I see the device Sceadwian mentions as a relay. However I don't get why it is being turned on by a 2N2222 transistor. Anytime the Vcc power switch (S) is on the transistor is driven into saturation and turns on the relay. The relay coil voltage is apparently Vcc so why use a transistor to turn it on? Since the relay looks to be a SPDT relay and anytime Vcc is not applied the N/C contacts will allow the lamp to discharge the battery. Also as mentioned the diodes have no identification or values? So what is the objective here? Vcc applied, lamp off, battery charge. No Vcc lamp on battery discharging?
Ron