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The following is a modification I had performed last year for the purpose of keeping my accessories battery topped off. Given the accessories power drain in my car and the colder climate this mod has proven very valuable to me in the past in more than one ocasion. As a result and under request from several folks at GreenHybrid and CleanMPG I decided to post it for the CleanMPG community as well in hopes that it may also be beneficial to other HCH-2 owners.

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My apologies for the (low light)pics ... I took these in overcast day again. It looks as if I only get these requests only when the weather is acting up. :(

First of all, I should emphasize the not so obvious first:
This solar panel installation does NOT tap into the traction NiMH battery! Instead, it is meant to keep the rather small (in size and capacity) 12V battery topped off.

What does this mean? It means that this solar panel mod does not have any direct impact on fuel economy worth calculating. If you wish to go through the exercise then please do so at your convenience... and please do share the methodology ;).
This is not to say that the mod does not contribute to higher FE. However, in the absense of the necessary calculations, any assertions of this kind are only supported by inferencial analysis and/or subjective observations.

Now, for the more obvious: My personal HCH-2 actually has two solar panels. One "permanently" mounted at the rear of the car (as shown in the following pic) and another that I have stowed inside which I use on the front dash when I feel like it. http://greenhybrid.com/discuss/images/smilies/emotikons/wink.gif

http://www.cleanmpg.com/photos/data/522/HCH_RearSolarPanel.jpg

Now for the above, I drilled a hole into the plastic trim and then ran the wiring to the trunk. From the trunk the single wire (+ve) was run past the rear seat into the cabin and then under the carpeting on its way to the fuse box.

http://www.cleanmpg.com/photos/data/522/HCH_RearSolarPanelInside.jpg
Here's another view, this time from the rear right passenger seat. The solar panel is kept in place with double-sided adhesive (10mm) insulating foam and velcro... so that it is not only noiseless and easy to remove, but also slightly tilted to the back.


The following pic (not very clear - I'll take another one at a later time) is the fuse panel. I've connected the RED (+ve) feed from the solar panel(s) to this particular fuse position. If you notice, it is an empty fuse position but any other vacant fuse socket will do. Use a multimeter to make sure you plug it in to the correct fuse contact. In this case, the lower contact is the live rail.
http://www.cleanmpg.com/photos/data/522/HCH_RearSolarPanelFusePanel.jpg

The second wire from the solar panel can be connected to any good ground point in the car. For the rear mounted panel, I found a good ground in the trunk which enabled me to run the single wire (+ve) to the fuse panel.


The following pic shows the dangling connector for the second solar panel, which I mount on the front dash whenever I deem appropriate. :cool:

http://www.cleanmpg.com/photos/data/522/HCH_RearSolarPanelFrontConnector.jpg


The following pic is a sample of the actual solar panel. I bought quite a few of these at Canadian Tire when they were on sale last year. Pretty good deal I must say.
http://www.cleanmpg.com/photos/data/522/HCH_SolarPanel.jpg

This panel is rated for a max current of 125mA and 17 volts when placed perpendicularly to the direct sunlight. In an overcast day it can produce a current flow of at most 40mA with the sustained load of the 12V battery plus the other accessories.


Anyhow, that is all there is for the rather simple install.

What's the point? Does it work?
It works for me because I have a slightly higher than normal power drain on my system on the account several permanently active systems in the car.
If you are one of those folks who also drive no more than 10 mile trips and never have a properly charged 12volt system (especially in the cold winter months at -40F) then this MAY be for you.
It should not be too hard to see that it is in my interest to supplement the power drain that would otherwise come from the IMA battery. In my case the 12V battery (and I suspect the same for some other folks) will ALWAYS take a charge... I categorically observe the phenomenon every single day. And if you have current flow, then it is taking a charge (or at the very least supplementing a existing loss).

How you use your IMA SoC is still up to you. I prefer to use less of it to keep my 12V system charged.


Cheers;

MSantos

I use a very similar solar trickle charger, but I have it suction cupped to the bottom of my windshield, and tapped a very small hole through my firewall to hook it directly to my 12V battery.

It recharges the 12V battery at the rate of 1/100 volt every 120 seconds or so, in strong sunlight. So, for every hour it's in the sun it charges the battery about 0.3V.

On a harsh day my battery is at 12.3V when I park it. With decent sunlight the battery will be back to fully charged at 12.8V in about 1.5 hours. On a dark. cold and overcast day it can take a lot longer than that, but it's always charging, even if it's just a tiny trickle.

Nice use of a small solar panel.

I picked up some cute solar panels at the MIT swap meet last month.

They make it easy to build any voltage or current solar panel with what ever form factor you want. I made a 256V panel with 56 of the cells, with the idea of topping off the IMA battery while parked in the sun. The 85ma max current should not damage the pack if it reaches overcharge conditions. the guy is selling the cells on e-bay.
Info about the cells and some photos of solar stuff that I have built with them is at:
http://www.99mpg.com/mikestips/
Yes the panel is potentially lethal, just as a series string of 9V batteries can be if the voltage gets up there, so don't play with this unless you know what you are doing.
Just wanted to share the solar cell find with the group.

;)

In light of the unintentional severe overcharge of the Prius subpacks and their continued operation, I am going to try the 250V solar panel charger for my Insight IMA pack.
At 85MA, it is not going to hurt anything. The panel fits right in the rear hatch window.
Will advise as to how it works.

Yes, please let us know.

85 mA is indeed a small figure so I agree it should be pretty safe. Sorry, I did not look at the details of your project yet (will do it later) but I am curious of how you are interfacing the supplemental Prius batteries to the existing OEM pack?

In my spare time (I have less and less now) I've been producing a few simulation circuits... all in hopes that when my warranty runs out I can bank some quality bench time. Some of the things I'm wishing for is a means of extending the battery capacity with an additional parallel bank paired with a cooperative charge controller.

In the meantime, I do enjoy reading about your exploits in this solar charging area. Please keep'em comin' ;)

Cheers;

MSantos

I used supplemental Prius batteries for my first test of concept, now I use 48V of lead acid.
I still plan on building a prius subpack based version some day.

best way get the whole picture is to read this blog:
http://www.99mpg.com/Projectcars/TheBestHybridmix/
for the whole story.
The short version:
http://www.99mpg.com/projectcars/mikesinsight/

Short solar panel attachment to Insight CVT on a stand yesterday showed .8V rise in pack voltage in ~10 minutes. Also added a series diode and fuse just in case.
Boost controller schematic:
http://www.99mpg.com/Data/resources/downloads/relateddocuments/boostschematic.pdf
;)

Sorry to dig up this old topic but I really like this idea!

Looks like a nice setup. I would love it because half of my commute is at night and I FAS about 40% of my drive home, which has to be a strain on the 12V. I noticed that it comes with a cigarette lighter plug as well. This probably won't work with a HCH, right? I think I read something about the cigarette lighter plug having its own circuitry protection system.

HemiSync:

You are quite right. Most of the low wattage retail panels come with "cigarette/power" socket plug which is useless in many of today's cars (ours included).

Usually, there's a bit of work associated with a proper installation and due to popular demand, I expect to be providing an update to my earlier article that includes really detailed steps.
Also, the main reason why I'm doing this is because I've committed to installing a new set of panels on 4 other HCH-IIs over the next two weekends.

These new panels are of larger capacity (2.4 Watts) and I bought a full box of them at Walmart for $10 each !!!! yep, check your Walmart store ! These beauties were on sale in my area !



Cheers;

MSantos

I just saw some on ebay motors that actually plug into the OBD II port. I didn't even know this was possible. But appears VW made some for their cars and were used in dealer transportation to maintain the batteries. I don't feel comfortable plugging something into that port that delivers a charge, but thought it was worth mentioning.

I look forward to your detailed steps and hopefully you make it easily detachable for the peeps that still have warranties. ;) I will check my Wally world tonight after work, were they in automotive department? Thanks for the heads up!

FWIW.
The Insights had a similar 12V discharge issue when doing FAS. We found that a single dc/dc enable line controls if it is off or keeping the 12V system actively regulated from the HV batteries.
I expect that the civic HCH has a similar line. While not a cool as having a solar charger,a switch to keep the dc/dc enabled will allow fas for long periods at night without concern for the 12 system dropping out.

...
I expect that the civic HCH has a similar line. While not a cool as having a solar charger,a switch to keep the dc/dc enabled will allow fas for long periods at night without concern for the 12 system dropping out.

Mike, that is a great idea.

But I believe things are not so easy in the HCH-II since almost all critical control inputs travel over the CAN bus.
Nevertheless, it is certainly worth a look. I'll come back with some feedback on this issue later today. ;)

Cheers;

MSantos

I suspect that many of the low level control lines are still handled with a simple logic state change?
The Insight dc/dc has a PWM charge control, and the single enable line.
Anxious to see what you find.
;)

...I will check my Wally world tonight after work, were they in automotive department? Thanks for the heads up!

Yes, automotive department !

Here are some shots of what the packaging/product looks like:
http://www.cleanmpg.com/photos/data/522/2_4WSolarPanelPkg1.jpg
http://www.cleanmpg.com/photos/data/522/2_4WSolarPanelPkg2.jpg

Like I said, I bought a whole bunch of these (still in the box) for $10 each. Quite a deal for a 2.4Watt unit.

Cheers;

MSantos

I suspect that many of the low level control lines are still handled with a simple logic state change?
The Insight dc/dc has a PWM charge control, and the single enable line.
Anxious to see what you find.
;)


OK, I'm going to run some tests in a few moments. As far as I can see, the DC-DC converter on the HCH-2 has basically two "means of being controlled".

1- The four pin connector has 2 lines that come from the BCM and pin A19 is the comm line to the DC-DC. Pin A18 also comes from the BCM but I believe it is the counterpart to A19. I don't yet know which is the send and which is the receive. I'll find out later I guess.
2- The number 3 fuse (10A under dash) controls the operation of the DC-DC.

Beyond the above, it looks like there's little else I may want to play with as the other connections are the "just power" points.

Cheers;

MSantos

FWIW.
The Insights had a similar 12V discharge issue when doing FAS. We found that a single dc/dc enable line controls if it is off or keeping the 12V system actively regulated from the HV batteries.
I expect that the civic HCH has a similar line. While not a cool as having a solar charger,a switch to keep the dc/dc enabled will allow fas for long periods at night without concern for the 12 system dropping out.

Mike, that is a great idea.

But I believe things are not so easy in the HCH-II since almost all critical control inputs travel over the CAN bus.
Nevertheless, it is certainly worth a look. I'll come back with some feedback on this issue later today. ;)


I hate to admit it but you guys lost me on this one, just call me all-thumbs when it comes to fixing just about anything on a vehicle, especially my HCH.

Yes, automotive department !
Like I said, I bought a whole bunch of these (still in the box) for $10 each. Quite a deal for a 2.4Watt unit.


Well checked with the three stores around me and they haven't seen them yet. Guess I will have to wait and see. Going to call my folks down in Florida and see if on their next trip to the Wally's & Sam's Club they can check there also. With all the sun & boats down there you think it would be a big seller there. Funny that the Canada sees them first. :cool:

OK, I ran the tests a few moments ago based on my early interpretation of the physical connection criteria. This is what I found:

Option 1:
When inspecting (and trying to profile) the signals on the A19 and A18 pins that come from the BCM I got a series of DTC codes:
U1220 and U1221 - Essentially saying that the BCM and DC-DC lost the communication with each other. This happened each time I "fiddled" with each line. I now know which is the send and which is the receive. To do this, I used a "high impedance" low noise digital probe (100MHz) to peek into the "signal stream" and what I saw almost looked that a clocked/serial bit sequence. Let's just say this warrants further investigation.

Option 2:
Disabling the DC-DC fuse creates a sequence of codes as well where one of them is the U1221 code I got before which says the BCM lost the connection with the DC-DC; of course, it makes perfect sense knowing what I know now. However... putting the fuse back did not solve the IMA failure codes I got subsequently... So I powered everything down for 5 minutes (via the 12V and the IPU's master switch) and that cleared everything.

I am not giving up as I still would like to "peek"into the A19 and A18 lines more carefully, but I fear that disabling(or inhibiting) the inverter is not as easy as watching a threshold state value. :(

Cheers;

MSantos

Yes, automotive department !

Here are some shots of what the packaging/product looks like:
Like I said, I bought a whole bunch of these (still in the box) for $10 each. Quite a deal for a 2.4Watt unit.

Is that 800 number on the package 800 482-4711?

I had my parents in Florida check their stores and still no luck. Thought I might call them and see if they will sell direct or can tell me where their products can be purchased this side of the border.

I believe you got the toll free number right. I'll check it later when I get home since the glare makes it hard to tell for sure.

But also, now that I look at it more carefully... I don't know if you are going to find these parts south of the border either. I hope I am wrong on this one.

If you look on the far bottom right it says: "Imported by Walmart Canada..." :(

Cheers;

MSantos

I believe you got the toll free number right. I'll check it later when I get home since the glare makes it hard to tell for sure.

But also, now that I look at it more carefully... I don't know if you are going to find these parts south of the border either. I hope I am wrong on this one.

If you look on the far bottom right it says: "Imported by Walmart Canada..." :(


Okay, how much you gonna charge all us Yanks for a couple, plus shipping. I can paypal it to you if you have an account. :D LOL

I called that number and the answering machine says SOL Support, leave a message in English & French.

Okay, how much you gonna charge all us Yanks for a couple, plus shipping. I can paypal it to you if you have an account. :D LOL

Yes, I have a Paypal account but I use it only to pay with mostly mainly because recovering the funds from Paypal is awkward. However, I guess I could "ship" them to you at cost and all you would have to worry about is the import tariffs (if any). At the moment all the panels I bought are already spoken for but I can go back to Walmart a pick one or two more depending of how many you want.
Shipping maybe a little expensive (perhaps as much as the cost of the panels ?) and we should include insurance as they are somewhat fragile for mainstream shipping...

The other option is for me to hand them over to you @ Hybridfest ???

Let me know what's best for you.

Cheers;

MSantos

Yes, I have a Paypal account but I use it only to pay with mostly mainly because recovering the funds from Paypal is awkward. However, I guess I could "ship" them to you at cost and all you would have to worry about is the import tariffs (if any). At the moment all the panels I bought are already spoken for but I can go back to Walmart a pick one or two more depending of how many you want.
Shipping maybe a little expensive (perhaps as much as the cost of the panels ?) and we should include insurance as they are somewhat fragile for mainstream shipping...

The other option is for me to hand them over to you @ Hybridfest ???

Let me know what's best for you.

Cheers;

MSantos

I just got a call from Sunforce Products and they gave me several places to purchase them but they are all the 1.8w or 5w version. She didn't seem to know they had a 2.4w version, probably made exclusively for Walmart Canada. But all the places I just check that she gave me wanted $30 for the 1.8w version like we normally see, plus shipping.

Some of those places are Northern Tool, Tractor Supply, Camping World, Pep Boys, & Checker Auto. All of them only have a 1.8w version for $30. She had no information on Walmart, either US or Canada. Strange!

Not sure if I am making it to HF2008 or not. As for Paypal, I was really just kidding, but if you use it on a regular basis, you don't have to claim the funds you just use them on your next purchase, at least thats what I do. I hadn't even considered the tariffs, any idea how much much that would be with shipping, insurance and whatever packaging would be involved? If we did it this way I probably would want two, especially now that I can't find the 2.4w available anywhere else.

Sorry about that.

Yes, I did see their 5W and 1.8W products at the store and the 5W could cut it for most vehicles but definitely not for the HCH as it battery would likely require a charge controller.


MSantos

Cheapest I have found for the 1.8w is at Target (http://www.target.com/Vehicle-Battery-1-8-Watt-Solar-Charger/dp/B0006JO0KG/sr=1-5/qid=1209498529/ref=sr_1_5/602-0296795-6490218?ie=UTF8&index=target&rh=k%3Asolar%20battery&page=1) for $20.

Update: Gee not only are they not the 2.4w but according to their website won't be available for 2-4 weeks. :(

I think most cars have pin 16 on the DLC always-hot. The Prius
fuses it at 7.5A, for example, but it comes right off the battery
lead. Some diagnostic tool manuals warn about this and advise
pulling the tool's dongle when it's not in actual use or it
could drain the car faster.
.
So the idea of stuffing a little charge back up the other way
is perfectly reasonable...
.
_H*

These new panels are of larger capacity (2.4 Watts) and I bought a full box of them at Walmart for $10 each !!!! yep, check your Walmart store ! These beauties were on sale in my area !

:woot: I decided to take the HCH for a test road trip yesterday before driving all the way to Florida and ran her up to Ft. Erie, ON. Dropped by the Walmart there and found all kinds of solar panels, shame our stores don't have any of these. While looking at the many types and sizes the very nice lady asked me if I was looking for something in particular. I told her what I was looking for and she say Oh yea, those came in on clearance and are out on the clearance shelf. Went out there and there were 3 left at that great price of $10 CN. You know I went ahead and grabbed all 3 of them! Still had the original price of $29.99 on them, so should be able to sell off the extra one with no problem. If I have the time I might write up the trip over in the daily grind, there were some fun times at the border. lol

Can't wait to see your detailed instructions for hooking one of these up to the fuse block.

Update:
For anyone foolish enough to read a fool's account of driving 400 miles roundtrip to a Walmart, it is here in the daily grind. (http://www.cleanmpg.com/forums/showthread.php?t=10646)

LOL :D :D

Nice to see you made the most out of your trip. Congratulations on helping that Walmart clear off those solar panels. ;)

Cheers;

MSantos

Just a word on the Eliminator panel available in Canadian Tire we see on the first SMantos pictures. I noticed the very poor quality of the connector when I reinstall this a week ago. On 2 of the 4 male-female-femal-male connectors (we see on MSantos picture), where the cable ends and the connector starts, I was able to see the metal cable and actually, a little twist in the cable would make the + and - touch together. So I re-made all the cabling and discarted the wrong connectors. This to say, or you check the connector upon purchase or do not buy this.

PierreM.

Pierre you do have a point there. That is why my permanently installed panel does not use the OEM connectors at all. Back then and even now, I use a different conductor gauge and I crimp my own connectors. I'll have this illustrated on my updated "how-to".

Cheers;

MSantos

If the build quality is poor, you may be better off building a small panel with the small solar modules that I have been using. Each panel puts out 3.2V @ 85MA. A series string of 5 is 16V @85ma, and a dual 5 panel string or 10 cells is 16V@170MA or 2.7W.
The guy is selling the cases of 170 cells for $150 now, so that brings the cost right in line with these panels, but you can configure the shape to whatever you like. Intergate right into the dash?
http://www.99mpg.com/mikestips/makingsomecustomso/solar_fun.jpg,0

I got one of those panels recently. It's made from the same mould but looks like its lower quality. Anyway, it says in the manual that it mustn't be connected while starting or running the vehicle as this may damage the unit. It would appear that they are afraid of 14v blowing something. Should i be worried about this? It's just hassle unplugging the panel every time i start the car. I'd like to leave it plugged in. I changed the cigarette socket to permanent power, fused....

ollie

On hybrid vehicles I would not worry about any power spikes over the 12V subsystem as they are almost non-existent. Besides the spike voltage on a normal vehicle would have to be much higher than the max rated voltage for these panels which typically rate at 17V. And as usual, it is important to have an inline fuse as it is the combination of the voltage and higher current that can cause the damage. The fuse will not only protect the vehicle but also the panel. I typically use a fuse of 500mA to accomplish this.

Cheers;

MSantos

Thanks for the great writeup you did on the installation of the solar panel (http://www.cleanmpg.com/forums/showthread.php?t=10763).

I think you said to address any questions in this thread but if not let me know and will move my questions over to the other.

For the total novice trying to do this install could you tell / show us a few extra things?


Where is a good place to get the inline fuse?
Can you show us where you placed the inline fuse?
Can you show us pictures of where you attached the ground?
Did you change the gauge of wire going from either the negative or positive side?
What you used to plug the +side into the fuse block?
How would one insure that they are plugging it into the correct side of the fuse block?


These may seem like very amateur questions but a lot of the ones that read your article will be, like me, an amateur. Thanks again for the great writeup. When I get back home will try to do the same with my HCH and will post any pictures that have a noticeable difference between the two generations.

Hi HemiSync;

I've updated the article to include a few more shots from the HCH's I did this afternoon (1 more to go for tomorrow).
Perhaps now it can help answer some of your questions. Let me know if it does not. ;)

Cheers;

MSantos