Quantity   Component name
3 × Raspberry Pi 3 with SD card and power supply
1 × INA219 High Side DC Current Sensor Breakout link : https://www.adafruit.com/product/904
1 × ACS712 based current sensor link : http://www.allegromicro.com/en/Products/Current-Sensor-ICs/Zero-To-Fifty-Amp-Integrated-Conductor-Sensor-ICs/ACS712.aspx
1 × LiPo Fuel Gauge link : https://www.sparkfun.com/products/10617
1 × 6V Solar panel example : https://www.adafruit.com/product/1525
1 × USB / DC / Solar Lithium Ion/Polymer charger link : https://www.adafruit.com/product/390
2 × LiPo batteries 3.7 mV
1 × Relay Module example : http://wiki.sunfounder.cc/index.php?title=4-Channel_High_Level_Trigger_Relay
2 × Breadbord and wire to connect all the components