Variables guide
| Name | Symbol | Description |
|---|---|---|
| temp | °C | Electronic board temperature |
| ds1 | °C | Cabinet temperature |
| vcc | V | Voltage of the board |
| inpd3 | 1 yes/0 no | Presence of current AC 220/120V |
| inpd4 | 1 closed/0 open | Status of the cabinet door |
| out0 | 1 on/0 off | Cooling fan operation |
| out5 | 1 enabled/0 disabled | Switch on / off |
| inpa1 | V | Module VSun PV |
| inpa3 | A | Current I/O battery 1 |
| inpa4 | V | Voltage of battery 1 |
| powwer1 | Wh | Input/Output instant battery. (+ input, - ouput) |
| energy1 | KWh | Energy balance battery 1. |
| t1 | C | External temperature |
| h1 | % | External relative humidity |
| pm01 | µg/m3 | Particulate PM 1 |
| pm25 | µg/m3 | Particulate PM 2,5 |
| pm04 | µg/m3 | Particulate PM 4 |
| pm10 | µg/m3 | Particulate PM 10 |
| co2 | Environmental CO2 | |
| m1 | m/s | Wind speed |
| m2 | 0-360° | Wind direction. |
Considerations
The values are sent from the various boards with a regular frequency set by the factory. The cabinets are supplied with an M2M card included in the cost of the SmartBox for 2 years from activation.
From the second year, a cost of €10/year per card is added.
The parameters set are adequate for the duration of 2 years, we strongly recommend not to modify the sending parameters in order not to excessively consume the traffic and cancel the benefit.
Temperature control
The monitored temperature values are three and precisely:
| controller_temp | Board temperature |
|---|---|
| ds1 | Internal cabinet temperature. This value is monitored with a probe inside the cabinet and indicates the internal air temperature level |
| t1 | Probe positioned outside the cabin which indicates the external ambient temperature in which the cabinet is positioned |
These three values must be checked in the periods of lower ambient temperature and higher ambient temperature. The second case is certainly the most important and must be constantly checked to avoid overheating of the system and especially of the LiFePo4 batteries.
High temperatures are mitigated by the presence of an air cooling system automatically activated by the system and which is activated when a temperature of about 40 ° is reached.
Note that the temperature value is measured in degrees centigrade.
Battery voltage and discharge curve
The battery voltage is the element to identify the system charge level. The smartboxes are produced with two types of 12V and 24V batteries made up of 4 cells and 8 cells respectively.
The discharge of the battery does not have a linear but a curvilinear trend. Here is the graph of the typical single cell discharge curve:
The voltage of the entire battery is always calculated as the sum of the individual cells. For example a 12V battery with 3.2V cells will have a voltage of 3.2 * 4 = 12.8v.
Keep in mind that a cell is considered to be completely discharged at 2.6V, so the battery 2.6 * 4 = 10.4
Below are the general specifications of the individual cells and their batteries.
| Description | Nominal voltage | Voltage 100% | Voltage 0% |
|---|---|---|---|
| Cell | 3,2 | 3,4 | 2,6 |
| Batt 12 V | 12,8 | 13,60 | 10,4 |
| Batt 24 V | 25,6 | 27,20 | 20,8 |
Attention, the BMS to protect the cell battery has a discharge cut-off threshold which disconnects the battery and prevents it from malfunctioning. It is important to always size the systems well to avoid system shutdown phenomena as much as possible.