A smart dongle device may comprise a connector configured to plug into and be removable from an ECU/diagnostic connector of a vehicle, a transceiver configured to communicatively connect with a remote device, and a processor and a memory having a program communicatively connected to the processor. The processor may be configured to read vehicle information including at least one ECU output from the ECU connector, store the vehicle information, process the vehicle information, and send the vehicle information to the remote device. The processor may further be configured to determine energy levels stored by a vehicle before and after a trip and generate a remaining range and a total energy capacity based in part on the energy levels, wherein the total energy capacity of the vehicle is not directly available through the ECU/diagnostic connector.