Due to limitations in the phenomenon itself, BatteryDrop is unable to accurately predict the charge of batteries with less than 40% charge remaining.
Currently supported battery types:
This application was inspired by a Princeton study, which can be found here: https://www.princeton.edu/main/news/archive/S42/72/95S25/index.xml?section=topstories
It explains the science behind this phenomenon, but also shows that it is impossible to detect a difference in heights below 50%. (Our system works in increments of 20%, which is why 40% is the lowest detectable charge.)