The Dart3-4G has a 200mAh internal backup battery, while the Dart3-2G has an 850mAH internal backup battery. This allows for external power removed alerts to be sent immediately if the unit is unplugged or dislodged, and tracking to continue for some time. 

When stationary, the device turns on the GPS periodically to get updated satellite information, speeding up subsequent fix acquisition. It will also heartbeat hourly by default. 

When on the move, the device is constantly connected to the network, and constantly acquiring GPS fixes (modem and GPS stay on) - to allow for detailed 'live-tracking'. 

On default settings (hourly heartbeat), approximate battery life is as follows:

• 9 days if sitting stationary for the Dart3-4G, and 20 days for the Dart3-2G
• 3.2 hrs in trip for the Dart3-4G, and 6.1 hrs in trip for the Dart3-2G

Adjusting in-trip parameters will not impact in trip battery life - so 3.2 hrs and 6.1 hrs in trip is the maximum we will see. 

GPS Freshen Parameter

• When stationary, by default, the device turns on the GPS every 2 hours to 'freshen' and update its satellite information. This speeds up subsequent GPS Fix acquisition. When the next trip is started, it will get a fix quickly (often under 10 seconds)
• Setting this parameter to 0 disables the GPS freshen
  • This will increase battery life substantially
  • The device will take marginally longer to get a fix when a new trip begins
• Alternatively, the freshen could be extended to 4hrs (the data gets stale after this time)
• Note the freshen is only helps GPS performance if it succeeds anyway - i.e. if we are parked in a garage and can't see satellites, 'freshening' doesn't help us - as the device can't get the updated satellite data. 

In general, it is best to leave this parameter on default unless we have specific requirements.

Battery Life with 6hr heartbeat and Freshen Disabled

If we are in good cellular coverage (meaning uploads don't cost too much) - we can expect around 100 days battery life.

Using the Dart3 with Intermittent External Power

The Dart3 is designed with the expectation that an 8-36V DC supply will be present at all times. The backup battery is designed around allowing for tamper/external power removal alerts. 

However, some applications (such as wiring into trailers) result in power only being available intermittently. In general the Dart3 will cope with this, but there are a few key considerations:

• LiPo rechargeable batteries degrade over time, and only withstand a finite amount of charge/discharge cycles before they can no longer hold charge. 
• For such applications a G70 (Larger back up battery), or battery powered device may be preferable.

Dart3 Battery Life Calculator.xlsx