Newbie question here...I can't seem to figure out what the problem is.
I built #2 in the diagram there since I didn't have a BC557 I replaced it with a 2N3906. For some reason, there is always a voltage getting back through the diode/transistor into the solar panel which subsequently discharges the battery pack. It charges just fine in the daylight but nothing stops the solar charger from draining the battery pack. This seems pretty simple but am I overlooking something obvious? I'm fairly sure since it's a PNP that I'm following the pinout correctly (EBC) with emitter being the top of the transistor in the schematic.
Currently, I have the lights disconnected, just wanted to verify if the design would work, which it doesn't. Bah.