Or is there maybe a way that you could measure if its full or not based on and amperage reading? Or would a amp reader also just show the amp output from the charger. It probably would. (in case you guys haven't realized yet, electricity isn't really my thing

)
I could just use a volt reader like this :
https://www.adafruit.com/products/460 but so no need for a tablet interface, but it wont be effective, since it would just show the volt output of the charger right?