Android App Review: Solar Charger

This is a guest post from reader and listener Christopher Chancellor.

Over the past couple months, my Motorola Atrix 4G’s charging cord has been developing a kink at the point where the cable meets the phone connector. I didn’t think much of it, but this past weekend the cord finally stopped charging my phone. I looked around on the internet, and soon discovered that a new charging cord could end up costing me $10, including shipping! I didn’t particularly want to pay such an outrageous price, so I decided to Google around and see what alternatives I had. This is how I found the Solar Charger app by Szlab.

The App

The science behind it is fairly interesting:

Under normal operation, the LCD screen on your phone is polarized in such a way that it allows light to be emitted, which will naturally consume battery life. The Solar Charger app reverses the polarity of the screen in specific areas, allowing light to enter. In the areas the polarity is reversed, a dark pattern is printed that allows the maximum amount of light to be absorbed, just like the solar panels you see on top of houses. When the light levels get high enough, the light begins reversing the flow of electrons in your phone, effectively charging the battery. This process, developed by Szlab, is the first of its kind.

In other words, instead of letting light out, portions of the screen are changed to allow light in. This charges the battery.

The UI is simple. A solar cell pattern dominates the screen. At the top, a battery indicator shows how much juice you have left in your phone. A light meter just below it indicates how much light is entering your phone at any given time. This is useful in finding a good location to charge it. Once you’ve found a good location, you can make it disappear by tapping the meter. This allows the maximum amount of light to be absorbed into your phone, causing it to charge more quickly.

In the settings menu, you can choose between three different patterns: “Normal”, “Asymmetric”, and “Desert”. Here’s a comparison of the three to help the reader understand what they do:

• Normal: Your everyday pattern. Allows the maximum amount of light to come through, letting it charge in the fastest time.
• Asymmetric: This pattern is useful on cloudy days or in shady areas. It allows more light to be picked up in low-light conditions, but it’s not as efficient in bright areas.
• Desert: For areas that take in extreme sunlight. The brighter pattern protects your phone from taking in too much light at one time, which could cause the battery to overheat.

For 99 cents you can upgrade to the “pro” version of the app, which includes support for Samsung tablets and has farting noises to indicate the battery level while charging. The sounds themselves are of a high quality: crisp, clean rips that sound rather wet. The lower poots indicate lower battery levels, and the higher poots indicate higher battery levels. Upon a full charge, a procession of farts will play to the tune of Dixie. It’s an entertaining way of keeping up with how far along the charge is, but in public I would recommend turning down the volume.

Real-World Testing

For my test, I wanted to see how well it worked. I loaded up the app on my phone and took it outside, setting it down on the patio table where it was nice and sunny. The app indicated that it was beginning to charge, so I left it out and went inside to work on some homework. I went to go check on it about 10 minutes later and noticed that my battery life had gone from 20% to 50%. Impressed, I left it alone for another 10 minutes and came back. It had gone from 50% up to 80%! I decided to sit with it and enjoy the day, and within 12 minutes it was fully charged. This is quite an impressive feat, as my own wall charger took about an hour to charge my phone!

I waited a day, then took my phone outside and placed it in a shady spot to try out the asymmetric pattern. Note that my phone’s battery read at about 30%. About 8 minutes in, I found that the battery indicator was reading 40%. It was a bit slower than the normal pattern in a sunny area, but this was to be expected. I left it alone and checked back in 25 minutes. The battery now read at 60%. In the end, it took an hour and 18 minutes to fully charge my phone in a shady area.

Final Thoughts:

I am very impressed by the Solar Charger app by Szlab. The UI is well thought out, the science behind it is sound, and most importantly it gets the job done quickly. I wouldn’t hesitate to say that this has become my favorite app, as it allows me to roam in complete freedom from power cords. I highly recommend that Noisecast readers with Android phones try this out.

Okay fer cereal:

Disclaimer: This is a real app, but it does absolutely nothing aside from confuse the same people who used to believe that a monitor could take your picture. It may well ruin your phone to set it in the sun for any extended period of time. If you want to spoof your friends, go for it, but don’t expect actual charging to occur. Don’t blame us if you ruin your phone. We told you so.