PROJECT DESCRIPTION
The system has two batteries. When both the batteries are charged, load is connected to the first battery (BATT.1) by default. If this battery’s voltage goes below the defined level, the load shifts to the second battery and the first battery starts charging. Similarly, when the second battery gets discharged, the load is shifted back to the first battery and the second battery starts charging. The system also monitors solar voltage. If the voltage is not sufficient for charging, the battery gets charged through the battery charger driven by AC mains.The program is written in ‘C’ language and compiled using HI-TECH C compiler along with MPLAB to generate the hex code. The generated hex code is burnt into the microcontroller using a suitable programmer with configuration bit settings. The configuration bits are shown in Fig. 2. The program is easy to understand.Connect two 80W solar panels in parallel to CON1 and an off-the-shelf available 12V battery charger to CON2. Connect two 12V, 80Ah batteries at CON4 and CON5. You can use 12V, 150Ah batteries for better backup, but this will increase the charging time. You need to select the maximum load in such a way that the duration of discharge for the active battery is more than the charging time for the other.
Take 12V LED strips from market to build the LED lights. You can connect strips in parallel to increase the lumens. But ensure that the overall wattage of all the lights is less than the maximum calculated load as mentioned above.
ADDITIONAL INFORMATION
Connect two 80W solar panels in parallel to CON1 and an off-the-shelf available 12V battery charger to CON2. Connect two 12V, 80Ah batteries at CON4 and CON5. You can use 12V, 150Ah batteries for better backup, but this will increase the charging time. You need to select the maximum load in such a way that the duration of discharge for the active battery is more than the charging time for the other.
Take 12V LED strips from market to build the LED lights. You can connect strips in parallel to increase the lumens. But ensure that the overall wattage of all the lights is less than the maximum calculated load as mentioned above.