Charging Questions - General Programming
 

Hi guys I'm not sure if this is the best place to post this but I couldn't find anywhere else.

Would it be possible to program a cell phone charger to detect when a phone is at 20% and then it will start charging? But it won't start charging before 20%. Then it will charge it up to 99% and then stop charging until the phone reaches 20% again.

Let me know if you have an idea how to go about this. Specifically for iPhones and Galaxies, etc. The most popular phones.
Even if you can't give me specifics maybe just give me an idea of how to do it? I am not a programmer so maybe try to keep the lingo somewhat easy for me to understand, Thanks!

-Brandon