but that's just a feeling ... not an accusation.

As you probably read, I experienced full charge on my CVT once. As I experienced traveling down small descents.... not having to constantly monitor the gauges, not having to precisely apply pressure to the pedal (not too much, not to little! Oops, correct, ok ... I got it) was an incredible joy. Far superior to driving any automatic! Also, I sense that it takes me longer to get into fuel-cutoff mode because I have to play with it on every descent. I do get there, but it could have been much earlier. Although I'm pretty good at it, I often goof it up ... enter charge mode, and then have to fight my way out of it while trying to save MPG.

So, for my driving there is a cost ... I think I look at the gauges more than I do the road! Good thing the Insight has them in front of you and not like the Prius!

I have an even bigger cost when my wife drives. Although she is excited to have an ultra economical car, she just doesn't get into hyper economical driving techniques. She also doesn't get into me constantly giving her back-seat-driver (oops, passenger-seat-driver) instructions. I advise a bit, but in all fairness to her, that's the best I can do. She enters charge mode on the highway all the time. Starting at 60MPH, she will begin to go down a descent. It will start charging, the speed will drop to 55, she will press the gas, then harder, assist will kick in, gas mileages goes down toilet, gets to top of next hill at 60MPG, and then starts the process all over again --- all she knows is that she kept the speed between 55 and 60, and figures she's done a great job. If the regen charging had not kicked in, she could start going down a hill at 60, get to the bottom at 65, climb to the top of the next incline at close to 60 -- all with no charging and no assist! THIS HAS GOT TO BE BETTER! Also, she consumes not only more gas, but more electricity using assist to climb than she ever collected by charging downslope. Having a topped-off battery would go a very long way towards eliminating this problem! It's not flat where we live. I wouldn't call them "big", but it's lots of ups and downs ... one after another.

I suppose most members of this forum normally use hyper economical driving techniques without thinking about it. However, most people in general would just drive it. Perhaps this is a flaw in hybrid verhicle technology today.

Having a fully charged NIMH battery, people who "just drive it" would benefit greatly. I feel like I would benefit by not having to work as hard to achieve higher mileage combined with actual fuel savings.

Holicow's observation is correct as well, although I am not sure it conflicts with what you said. It seems we have all been tantalized by non-charging coasting down descents and hills, and could become easily addicted!

As I have stated previously, most people attribute better MPG with 5 speeds to lean burn. While that is a factor, I sense 5 speeds don't suffer from this problem as badly. I would suggest the difference in MPG is more complicated than just lean burn. I don't say this emphatically, and won't do so until I have the opportunity to evaluate a 5 speed.

I often think about what makes hybrid vehicles beneficial. I am pondering the thought that the only purpose for a hybrid is to compensate for poor driving habits. Maybe if people (on average) didn't drive so poorly (non-economically), we would have neither the need for charging nor assist. All a hybrid can do is try to compensate -- sometimes it's successful, and sometimes (as in this case) it can make things worse. No matter how you slice it up, 1 + 1 does not equal 3.

In summary, I don't believe there is any way to fix this problem without an augmentive energy source. I suppose the problem is intrinsic to a balance which must occur between fuel and electricity generated by the same fuel.
 

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DonWatson3558 said:
clett said:
Well if you're off to the loony bin then I should be going too!
Maybe we could get a discount if we placed a group reservation!
To be honest I've been thinking about the possibility of this for ages as the numbers just stack up so convincingly, but every time I've suggested it I've been roundly branded as a mad-man!

So in my defence, I'd like to point out this fantastic website that I've only just discovered - it's absolutely amazing!

This guy has taken an ordinary van, converted it to electric drive and added 20kWh of Thundersky lithium ion batteries to it (100 mile range).

But THEN he's added 200W of solar panels to the roof AND a 400W wind turbine! Given the right weather, that could stack up to over 11kWh per day, or a 55 mile range with no need to plug in to recharge! It can conceivably be driven with no oil or grid connection required whatsoever, ie an entirely renewable energy powered vehicle!

OK, it's a home made DIY version for now lacking in several areas, but if a guy can build something like this for just £9,000 in his shed, imagine what the potential range and minimal environmental impact would be if he had built it around an Insight!

Enjoy!

http://www.solarvan.co.uk/index.htm

http://www.carkeys.co.uk/features/everything_else/925.asp

8) 8)
 

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Great van and great idea (wish the Insight was as square as this van for the solar panel position), thanks for the link.

I guess I'll have to read this entire tread now. I was too lazy to read the 'long' messages. But I missed the infos.
 

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OK, I read the entire tread (ouff)

Solar charging:
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Personnaly, I think that solar charging can be a good idea. On the Insight, there is not much surface and I think that the small charging that can be added would about compensate for the IMA battery degradation. A direct connection to the battery (with top voltage and drain control)
When there is a recal, it is because the SOC is lower than expected through the metering. The solar charge would bring it closer to the expected SOC. I am sure that the solar charging is not enough to surpass the deterioration in charge level. As the Insight's programs does not seem to take deterioration into acount.

More assist:
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I have often experienced (I have a manual) that when the gas pedal if fix and go at a sudden small incline, the MPG display is steady at the same MPG but the assist goes into play. I expect the system to read the gas pedal has not changed but the engine load has raized, therefore it compensates with assist, not more gas from the ICE.

I beleive that if there was a way to make the system see a sudden engine load while the gas pedal has not moved, it would use more assit.
Maybe use an interface between the gas pedal position sensor and the car's computer. It could freeze the pedal position while drive and you could press the pedal more. The TPS would be hocked up to an transistor which would then give the variable/controled result to the car's computer.
Or an interface with the vehicuke speed sensor VSS to show a drop in speed could create an assist situation.

More charge:
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I do not know how but the Insight's computer will charge when the engine is not under a specific load. We need to make it beleive that the is just enough load to charge.

My 2 cents.
 
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