Picked a 5V panel over a 12V for my phone charger build and regretted it

I had to choose between a 5V 6W panel and a 12V 10W panel for a portable phone charger I wanted to build last month. The 5V was smaller and cheaper at $12, so I went that route thinking it'd be simple. But even in full sun, it barely pushed 0.5A into my phone, and on cloudy days it was useless. My buddy used the 12V with a buck converter and gets a full charge in 2 hours. I should have spent the extra $8 and the hour to wire in a regulator. Has anyone else had luck pairing a 12V panel with their phone charger setup?

2 comments

2 Comments

james6723d ago

Wait hold up @leo_campbell, you're saying the cable length alone could cost me that much current? I was using a cheap 6 foot cable from a gas station, never even thought about the voltage drop. That might explain why even in direct sun at noon my phone showed "charging slowly" instead of a normal rate. Guess I need to swap that wire before I rethink the whole panel setup.

leo_campbell3d ago

That 0.5A number is brutal. Were you measuring it with a USB meter or just going off the phone's battery indicator? I've found those cheap inline meters tell a different story than what the phone actually accepts. Also, what kind of cable were you using? A long or thin USB cable can drop voltage like crazy at those low currents, making a bad situation worse even if the panel itself isn't the main problem.