Recall the earlier low battery indicator circuit using transistors, where the low battery level was indicated using just two transistors and a few other passive components.

Solar charging can work well for you, but you’ll need to plan before you buy to make sure you get the best panel for your needs. Connecting them directly would drag the panel voltage to the battery level making things inappropriate. As we know the IC 7812 will produce a fixed 12V at the output which cannot be used for charging a 12V battery. The 3 diodes connected at its ground (GND) terminals is introduced specifically to counter this problem, and to upgrade the IC output to about 12 + 0.7 + 0.7 + 0.7 V = 14.1 V, which is exactly what is required for charging a 12 V battery fully. The charger comes with a Micro USB cable that you can plug into a power source, with a more modern USB-C input if you want to use a USB-C cable instead of a Micro USB. Unfortunately, the unit doesn't have the USB power adapter that goes into your wall outlet, requiring a 5V 2A adapter.As the input current rises, the battery starts drawing more current, this build up a voltage across R3 which is translated into a corresponding base drive for the transistor. After dusk, when the solar voltage becomes sufficiently low, the relay is no longer able to hold its N/O position and flips to the N/C changeover, connecting the battery with the LED module, and illuminating the array through the available fully charged battery power. watts x 2 plus 8 watt gives a total of around 80 watts which is the total required consumption level here. The above explanation reveals how the IC LM338 can be simply used for making an useful solar LED light circuit with an automatic charger. 4) Automatic Solar Light Circuit using a Relay Car batteries are under constant demand, even when the car is switched off. The battery has to start your car, demist the windows, keep the alarm system running and generally power many functions drivers take for granted. It’s little wonder that they can lose charge over time and need a top-up. In an ideal world, you’d probably just use a mains battery charger but not everyone can park in easy reach of a plug. That’s where solar car battery charges come in.

You can even charge your battery by using the crocodile connectors that are provided and connecting them directly to your car battery under the bonnet. This isn’t as neat a connection and you’ll have to lift your engines bonnet and leave it up to charge, but at least you have this option. What Is an EOBD Connector

The total forward drop of the combined diodes would be around 5V, plus battery charging voltage 14.4V gives around 20V, meaning once connected with all the diodes in series during peak sunshine, the panel voltage would drop marginally to may be around 19V resulting an efficient charging of the battery.

Specification: Peak Power Output: 2.4 watt, Peak Volts Output: 12.7 volts, Optimum Working Current: 0.13-0.2 amps. The solar LED circuit is capable squeezing out the last drop of "joule" or the charge from the cell and hence the name joule thief, which also implies that the LED would keep illuminated until there's virtually nothing left inside the cell. However the cell here being a rechargeable type is not recommended to be discharged below 1V. The latest version of the product lists a new feature meant to detect and automatically repair damaged cells, but actual performance will vary. This output from IC1 is used for charging the street lamp battery during day time and peak sunshine.The battery should be replaceable when dead after use for 2/3 years/prescribed life by the rural/tribal user.