12V battery voltage logger with SD card and serial LCD Photo: https://pbs.twimg.com/media/BrNnBGaIcAAuJAc.jpg:large
Hardware: *Arduino Uno *NuElectronics SD card shield with Real Time Clock *Serial 20x4 LCD (LCD117) http://moderndevice.com/product/lcd117-serial-lcd-kit/
*Voltage divider into ADC input: 890k on top and 470k on bottom. Max voltage 16.5V