1. Stored energy, harvesting of energy, battery life
The main assumptions made when designing and building the system was long battery life,
comfort, and convenience of use. All processes related to harvesting, distribution, monitoring, control, and protection systems are fully automated, which has made it much easier to use the trailer for expedition and recreation purposes.
Energy resources - use of two sealed batteries, made in the AGM technology, safe,
with the capacity of 150 Ah, result in total energy available equal to 300 Ah.
At Poland's latitude, during the summer, in sunny weather, the photovoltaic panels on the roof, with the total power of 450 W, provide as much as 23 A of direct current.
The effective 3-stage charger, compliant with the EUROBAT standards, with the capacity of 12
V/50 A, reduces the battery charging time to a minimum.
2. Data concerning battery life
The charging time of discharged batteries from a 230 V mains when charging from the photovoltaic panels is not possible is a maximum of 8 hours. The minimum time of sporadic charges of discharged batteries from a 230 V mains is 4 hours.
The charging time of discharged batteries from the photovoltaic panels, if charging
from a 230 V mains is impossible is a maximum of 15 hours, or about 3 days of sunny weather.
The battery life, if the electric water heater is not used, without charging from a 230 V mains and without charging from photovoltaic panels, with the refrigerator working continuously and if the 12V/230V/600W converter and the on-board appliances are used reasonably and in a controlled matter is more than 30 days.
If the electric water heater is not used, without charging from a 230 V mains and with charging from photovoltaic panels during sunny weather, with the refrigerator working continuously and if the 12V/230V/600W converter and the on-board appliances are used reasonably and in a controlled matter is more than 30 days, the system is self-sufficient.
If the electric water heater is used, the battery life depends on the number of water heating cycles and on the selection of the FULL or SEMI heating time.
3. Electric water heating system
There are two water heating modes:
FULL - 3 hours of heating, with water temperature increased by 16 °C
SEMI - 1.5 hours of heating, with water temperature increased by 8 °C
The consumption of energy by the water heating system is controlled by a microprocessor. The controller for the water heating process monitors the status of the batteries and the current output of the photovoltaic panels. From the system consisting of the connected photovoltaic panels and the batteries, the excess energy from the photovoltaic panels is first used to heat up the water and only then the energy accumulated in the batteries is used. The charging status of the batteries and the level of water in the tank are monitored at the same time.
The charge monitoring system automatically stops operation when the level of charging drops below 50% (150 Ah) - this is indicated by blinking of the STOP button.
The charge monitoring system automatically stops operation when the quantity of water in the tank drops below 45 liters - this is indicated by blinking of the stop button.
Consumption of energy in the water heating process without charging from photovoltaic panels (depletion of the energy stored in the batteries)
FULL - 132 Ah
SEMI - 66 Ah
Consumption of energy in the case of water heating at full output of the photovoltaic panels
(depletion of the energy stored in the batteries)
FULL - 63 Ah
SEMI - 31.5 Ah
4. MULTI-VL metering system
The MULTI-VL device measures:
- the battery voltage;
- the level of water in the tank;
- the quantity of gas in the cylinder.
5. Protection of electric circuits
In the 230 V mains system:
- RCD protection;
- overcurrent protection of type B;
- a 230 V switchboard in an IP 65 enclosure.
In the 12 V system:
- automatic, thermal, repeatable protections located on the main board;
- ATO protections located in an electrical compartment.
6. Electric circuits
In the 230 V mains system:
- a 230 V outlet in the galley;
- a 12 V/230 V/600 W converter with an outlet on the radio board;
- a circuit of the 12 V/50 A mains charger.
Circuits supplied from the 12 V system:
- gas cooker;
- water pump;
- electric toilet (valves);
- comfort fan;
- 12 V/USB sockets;
- water heating system;
- overpressure fan, with remote control;
- stroboscope lamp, with remote control;
- electric roof lifting.