System operation

The present documentation section describes how to monitor the charging process with the skycharge-cli SDK tool and guides you through the first charging test.

skycharge-cli

skycharge-cli is a simple command line tool allowing remote monitoring and management of your Skycharge systems. skycharge-cli can be invoked from the charge source Linux OS, from a Linux computer connected to the same LAN of the charge source, and from the cloud.

To invoke skycharge-cli from the charge source use:

skycharge-cli [command] [(params)]

For example, the following command will show all the information about the charging process:

skycharge-cli monitor --pretty

Timestamp:       2021-11-17 10:29:54.706
Dev state:       SCANNING
Voltage:         19.197V
Current:         0.000A
Power:           0.000W
Energy:          0.000Wh
Charge:          0.000Ah
Source temp:     26C
Sink temp:       0C
Charging:        00h:00m:00s

To invoke the same command from the cloud use:

skycharge-cli [command] [(params)] broker.skycharge.de 5555 [--id <dev-id>] --conffile <file>

Example:

skycharge-cli monitor --pretty broker.skycharge.de 5555

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Skycharge SDK

skycharge-cli is a tool which is part of the Skycharge SDK. All the Skycharge systems can be also programmatically managed and monitored through the powerful and open Skycharge SDK which is documented in the relevant documentation section: https://support.skycharge.de/docs/sdk

The first charging test

When the system is powered on, the charge source applies a low DC voltage continuously to the contact solution. When the contact unit comes in contact with the contact solution, the charge source recognizes the charge sink and charging begins.

At this point you powered on the system, are logged into the charge source, and configured the system. When the contact unit is not in contact with the contact solution, the system remains in a scanning state.

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System states

For more detailed information about the System states, please refer to the relevant SDK documentation section: https://support.skycharge.de/docs/system-states

Now start monitoring the charging process with the following command:

$ skycharge-cli monitor --pretty

Timestamp:       2021-11-17 10:29:54.706
Dev state:       SCANNING
Voltage:         12.005V
Current:         0.000A
Power:           0.000W
Energy:          0.000Wh
Charge:          0.000Ah
Source temp:     26C
Sink temp:       0C
Charging:        00h:00m:00s

As you can see, the system is in SCANNING state and the factory scanning voltage is 12V. No current is flowing at the moment.

Now connect the contact unit with contact solution and right after you should see an output similar to this:

$ skycharge-cli monitor --pretty

Timestamp:       2021-11-30 21:20:22.025
Dev state:       PRECHARGING
Voltage:         18.633V
Current:         1.334A
Power:           14.184W
Energy:          0.221Wh
Charge:          0.011Ah
Source temp:     25C
Sink temp:       20C
Charging:        00h:00m:17s

The system entered the PRECHARGING state.
The purpose of this state is to slowly start charging the battery by gradually increasing current (more information about the PRECHARGING parameters can be found in the system configuration section). When the precharging phase is complete, the system enters the CHARGING state:

$ skycharge-cli monitor --pretty

Timestamp:       2021-11-30 21:20:43.155
Dev state:       CHARGING
Voltage:         19.658V
Current:         2.377A
Power:           46.727W
Energy:          0.497Wh
Charge:          0.025Ah
Source temp:     25C
Sink temp:       21C
Charging:        00h:00m:38s

The system now entered the CHARGING state.
The system will keep this state until one of the following conditions is verifies:

1. the current drops below the threshold specified through the sink-cutoff-min-current-ma parameter;
2. the system elapses the maximum charging time specified through the sink-total-charge-secs parameter;
3. the electrical connection is physically interrupted (the drone/mobile robot moved away).

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Short condition

If an unrecognized conductive object shorts the contact solution elements, the system deactivates only the shorted elements until the short condition is removed. When the object is removed, the functionality is immediately restore.

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Detection delay 1

When the contact unit comes in contact with the contact solution, the system enters the charging state within a few seconds. A delay is introduced in order to take into account the time required for the contact unit to stabilize on the contact solution after a possible bump due to the landing/docking procedures.

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Detection delay 2

When the contact unit disconnects from the contact solution, the charge source waits for five (5) seconds before attempting a new charge sink detection.