Making a simple solar-powered lighting system, a few concerns
Does the circuit make sense and do you see it working?


The circuit is rubbish (I'm not noted for my human skills BTW) because the top NPN will only ever produce about 8.2 volts at the emitter to charge the battery - you need to consider using a PNP transistor wired differently.

Also the two voltage sources are floating i.e. their negative connections are floating and please don't whine saying that I should presume they are connected to ground.

Accuracy is something that needs to be a commitment in electronics.

Also, the LED shown in red isn't described as being a 12V type and therefore it might need a current limiter BUT why is it there at all when you have the other LED in parallel?

I also read that you are using lamps but, please get used to the fact that a circuit diagram (and what it contains) is the gospel and, contradicting it with statements about lamps is really just a sign of laziness when using the circuit diagram editor. Get it right in the editor.

In other words, draw an accurate circuit to the best of your ability and let that speak for itself. Transistors all round are probably the best option when it comes to Q3.