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Discussion Starter #41
Got to tinker with the solar panel today. First day for a while it's been sunny and I've had custody of the Crosstrek and nothing else going on. Mounting doesn't seem to be a problem - some angled foam on the corners - and no squeaks or rattles. However, I'm disappointed with the output through the tinted sunroof glass. The best I saw was 12.3V and 0.6W and it's a 30W panel, although it's not bright sun today as there's some high cloud and it isn't noon yet so I'm hoping to get some better results later. Washing the car may help, too, LOL!
 

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Discussion Starter #42 (Edited)
Got to tinker with the solar panel today. First day for a while it's been sunny and I've had custody of the Crosstrek and nothing else going on. Mounting doesn't seem to be a problem - some angled foam on the corners - and no squeaks or rattles. However, I'm disappointed with the output through the tinted sunroof glass. The best I saw was 12.3V and 0.6W and it's a 30W panel, although it's not bright sun today as there's some high cloud and it isn't noon yet so I'm hoping to get some better results later. Washing the car may help, too, LOL!
It got less cloudy, though not totally clear and it got up to 2.1W at solar noon. So, hopefully on a good day it will get up to 5W or more. Still pretty crappy for a 30W panel but obviously that rating is the max under ideal conditions, not behind a tinted sunroof on a hazy day. That's why I got the highest output panel I could find that would fit.

Even so, I'm beginning to wonder if it's really going to solve the problem. On a typical day it will be parked in the sun for about 8 hours, so assuming it starts out at about 2W, peaks at 6W around noon, then tails off to nothing in the evening, that's about 2Ah. Is that really going to make a difference to a 62Ah battery? I guess every little helps but the car will have been started at least twice and only driven 5 miles each time. Anyone have any idea how much juice it takes to start a Crosstrek? :D

And that's not even considering having the dash cam in parking mode, which will be on during the day while the solar panel is, hopefully, charging the battery, and at night when it's not.
 

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It got less cloudy, though not totally clear and it got up to 2.1W at solar noon. So, hopefully on a good day it will get up to 5W or more. Still pretty crappy for a 30W panel but obviously that rating is the max under ideal conditions, not behind a tinted sunroof on a hazy day. That's why I got the highest output panel I could find that would fit.

Even so, I'm beginning to wonder if it's really going to solve the problem. On a typical day it will be parked in the sun for about 8 hours, so assuming it starts out at about 2W, peaks at 6W around noon, then tails off to nothing in the evening, that's about 2Ah. Is that really going to make a difference to a 62Ah battery? I guess every little helps but the car will have been started at least twice and only driven 5 miles each time. Anyone have any idea how much juice it takes to start a Crosstrek? :D

And that's not even considering having the dash cam in parking mode, which will be on during the day while the solar panel is, hopefully, charging the battery, and at night when it's not.
It will slow the rate of decline and that's about it. Your best bet may be still to charge the battery periodically but having the solar panel may reduce your need to do the charging to once a year.
 

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Discussion Starter #44
I did some of the wiring today since I got the proof of concept working yesterday. Because of the frame and mechanism around the moonroof, it's tricky getting the power cable out of the moonroof compartment and behind the headliner. There's a little gap here:

Moonroof.jpg

However, since it's between the tracks and the headliner, the cable has to be routed with the moonroof closed, and then over the top of the airbag to the door frame, to the A pillar. Took quite a bit of fishing... :D

Here's the panel installed, with the interior sunshade closed (no panel or wires visible inside the car):

Moonroof2.jpg
 

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Discussion Starter #45 (Edited)
We haven't had a clear, sunny day in weeks! WTF?

This weekend is nice but there was a marine layer this morning and now lots of high cloud. Highly unusual for March! We don't usually get the June Gloom until, well, June, and it burns off by noon. Dwasifar, is that considered poetry? :D

Anyone else having any luck with a solar panel?
 

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Discussion Starter #46
First totally clear sunny day that I've had custody of the Crosstrek... :D

Got 14.4V and 3.1W at solar noon. So, not spectacular for a 30W panel but it should top up the battery while it's parked in the sun all day. I've now hooked up the cam to the solar panel controller and will monitor the battery voltage...
 

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Discussion Starter #47
So far so good. After the first night (i.e. no solar power) with the cam in parking mode, the battery was down to 11.9V in the morning but after a couple of sunny days, running errands locally and the car parked in the sun it's up to 12.3V, which I haven't seen for a while. So that's encouraging.

Today I rerouted the wiring to make it tidier and to have the solar panel controller in the armrest cubby. So it's out of sight and most of the cabling is hidden but I can just open up the armrest to see the current voltage, whether there's enough juice from the solar panel to charge the battery, etc.

Another storm is on the way though. WTF? I may need to wait until the summer to see if this is really a viable solution.
 

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Discussion Starter #48
Well, after yet another storm, then a couple of sunny days, the battery was 11.7V this morning. The dash cam had shut off due to the low voltage protect. Grrr...

Dezlboy, how's your windshield solar panel doing?
 

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Discussion Starter #49
Got to experiment with the solar panel this week while driving around the Sierras. After hours of driving in bright sunshine it would get up to 12.5V (i.e. 90%, measured after stopping and resting for an hour or so), then 12.4v the following morning. So it's working.

I still think I need a better battery... :D
 

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Discussion Starter #50
Well, I turned the parking mode back on last night. The battery was 12.4V (80%) and this morning OAK said it was 12.0V (50%) before she started the car!

I'll do load tests with the cam on and off when I get custody tomorrow but it's looking like we'll need a better
battery to have the cam in parking mode.
 

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One of my 8th grade Physical Science students who was working on brainstorming ways to mitigate climate change suggested mounting wind generators on the roof of cars and powering the car from the wind. I could tell I needed to work a bit more on Newton's laws and energy conservation/creation when he did so.
 

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Discussion Starter #52
One of my 8th grade Physical Science students who was working on brainstorming ways to mitigate climate change suggested mounting wind generators on the roof of cars and powering the car from the wind. I could tell I needed to work a bit more on Newton's laws and energy conservation/creation when he did so.
Yup!

I'm thinking of trying to remove the tint from the sunroof but haven't tried that yet. I'm sure that would help. I'm not sure what kind of coating or film is used and how easily it can be removed. I'm also going to get a new battery before we head up into the mountains this winter. Just got the first snow last week...
 

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Yup!

I'm thinking of trying to remove the tint from the sunroof but haven't tried that yet. I'm sure that would help. I'm not sure what kind of coating or film is used and how easily it can be removed. I'm also going to get a new battery before we head up into the mountains this winter. Just got the first snow last week...
I thought the tint was "assembled" into the glass by flowing it as a layer. Didn't think anything except mechanical contact would actually remove it. I'm not sure but I don't think there is a chemical wash that I'm aware of. I saw a video once of how they flow the molten glass and I seem to recall it included a metallic tint, this may have only concerned building "plate" glass though.
 

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Discussion Starter #54
I thought the tint was "assembled" into the glass by flowing it as a layer. Didn't think anything except mechanical contact would actually remove it. I'm not sure but I don't think there is a chemical wash that I'm aware of. I saw a video once of how they flow the molten glass and I seem to recall it included a metallic tint, this may have only concerned building "plate" glass though.
I lost interest in this project when the battery was below 12v after being parked in the sun all day. I will be getting a new battery before we go up into the mountains again...

It's raining here! WTF?! 😸
 

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Tinted tempered glass usually has the tint layer in the middle somewhere, you wouldn't be able to remove it.

Incidentally, "clear" tempered glass is already supposed to block something like 70% of UV rays so that could be a limiter to your solar panel's production regardless.
 
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