The Hawk Pro is the new name of the original Hawk PCB.

The Hawk Lite is a new PCB option for the Hawk IoT Datalogger.

The Hawk Lite is compatible with lower energy, lower cost batteries than the Hawk Pro.

• It is only compatible with Alkaline D Cell batteries

The Hawk Pro in turn has more flexible power options.

• It is compatible with external power e.g. Solar or mains power.
• It can have an internal LiPo battery for backup in case of external power interruptions.
• It is compatible with LTC D Cell Batteries

Yes, the Hawk is fitted with a 3500mAh back up battery, and charging circuitry. A solar panel can be connected directly to the external power input on the device, and will charge the battery. A 12V panel, 5W min is required. For example https://www.jaycar.com.au/12v-10w-solar-panel-with-clips/p/ZM9051. See Connect a Solar Panel to the Hawk

Around 50Hz - ensure to test thoroughly higher pulse rates to ensure that none are missed.

The number of records is dependant on what sensors are used.

If an SDI-12 probe is used, more space is used per record. 
If using an SDI-12 probe, the Hawk can store approximately 40 000 records

Otherwise, it can store approximately 80 000 records - that is nearly 1 year of records taken every 10 minutes!

To ensure waterproof cable entry into the housing, the diameter of the cable used should be between 2.5mm - 6.5mm. It should also be an extruded cable with 2 or more cores.

If the external voltage is below 3V, it is rounded down and displayed as 0V. We have a specified minimum of 6V for the external voltage.

No, you should not use the onboard Hawk temperature instead of a temperature probe. This is because the temperature reported in the device logs could be very delayed. The Hawk samples temperature after a task finishes and before an upload. In a heartbeat-only case, the device samples temperature after it logs the heartbeat. For example, if the device heartbeats every 6 hours, the temperature reported in the heartbeat will be 6 hours old.

Two reasons for a Hawk 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: Hawk - Battery Life Estimates