How the device is ultimately installed is dependant on the application. E.g.

• Are inputs to monitor duress buttons/PTOs etc required?
• Is driver ID/Immobilisation required

See the following guides. Elements of each may be required for your specific application

• 3-Wire Install - [Dart3]
• Monitor a PTO/Fuel Pump - Dart3
• Set Up A Panic/Duress Button - [Dart3]
• Immobilisation Install - Asset can be immobilised from server
• Immobiliser Install - Asset starts after valid Driver ID Scan

Yes, there are a wide variety of DM and 3rd party readers available that will work with the device. To read a variety of card types and suit many applications, see - Dart3 - Driver ID Options

Yes

• Immobilisation Install - Asset can be immobilised from server
• Immobiliser Install - Asset starts after valid Driver ID Scan

Yes, see External Power Removed Alerts [Dart3]

Yes, see Harsh Event Setup - Dart3 and Accident Detection and Reconstruction + Accident Data Exports - Dart3 
For speeding alerts, the device will report it's speed, and then the end platform can alert on this.

We use high quality components and make use of GPS Aiding Data to ensure the best performance. Typically, speed is accurate to within +/- 2km/h. But GPS isn't perfect or 100% error free, it can in rare instances be wrong, see here: GPS Settings and GPS Accuracy

Yes, the Dart3 can be connected with an Analogue temperature probe to measure and report temperatures.

However, the Dart3 is not currently compatible with 1-wire temperature probes. The current FW (v1.16 at the time of writing) only supports iButton over the 1-wire interface.

Two reasons for a Dart3 to record 0V for the internal battery reading:

Internal Battery Plugged in:

If the internal battery drops below 3.35V it will record 0V.

Internal Battery Unplugged:

When the devices exceed in 40 deg C (or below 0 deg C), the charger is disconnected to preserve the battery health. Usually with the internal battery connected, the internal battery reading would read 100 mV lower after the charger is disabled (4200mV -> 4100 mV) . If the internal battery was disconnected and the device is operating as usual, in acceptable conditions, the charger would be powering the battery terminals and thus the internal battery readings would read 4100mV. Once the device is outside the safe temperature zone, the charger stops powering the internal battery terminals and thus the datalogs will read 0V.

For information detailing how long your backup battery will last, navigate to: How long will my back-up battery last? - [Dart3]