Newbie advice on a project

Thread Starter

Jerald Lifsey

Joined Aug 27, 2018
I bought an Auto Vent/solar powered car window venting fan for my car online. It was crap. The solar cell powered the fan/blower (you could see the blower spinning) but couldn't feel any air coming from it.
I had an idea by combining two things to make a better solar powered car window venting fan.

I've thought about getting a Sunway Solar Car Battery Charger 12V Battery Trickle Charger Maintainer


a OPOLAR 4 Inch USB Desk Fan

and having the solar panel power the desk fan after I build some box to put the fan into to hang from in my car side window.

Just don't know how to connect the two together.

I'm pretty sure I couldn't just splice the wires on the fan and the solar panel and too bad there's not some kind of female DC car adapter to USB....

How would you do it?



Joined Jan 15, 2015
The potential problem I see is on a good day in bright sun the output of the solar power unit is 15 Volts @ 3 Watts so we get 3 Watts / 15 Volts = 0.2 Amp or 200 mA. Finding data for the fan was another story but in a Q&A I found where the fan current was measured at 0.2 Amp or 200 mA. So under ideal conditions on a good day the battery maintainer would be using max output just to run the fan. That assumes the numbers to be legit.

If I lived in a desert and wanted some airflow in my truck I would likely get myself a cheap low power thermostat and just power a low power fan off my trucks 12 volt power. A little fan is not going to run down a battery all that fast. Figure even at 200 mA that is 0.2 amp hour or for 5 hours operation it will consume 1 amp.

Just My Take...


Joined Aug 7, 2008
Is the fan 5V ?, then might need a buck converter. Another addition might be a " Solar Gleaner" to burp the fan when solar power is low. The gleaner charges a capacitor to a set V
& when high enough dumps it into load.Solar Gleaner # 4 00000.jpg