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Old 08-08-2014, 06:11 PM   #7 (permalink)
silvermazda
EcoModding Lurker
 
Join Date: Jul 2014
Location: East Bay Area, CA
Posts: 25

Miata - '00 Mazda Miata
90 day: 27.57 mpg (US)

Celica - '91 Toyota Celica GT
90 day: 18.1 mpg (US)
Thanks: 3
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Quote:
Originally Posted by redpoint5 View Post
No way you will get the full 100W by placing the panel on your trunk.
The 100W rating assumes the panel is facing directly at the sun, and it's a bright and cloud free day.If a 100W panel is added to the car, you will want it to switch off with the ignition, otherwise you will fry your battery when the car is parked and not loading the solar panel.
I understand your concerns, but I have read a review on the specific solar panel which a user a state north of me -placed the panel on the ground and got 70w and I think at lease 20w when cloudy. Seems like a new gen one and not one of those boxy ones. Did I say it was 3mm thick? Let me link everyone and we can further discuss. And lastly, reply to your last point, I am. I know how batteries, especially my AGM doesnt need 18V to charge it. My batt charger charges at 15.5v, my car does 14.9 (which I think is a tad high), a honda does 14.3 (pretty darn good), spec for AGM is about 13.4volts. So first I'm trying to find how to step down the voltage. Thanks for your input.

Quote:
Originally Posted by oldtamiyaphile View Post
I tired a 40W panel for about six months. Most I ever saw out of it was 1.1A or about 15W. On the vehicle, the most I ever got was 0.8A or 11W.
I used an MPPT charge controller to make the most of the available current. Problem is as soon as you start the engine, the voltage jumps to ~14v and the controller detects this as a full battery and shuts off the panel while driving....The other issue is solar panels get extremely hot and transfer heat to the paintwork of the car (paint doesn't like being constantly baked) and onto the interior. Even with a 10mm airgap the underside of the roof was much hotter than the areas adjacent. A shame as solar panels work best in hot climates.
Some of this was answered above and I chose the 100W flexible because it's practically the size of my trunk lid. 40 inches by about 26 inches. THe thing about heat...hm. Let me think about that. It's an external type aka not hatchback, so it shouldnt affect me, and most of the year its 40-65*F, so I dont see another 10*F being a problem as the paint probs gets up to 90 in standing sun (correct me if I'm wrong). Did I say its not a conventional one aka glass frame, so I dont know what your 10mm will do.

Aerodynamically its nil. My stock cd is of .37. Put the top down it goes to .44, but sq ft is 18, but still 3mm wont upset the terrible transition the convertible top has against the trunk, this is not kamback. =)
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