Good afternoon. Due to the abnormally strange weather this year, it will not hurt to have an emergency light source and the ability to charge a mobile phone from it in the country or in a country house. This kit is already in my homemade , but this one is made in a moisture-proof case and two USB sockets for charging the phone are added to it.
the bulbs are made of the same 3.7V diodes but the housing of the bulbs is also moisture-proof. There are no resistors in the soldering circuit of the bulbs. In the first homemade there was a resistor but I threw it away right away.
The diodes are all soldered in parallel and connected directly to the batteries through the switch, so it makes no sense to draw a circuit.
In the box there is a charging unit; voltage is input from the solar panel; it charges 8 lithium batteries with a total capacity of 20,000 mA and 2 super capacitors of 2.7 V 100 farads which are connected in series and connected to lithium which are all 8 soldered in parallel.
Diodes this time set a pure white glow.
In cloudy weather, this installation shone for 5 hours, until the batteries were low and the luminescence did not decrease by half. If you forget to turn off nothing wrong - the automation itself will cut down the bulbs as soon as the batteries reach a critical discharge.
Solar modules are installed in a metal box with ears for fastening, all contacts on the back of the elements must be filled with silicone.
This device is always ready to work in the event of a power outage. The panel can be fixed to a window on the inside of the room. There is no need to mount on the street.