The $10 Solar Powered Wikipedia Phone eReader MP3 player GPS Unit

How useful is an old cellphone? How about one which is solar powered?

The reality is that solar powered cellphones are pretty darn useless. I have a bunch of different types of solar panels, and the best of the portable ones would still need your phone plugged in for hours a day, in direct sunlight, outside (no UV proof glass in the way) in order to get a full charge. 

A solar panel on the back of your cellphone? Well, how much time does your cellphone spend outside, on it's face, on sunny days? My guess would be none, until it drops out your pocket on the way to the beach (quick tip - get rid of those hipster short shorts). 

That is unless it's not your cellphone. Just "a" cell phone. Specifically the Samsung Replenish - the only cellphone which comes with an optional solar-charger back. Namely one I bought for $4.55 (including shipping!) on eBay and then added a new in box Samsung battery cover. And an old used 8gb microSD card I had lying around. 

Total Cost: $11.45 - but I bet you could get it down if you bought a used solar cover. 

So what is it used for? Well, my plan for this is to use it entirely away from an internet connection. The reason for this is the same as the solar power - I plan on using this mostly on my boat or hiking in areas where while I may have a cell connection, I don't have grid power. 

The phone itself? A pretty nice keyboard with a relatively small and crappy screen - 2.8in and 320x240 pixels. An old 600mHz processor and a pretty small battery round it out. Solar charging works well for me - about 5-20% boost per hour in airplane mode depending on light conditions (and this is outside in directly sunlight).

So what can you use it for? A lot - mostly redundant with your main cellphone - but without caring if the battery goes flat in the middle of nowhere:

Step 1: Wikipedia

https://play.google.com/store/apps/details?id=in.bitmagic.wiki.offline&hl=en

This app works perfectly for me. I have the free version which uses about 4gb of my 8gb card, and gives the top 2 million articles - so I don't think you'll run out any time soon...

Step 2: Music

With about 4gigs to play with I loaded up quite a few of my favorites. The cellphone speaker is no better or worse than most, and perfectly fine for the campfire or hanging out on the boat. 

Step 3: Books

eBooks take up about as much space as Obama's foreign policy victories. I loaded up 30-40 of my favorites. I'll probably never read them on this screen when I could use my kindle instead, but again - they take up no space... so why not. 

Step 4: GPS

No internet? You still have a GPS chip and everything that entails. For my boat I use Polaris navigation - where I can see Lat/Lon, speed and heading:

https://play.google.com/store/apps/details?id=com.discipleskies.android.polarisnavigation&hl=en

This works pretty well and is a great backup to a primary system. There are lots of similar apps available which give your GPS info with minimal battery draw. 

Step 5: Delete Crap

This phone will be off-the-internet so delete everything related to it being a phone. All Google apps, and really pretty much everything except the above apps. 

Step 6: All set!