message: Proposed fix to issus
  Battery voltage is reported as 3.x volt on a 4S battery. This is typically one cell only.  Sum the voltage of all cells to obtain the total battery voltage.
diff: @@ -1076,7 +1076,13 @@ void TelemetryImpl::process_battery_status(const mavlink_message_t& message)
  Telemetry::Battery new_battery;
  new_battery.id = bat_status.id;
  - new_battery.voltage_v = bat_status.voltages[0] * 1e-3f;
  + new_battery.voltage_v = 0.0f;
  + for (int i = 0; i < 10; i++)
  + {
  + if (bat_status.voltages[i] == UINT16_MAX)
  + break;
  + new_battery.voltage_v += static_cast<float>(bat_status.voltages[i]) * 1e-3f;
  + }
  // FIXME: it is strange calling it percent when the range goes from 0 to 1.
  new_battery.remaining_percent = bat_status.battery_remaining * 1e-2f;
  