Schematic Diagram

 It is true that if any one wants to try to direct mengghubungkan between supply with batteries then the batteries can be sure will be filled. But the current flowing through a charged battery can not be controlled and if the battery is full, the batteries will be damaged or worn out if it remains on the short circuit condition.

Working Principle Battery Charger

By the time we put an empty battery charging terminals, transistor Q1 will be activated immediately because the current flows through R1 and would trigger a transistor Q1 base. In this condition the flow that would fill the batteries mostly comes from the collector of Q1 is connected directly to the positive terminal of supply. Then during the charging process increases the battery voltage will increase the current flowing in Q2 base via 10 Kohm R5, VR1 and diode D2. VR1 is a component that is used as an initial calibration to determine the exact position in the planning process of switching circuit. For VR1 you can use a trimpot or potensio according to your taste. At the beginning of filling, arrange potensio at position D3 LED indicators on the condition of death, and the current flowing into the collector of Q1 is not too big and not too small.

If the battery is fully charged, the LED indicator will light up automatically because of an increase in voltage on the battery charge will cause the increase of current flowing at the base of transistor Q2 and will terminate the charging cycle due to transistor Q1 having a cut-off due to lack of base current. Why on condition Q1 base current will experience a shortage of this is because almost all the current flowing in R1 10 Kohm will switch to a diode D1 which is logically connected directly with ground experience due Q2 saturated.
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Component List
1. Resistors: R1 (10 Kohm), R2 (680 ohms), R3 (100 Kohm), R5 (10 Kohm) and VR1 (Potensio / trimpot = 100 Kohm)
2. Diodes: D1 & D2 (IN4002) and D3 (Led)
3. Transistors: Q1 and Q2 (2N3904)
4. 9 volt power supply

Do you drive an older car without an automatic "lights-on" warning circuit? If so, youve probably accidentally left the lights on and flattened the battery on one or more occasions. This headlights reminder circuit will prevent that. Its more complicated than other circuits but its also more versatile. As shown, the circuit uses two low-cost ICs. IC1 is a 555 timer which is wired to operate in astable mode. Its output clocks IC2, a 4017B decade counter. IC2 in turn drives a row of indicator LEDs and also resets IC1 (after about 10s) via transistor Q2.

The circuit works like this:

when the ignition is on, transistor Q1 is also on and this pulls pin 4 of IC1 low. As a result, IC1 is held reset and no clock pulses are fed to IC2. Conversely, if the ignition is turned off, Q1 will turn off and so IC1 will start oscillating and sound the piezo siren. At the same time, IC1 will clock IC2 and so LEDs 1-10 will light in sequence and stop (after about 10s) with the last LED (LED10) remaining on. Thats because, when IC2s O9 output (ie, pin 11) goes high, Q2 also turns on and this pulls pin 4 of IC1 low, thus stopping the oscillator (and the siren).

Circuit diagram:
Note:

That different colored LEDs are used to make the display look eye-catching but you make all LEDs the same color if you wish. Installing optional diode D1 will alter IC1s frequency and this will alter the display rate. Finally, if the lights are turned off and then back on again, the alarm will automatically retrigger. LED1 is always on if the lights are turned on. If you dont want the LED display, just leave the LEDs out.