use of solar panel at spoiler on roof?

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garygid said:
Just do not park in the shade.


I can imagine a whole new type of road-rage here, with angry solar car owners trying to keep out of the shade of high sided vehicles as they are driving along, or writing rude notes on the windshields of vans who dare park next to them and leave them in the shade! :lol:
 
Given that Toyota has said the optional panel on the 2010 roof does not generate enough electricity to be of value charging the traction battery, the small one on the Leaf spoiler would be pretty worthless.

The panel on the Prius only covers part of the roof as it ONLY comes with the 'moon roof'. One would hope that in the back labs somewhere, the engineers ARE thinking about ways to generate usable amounts of electricity from the roof and hood as is done on the EV distance race cars.
 
I've been attempting to measure whether the solar panels are charging the battery or not. I have full sun on them around noon and am monitoring the 12-volt battery at around 12.62 volts on my digital voltmeter. Covering the panels doesn't change the voltage at all, even after waiting several minutes. Uncovering the panels again likewise does nothing. There should be at least a small change in voltage if the panel is charging the battery.

I also measured current directly. I never saw any reverse flow of current into the battery. In its quiescent state, the car seems to draw on the order of 20 milliamps from the 12-volt, probably to run the clock, keep the nav system memory, probe for the intellikey, etc. It's a very low draw, and it would take months to deplete the battery. Again, covering and uncovering the solar panel made no difference that I could detect even at this low current.

Opening a door and running the interior lights draws about 4 amps(!), then closing it again, the system continues to draw 1.5 amps for a few minutes, dropping to a lower level later on. I suspect that waking the system leaves it in a more alert state, running some computer or probing continuously for the key; who knows? My thought was that if the battery were fully charged to the point where the panel wasn't putting current in, then discharging the battery a bit for a few minutes should make a difference. It didn't seem to.

The upshot is that I can find no evidence that the solar panel is even connected to the 12-volt system, leaving a big mystery as to its purpose, beyond the obvious marketing gimmick.

-Greg

P.S. I read somewhere -- in the manual? -- that the Leaf wakes itself up every week or two to recharge the 12-volt battery from the traction battery using its DC-DC converter, just to make sure it doesn't go dead. The solar panel is really not needed, even for keeping a charge on the lead-acid battery in other words.
 
gregoryjward said:
I've been attempting to measure whether the solar panels are charging the battery or not. I have full sun on them around noon and am monitoring the 12-volt battery at around 12.62 volts on my digital voltmeter. Covering the panels doesn't change the voltage at all, even after waiting several minutes. Uncovering the panels again likewise does nothing. There should be at least a small change in voltage if the panel is charging the battery.
In the service manual it looks like the solar panel is more-or-less directly wired to the 12v battery. As a result, you're probably measuring "backflow" from the actual 12v battery. The proper testing procedure, according to the service manual, is to disconnect the 12v battery negative terminal, then measure the voltage across the positive and negative terminals. That will effectively remove the battery from the equation...
 
Forgive me for a dumb question, but I was wondering if you leave your lights with fogs in the sun for 8 hours would the battery die or solar panel would be putting enough charge to keep it alive?
 
I have directly measured the output of the solar panel. It is about 5 watts in full, mid-day, direct sun. Hardly enough to be of any real use. If you haven't changed out the four incandescent bulbs for LEDS, with the headlights on you have a draw of about 42 watts.
 
gregoryjward said:
I've been attempting to measure whether the solar panels are charging the battery or not. [...] I also measured current directly. I never saw any reverse flow of current into the battery.
I did the same test, saw the same behavior, and I did see the current go to zero, then negative. The most current I saw going into the battery was around 35 mA. I figure in bright sun, it's almost enough to offset the draw when the system's asleep, on average. Not much at all.
 
It's a gimmick, I would rather have seen it gone and have the money toward a better stereo, a few more tablespoons of paint, extra spray on carpet. etc. It is clear a bunch of marketing boobs that it would be cool :lol:
 
GeekEV said:
gregoryjward said:
I've been attempting to measure whether the solar panels are charging the battery or not. I have full sun on them around noon and am monitoring the 12-volt battery at around 12.62 volts on my digital voltmeter. Covering the panels doesn't change the voltage at all, even after waiting several minutes. Uncovering the panels again likewise does nothing. There should be at least a small change in voltage if the panel is charging the battery.
In the service manual it looks like the solar panel is more-or-less directly wired to the 12v battery. As a result, you're probably measuring "backflow" from the actual 12v battery. The proper testing procedure, according to the service manual, is to disconnect the 12v battery negative terminal, then measure the voltage across the positive and negative terminals. That will effectively remove the battery from the equation...

I replied to this once, but my post got lost(?)

Thanks GeekEV for the tip -- I tried it and indeed the solar panel provides voltage to the system with the battery disconnected. Covering the panel causes the voltage to drop from 12 (or so) down to 1 or 2 volts, proving that the panel *is* doing something.

My faith is restored that it isn't a completely empty marketing ploy, at least.

-Greg
 
In theory if you modified your "power plug" jack to be "always on" instead of "ignition on", the solar panel could provide enough continuous juice to charge your cell phone all day. But, then again, so could the 12v battery by itself. :D
 
gregoryjward said:
GeekEV said:
gregoryjward said:
I've been attempting to measure whether the solar panels are charging the battery or not. I have full sun on them around noon and am monitoring the 12-volt battery at around 12.62 volts on my digital voltmeter. Covering the panels doesn't change the voltage at all, even after waiting several minutes. Uncovering the panels again likewise does nothing. There should be at least a small change in voltage if the panel is charging the battery.
In the service manual it looks like the solar panel is more-or-less directly wired to the 12v battery. As a result, you're probably measuring "backflow" from the actual 12v battery. The proper testing procedure, according to the service manual, is to disconnect the 12v battery negative terminal, then measure the voltage across the positive and negative terminals. That will effectively remove the battery from the equation...

I replied to this once, but my post got lost(?)

Thanks GeekEV for the tip -- I tried it and indeed the solar panel provides voltage to the system with the battery disconnected. Covering the panel causes the voltage to drop from 12 (or so) down to 1 or 2 volts, proving that the panel *is* doing something.

My faith is restored that it isn't a completely empty marketing ploy, at least.

-Greg

After having so many people ask me about the solar panel with excitement, I do think it's worth having as an arrow pointing people in a good direction and it may even help inspire some to take the extra step to installing a substantial solar array on their house. we can hope!
 
I have been using a 1.5 Watt solar panel to keep my ICE car's and ICE motorcycles' batteries topped up when I am not driving/riding the vehicles. Although it says 1.5 Watt, it only gives out a few milliamps of output current. The solar panel trickle charges the batteries very well. I have been using them since five years and the batteries are still working. I am very confident that Nissan Leaf's spoiler solar panel is even better than my cheap solar panel, so it definitely helps keep the 12V battery charged up. These solar panels work even in overcast, cloudy skies and even under fluorescent lighting in garages. Although the current is tiny under such situations, it still manages to prevent the 12V battery losing charge. If it is unable to increase charge, it will at least maintain the charge. Most batteries lose charge with time even without any power draw. Here's what I have been using, these are available with different name brands from different retailers but overall they are the same thing from China:
41DRvdCyLjL._SX300_.jpg

http://www.harborfreight.com/15-watt-solar-battery-charger-68692.html
 
Has anyone tried to access the panel wire directly? I'd love to charge a small lithium-ion battery, and have that battery power my dashcam recorder while the car is turned off, instead of using one of those add-ons which can cut power to the cam when the 12V battery drops below a certain voltage.
 
EVerlasting said:
I have been using a 1.5 Watt solar panel to keep my ICE cars and ICE motorcycle batteries topped up when I am not driving/riding the vehicles. Although it says 1.5 Watt, it only gives out a few milliamps of output current. The solar panel trickle charges the batteries very well. I have been using them since five years and the batteries are still working. I am very confident that Nissan Leaf's spoiler solar panel is even better than my cheap solar panel, so it definitely helps keep the 12V battery charged up. These solar panels work even in overcast, cloudy skies and even under fluorescent lighting in garages. Although the current is tiny under such situations, it still manages to prevent the 12V battery losing charge. If it is unable to increase charge, it will at least maintain the charge. Most batteries lose charge with time even without any power draw. Here's what I have been using, these are available with different name brands from different retailers but overall they are the same thing from China:
41DRvdCyLjL._SX300_.jpg

http://www.harborfreight.com/15-watt-solar-battery-charger-68692.html
I used one of these in my car for quite a while. I had a cheaper, run of the mill battery, and it lasted a good 7 years even with me not plugging it in all that often. It was my understanding that the battery I had would normally last about 4 years so not bad at all!
 
Old thread I know. But I thought Id let you guys know I just found an oem panel on ebay for $179.99. I thought it seemed pretty reasonable considering its an OEM part.

http://www.ebay.com/itm/296E0-3NA0A-Nissan-Leaf-Solar-Panel-Cell-NEW-OEM-296E03NA0A-/111372087482?pt=Electric_Vehicle_Parts&hash=item19ee4b30ba&vxp=mtr&autorefresh=true" onclick="window.open(this.href);return false;
 
Testing of the Nissan's Solar panel showed that it put out a measly 13V or so. Enough to maintain the battery in direct sunlight, but not charge it. It may slow the drain of the battery, but it's widely considered useless.

You're probably much better off replacing the Nissan made panel with a quality auto solar maintainer. You could wire it into the same harness and get an actual benefit.
 
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